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2. Retracted: 'Sensorless Control of Tubular Permanent Magnet Synchronous Linear Motor Considering the End Effect' [ASME 2020 International Mechanical Engineering Congress and Exposition, Volume 2B: Advanced Manufacturing, Virtual, Online, November 16–19, 2020, Conference Sponsors: ASME, ISBN: 978-0-7918-8449-2, Copyright © 2020 by ASME. Paper No. IMECE2020-23676, V02BT02A042; 6 pages; doi: 10.1115/IMECE2020-23676]
- Author
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Asme Asme
- Subjects
Engineering ,End effect ,business.industry ,Magnet ,Advanced manufacturing ,Mechanical engineering ,Linear motor ,business ,Exposition (narrative) ,Volume (compression) - Abstract
This paper was removed from publication at the author’s request, March 8, 2021. Copyright © 2021 by ASME
- Published
- 2020
3. Retracted: 'Turbocharger Radial Turbine Response to Pulse Shape Under Realistic Operating Conditions' [ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition, Volume 2E: Turbomachinery, Virtual, Online, September 21–25, 2020, Conference Sponsors: International Gas Turbine Institute, ISBN: 978-0-7918-8410-2, Copyright © 2020 by ASME. Paper No. GT2020-15237, V02ET41A025; 14 pages; doi: 10.1115/GT2020-15237]
- Author
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Asme Asme
- Subjects
Gas turbines ,Engineering ,biology ,business.industry ,Radial turbine ,Turbo ,Mechanical engineering ,biology.organism_classification ,Pulse (physics) ,Volume (thermodynamics) ,Turbomachinery ,business ,Exposition (narrative) ,Turbocharger - Abstract
This paper was removed from publication at the author’s request. February 18, 2021. Copyright © 2021 by ASME
- Published
- 2020
4. Retracted: 'A Numerical Study on the Shell-Side Thermal-Hydraulic Performance of a Hybrid Smooth and Spirally Corrugated Tube' [ASME 2020 Heat Transfer Summer Conference, Virtual, Online, July 13–15, 2020, Conference Sponsors: Heat Transfer Division, ISBN: 978-0-7918-8370-9, Copyright © 2020 by ASME. Paper No. HT2020-8996, pp. V001T09A010; 7 pages; doi: 10.1115/HT2020-8996]
- Author
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Asme Asme
- Subjects
Thermal hydraulics ,Materials science ,Heat transfer ,Shell (structure) ,Mechanical engineering ,Tube (fluid conveyance) ,Division (mathematics) - Abstract
This paper was removed from publication at the author’s request. October 2, 2020. Copyright © 2020 by ASME
- Published
- 2020
5. Erratum: 'Surface Bonding Graphene-Based Elastomeric Sensor: Preliminary Characterization of Adhesion Strength' [ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, Louisville, Kentucky, USA, September 9–11, 2019, Conference Sponsors: Aerospace Division, ISBN: 978-0-7918-5913-1, Copyright © 2019 by ASME. Paper No. SMASIS2019-5578, pp. V001T01A002; 7 pages; doi: 10.1115/SMASIS2019-5578]
- Author
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Salvatore Ameduri and Monica Ciminello
- Subjects
Engineering ,business.industry ,Graphene ,Intelligent decision support system ,Mechanical engineering ,Division (mathematics) ,Smart material ,Elastomer ,Surface bonding ,Characterization (materials science) ,law.invention ,law ,business ,Aerospace - Abstract
This erratum corrects errors that appeared in the paper “Surface Bonding Graphene-Based Elastomeric Sensor: Preliminary Characterization of Adhesion Strength” which was published in Proceedings of the ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, (V001T01A002), September 2019, SMASIS2019-5578, doi: 10.1115/SMASIS2019-5578.
- Published
- 2019
6. Delamination Behavior of Laminated Paper
- Author
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Kanta Ito, Takanori Kitamura, Hiroyuki Hamada, Wei Wang, Kenji Wada, Zhiyuan Zhang, Yuqiu Yang, and Mitsunori Suda
- Subjects
Paper recycling ,Paperboard ,Materials science ,Packaging industry ,visual_art ,Delamination ,visual_art.visual_art_medium ,Fracture (geology) ,Mechanical engineering ,Energy consumption ,Fracture process ,Composite material - Abstract
Paper recycling is an effective way in reducing deforestation and energy consumption. Therefore recycling paper and paper products has been widely applied in many areas, such as packaging industry, furniture decoration, temporary structures in building and so on. Paper products are made from plant fibers and they are laminated materials. So it is of possible to generate interlaminar fracture in the use of paper products, especially in the construction made of paper such as paper tubes which have been used widely. In order to improve the interlaminar performance of paper products and then improve the construction performance of paper products, delamination behavior of laminated paper has been studied in this paper. By a series of peel tests, comparative analysis about different paperboard were carried out. The cause of delamination behavior of laminated paper was analysis based on the detailed observation using a scanning electron microscope (SEM).Copyright © 2014 by ASME
- Published
- 2014
7. On the Design, Manufacture and Premature Failure of a Metal Mesh Thrust Bearing: How Concepts That Work on Paper, Actually Do Not
- Author
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Travis A. Cable and Luis San Andrés
- Subjects
Foil bearing ,Computer science ,Work (physics) ,Mechanical engineering ,Thrust ,02 engineering and technology ,021001 nanoscience & nanotechnology ,law.invention ,020303 mechanical engineering & transports ,Premature failure ,Thrust bearing ,0203 mechanical engineering ,law ,0210 nano-technology - Abstract
Oil-free micro turbomachinery (OFT) implements compliant foil bearings because of their minute drag and ability to operate in extreme (high or low) temperature. Prominent to date, bump-type foil bearings integrate an underspring thin metal structure that provides resilience and material damping; and while the rotor is airborne, acts in series with the stiffness and damping of the gas film. The design and manufacturing of foil bearings remains costly as it demands of extensive engineering and actual experience. Alternative foil bearing configurations, less costly and easier to manufacture, are highly desirable to enable widespread usage of OFT. This manuscript details the design and manufacturing of a novel Rayleigh-step metal mesh foil thrust bearing (MMFTB) as well as its testing on a dedicated rig. Metal mesh structures offer significant material structural damping and can be easily procured at a fraction of the cost of a typical bump foil strip layer. The MMFTB consists of a solid carrier, a number of stacked annular Copper mesh sheets (wire diameter = 0.25, 0.3 and 0.41 mm), and a steel top foil (0.127 mm thick) that makes six pads (ID = 50.8 mm, OD = 2 ID), each 45° in extent. A 3 μm polymer coats each pad and a photo-chemical process etches a step 20 μm in height. Static and dynamic load measurements (without rotor speed) demonstrate the MMFTB has structural stiffness and material damping similar to that of a publicized bump-type foil thrust bearing. A maiden test of the MMFTB with rotor speed of Ω = 15 krpm (∼80 m/s at bearing outer diameter) proved briefly the bearing operation when applying a tiny thrust load. Further tests with ambient air, a rotor speed of 40 krpm (∼212 m/s at bearing OD), and a very light load/area < 7 kPa failed several of the prototype bearings, all exhibiting significant wear on one or more pads. The source of the failure is the inherent unevenness of the metal mesh stacked substructures, thus causing the pads to bulge towards the rotor collar surface before a load applies. A deficient anchoring method exacerbates the unevenness. Incidentally, a high rotor speed induced large windage that lifted the top foils pushing them against the spinning collar. As the bearing moved towards the rotating collar to begin applying thrust, the local high spots rubbed against the collar, before a hydrodynamic wedge could form to separate the surfaces. Without a robust sacrificial coating, metal-to-metal contact quickly disfigured the contacting top foil pads, erasing the etched step, and leading to failure. In concept, and on paper, the mesh sheets and the top foil lay flat against the bearing carrier, giving a false sense of uniformity in the design process. In actuality, a designer must consider the manufactured states of the individual components and how they assemble. A redesign of the bearing intends to overcome the existing flaws (highlighted herein) by incorporating a thicker top foil that is well anchored (to better withstand the effects of windage), a robust sacrificial coating, and a hydrodynamic wedge accomplished via a circumferential taper on each pad.
- Published
- 2018
8. Multi-Body Contact Dynamics Modeling of Roll Mechanisms in Paper Manufacturing Systems
- Author
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Sirpa Launis, Juha-Matti Kivinen, and Erno Keskinen
- Subjects
Multi body ,Computer science ,Mechanical engineering ,Contact dynamics ,Paper manufacturing - Abstract
A multi-body contact dynamics formulation is introduced to model the dynamic motion of roll mechanisms typical for paper manufacturing systems. Physical contact forces acting on the bodies in the joints are connecting the links of roll mechanisms together instead of purely kinematic constraints used in existing classical algorithms. In a similar way, external contacts between rolls manipulating the paper web are modeled as contact line loads in normal pressing and tangential traction directions. In the case study the loading dynamics of a paper finishing unit used in paper industry has been simulated in order to find out dynamically stable dimensioning for the critical parts in a new four-bar-linkage roll loading mechanism.
- Published
- 2001
9. Retracted: 'Design and Testing Process for a 7kW Radial Inflow Refrigerant Turbine at the University of Queensland' [ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition, Volume 8: Microturbines, Turbochargers and Small Turbomachines; Steam Turbines, Seoul, South Korea, June 13–17, 2016, Conference Sponsors: International Gas Turbine Institute, ISBN: 978-0-7918-4986-6, Copyright © 2016 by ASME. Paper No. GT2016-58111, pp. V008T23A036; 11 pages; doi:10.1115/GT2016-58111]
- Author
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Andrew Rowlands, Hugh Russell, Ingo Jahn, and Carlos Ventura
- Subjects
Stator ,business.industry ,Computer science ,Rotor (electric) ,Mechanical engineering ,Volute ,Modular design ,Rotordynamics ,Turbine ,law.invention ,law ,Turbomachinery ,Design process ,business - Abstract
The Queensland Geothermal Energy Centre of Excellence (QGECE) has been developing a small 7 kW refrigerant radialinflow turbine assembly. Such turbines, when used with organic fluids (e.g. refrigerants), result in power cycles that can have a superior thermodynamic efficiency compared to traditional power cycles and turbines in the low to medium temperature range (100-250°C). The intended use for the UQ 7kW turbine unit is validation of CFD simulations, characterisation of turbomachinery loss mechanisms, and validation of 1-D design methodologies. This paper describes the structural and aerodynamic design process that has led to completion of the turbine unit. The first generation aerodynamic design (rotor and stator) and operating points were selected using the QGECE's 1-D mean line design software TOPGEN, to obtain a simple and robust turbine. Results from preliminary CFD simulations to verify the volute and stator operation and stage simulations to provide design and off-design performance characteristics and structural loads are presented. The turbine assembly was designed with modularity in mind to allow future turbine design iteration. Design information is provided for the overall turbine concept and the modular sub-components, including volute, magnetic coupling, bearing chamber design, shaft rotordynamics, FEA analysis and the instrumentation scheme. The paper concludes with a summary of the planned tests.
- Published
- 2016
10. The State of the Art and Challenges in Geomechanical Modeling of Injector Wells: A Review Paper
- Author
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A. Dahi Taleghani and J. F. Bautista
- Subjects
Engineering ,Petroleum engineering ,Renewable Energy, Sustainability and the Environment ,Process (engineering) ,business.industry ,Mechanical Engineering ,Energy Engineering and Power Technology ,02 engineering and technology ,Injector ,010502 geochemistry & geophysics ,01 natural sciences ,law.invention ,Modeling and simulation ,Wellbore ,Permeability (earth sciences) ,Fuel Technology ,020401 chemical engineering ,Petroleum industry ,Geochemistry and Petrology ,law ,Fracture process ,Fluid injection ,0204 chemical engineering ,business ,0105 earth and related environmental sciences - Abstract
Fluid injection is a common practice in the Oil and Gas industry found in many applications such as waterflooding and disposal of produced fluids. Maintaining high injection rates is crucial to guarantee the economic success of these projects; however, there are geomechanical risks and difficulties involved in this process that may threat the viability of fluid injection projects. Near wellbore reduction of permeability due to pore plugging, formation failure, out of zone injection, sand production, and local compaction are challenging the effectiveness of the injection process. Due to these complications, modeling and simulation has been used as an effective tool to assess injectors’ performance, however, different problems have yet be addressed. In this paper, we review some of these challenges and the solutions that have been proposed as a primary step to understand mechanisms affecting well performance.Copyright © 2016 by ASME
- Published
- 2016
11. Retracted: 'Multi-Objective Aerodynamic Optimisation of a Real Gas Radial-Inflow Turbine' [ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition, Volume 2C: Turbomachinery, Seoul, South Korea, June 13–17, 2016, Conference Sponsors: International Gas Turbine Institute, ISBN: 978-0-7918-4971-2, Copyright © 2016 by ASME. Paper No. GT2016-58132, pp. V02CT45A032; 9 pages; doi:10.1115/GT2016-58132]
- Author
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Kamel Hooman and Emilie Sauret
- Subjects
Gas turbines ,Engineering ,Real gas ,business.industry ,Turbomachinery ,Mechanical engineering ,Aerodynamics ,Inflow ,business ,Turbine ,Marine engineering - Abstract
The above referenced paper has been removed from publication. June 29, 2017. Copyright © 2017 by ASME
- Published
- 2016
12. Retracted: 'The Mechanical Performance of Subarachnoid Space Trabeculae' [ASME 2015 International Mechanical Engineering Congress and Exposition, Volume 3: Biomedical and Biotechnology Engineering, Houston, Texas, USA, November 13–19, 2015, Conference Sponsors: ASME, ISBN: 978-0-7918-5738-0, Copyright © 2015 by ASME. Paper No. IMECE2015-52463, pp. V003T03A092; 3 pages; doi:10.1115/IMECE2015-52463]
- Author
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Asme Asme
- Subjects
Engineering ,business.industry ,Mechanical engineering ,business ,Volume (compression) ,Exposition (narrative) - Abstract
The above referenced paper has been removed from publication. July 5, 2016. Copyright © 2016 by ASME
- Published
- 2015
13. Retracted: 'Using Meta-Models as Fast and Accurate Predictors of a Reconfigurable Mould System' [ASME 2015 International Mechanical Engineering Congress and Exposition, Volume 2B: Advanced Manufacturing, Houston, Texas, USA, November 13–19, 2015, Conference Sponsors: ASME, ISBN: 978-0-7918-5736-6, Copyright © 2015 by ASME. Paper No. IMECE2015-50990, pp. V02BT02A010; 10 pages; doi:10.1115/IMECE2015-50990]
- Author
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Esben Lindgaard and Erik Lund
- Subjects
Engineering ,business.industry ,Advanced manufacturing ,Mechanical engineering ,business ,Exposition (narrative) ,Volume (compression) - Abstract
The above referenced paper has been removed from publication. June 8, 2016. Copyright © 2016 by ASME
- Published
- 2015
14. Conference paper
- Author
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Hans Abrahamsson, Jonathan Mårtensson, Kam Chana, Martin Johansson, and Thomas Povey
- Subjects
geography ,Engineering ,geography.geographical_feature_category ,business.industry ,Mechanical engineering ,HVAC turning vanes ,Aerodynamics ,Inlet ,Turbine ,Vortex ,Heat transfer ,Trailing edge ,Duct (flow) ,business - Abstract
Flow in a turbine duct is highly complex, influenced by the upstream turbine stage flow structures, including tip leakage flow and non-uniformities originating from the upstream HPT vane and rotor. The complexity of the flow makes the prediction using numerical methods difficult, hence there exists a need for experimental validation. This paper presents experimental data including both aerodynamic and heat transfer measurements within an intermediate turbine duct. These have been conducted in the Oxford Turbine Research Facility, a short duration high speed test facility enabling the use of an engine sized turbine, operating at the correct non-dimensional parameters relevant for aerodynamic and heat transfer measurements. The current configuration consists of a HPT stage and a downstream duct including a turning vane, for use in a counter rotating turbine configuration. With a stator-to-stator vane count of 32-to-24, instrumentation was installed on three adjacent intermediate turbine duct vanes and endwalls to investigate its influence. Flow phenomena such as trailing edge wakes and vortex structures from the upstream HPT vane travels through the rotor and forms an inlet condition to the intermediate turbine duct with tangential variations. Time-averaged experimental data show this effect to be distinguishable although varying in the spanwise direction. Comparisons with results from numerical predictions are included to further analyse the flow through the 1.5 stage.Copyright © 2015 by ASME
- Published
- 2015
15. Basic Study on Transient Temperature Response of Papers in a Thermal Transfer Printer
- Author
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Hirotoshi Terao, Takashi Fukue, Risa Ito, Hisashi Hoshino, Koichi Hirose, Tomoko Wauke, and Fumiya Nakagawa
- Subjects
Quality (physics) ,Materials science ,Thermal Head ,Contact resistance ,Thermal ,Mechanical engineering ,Thermal transfer ,Transient (oscillation) ,Thermal printing ,Transient temperature response - Abstract
This study describes temperature response of papers in a thermal transfer printer. Thermal transfer printer produces an image by heating heat sensitive papers using a thermal head. The print quality of the thermal printing is highly dependent on a temperature response of the paper. Our research targets to develop a control technique of temperature of the printing paper to improve the print quality of the thermal transfer printer. In this report, our special attention is paid to investigate the temperature response of a paper when the heat is applied by the thermal head. The temperature transient in the paper is measured while changing the type of the paper. Moreover, in order to investigate a relationship between thermophysical properties of papers and the temperature response, the thermophysical properties are measured. A thermal network analysis is additionally performed and the effects of a contact resistance between the paper and the thermal head are also investigated. It is found that transient temperature response of the printing paper is strongly dependent on a type of the printing paper and the level of an input heat. A change of the temperature response is caused by the difference of thermophysical properties of the paper and a variation of a contact resistance between the paper and the thermal head.
- Published
- 2013
16. Correlation of Cutting Force and Power Consumption for Ultrasonic-Vibration-Assisted Cutting of Label Paper Stacks
- Author
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Sascha Weikert, Jens Boos, Konrad Wegener, and Karl-Robert Deibel
- Subjects
Vibration ,Engineering ,Stack (abstract data type) ,business.industry ,Mechanical engineering ,Drilling ,Structural engineering ,Energy consumption ,Edge (geometry) ,business ,Compression (physics) ,Reduction (mathematics) ,Power (physics) - Abstract
Experiments comparing conventional and ultrasonic vibration assisted guillotine cutting of paper stacks have been performed on plain and aluminum coated label paper. It is shown that ultrasonic vibration assisted cutting reduces the cutting force for both paper species. Reduction of the cutting force allows the down holder force to be decreased and lowers the compression of the paper stack necessary to prevent pull-out of the top sheets of paper. Using a higher amplitude setting on the ultrasonic generator further decreases the cutting force for the paper stack. For three different cutting speeds, it is shown that ultrasonic vibration assisted cutting force reduction depends on the average speed of the tool for both paper species. A linear regression with present experimental data is done to obtain an equation for the relation between input generator power and resulting cutting force. Finally, the quality of the cutting edge is examined, quality parameters are defined, and according to these the cutting edge quality is assessed.
- Published
- 2012
17. Retracted: 'Evaluation of Cam Shaft Profile Form Error by an Electronic Height Gauge' [ASME 2012 International Mechanical Engineering Congress and Exposition, Volume 3: Design, Materials and Manufacturing, Parts A, B, and C, Houston, Texas, USA, November 9-15, 2012, Conference Sponsors: ASME, ISBN: 978-0-7918-4519-6, Copyright © 2012 by ASME. Paper No. IMECE2012-85789, pp. 1481-1486; 6 pages; doi: 10.1115/IMECE2012-85789]
- Author
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Asme Asme
- Subjects
Form error ,Engineering ,Height gauge ,business.industry ,Camshaft ,Mechanical engineering ,business ,Exposition (narrative) ,Volume (compression) - Abstract
The above referenced paper has been removed from publication. April 22, 2015. Copyright© 2015 by ASME
- Published
- 2012
18. Commissioning of a Test Rig for Auto-Ignition Delay Time Measurements on Kerosene Based Fuel Paper
- Author
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J. R. Tilston and W. S. Cheung
- Subjects
Engineering ,Kerosene ,business.industry ,Test rig ,Mechanical engineering ,Injector ,Automotive engineering ,Auto ignition ,law.invention ,Ignition system ,law ,Combustion chamber ,business ,Overheating (electricity) ,Delay time - Abstract
A thorough understanding of the auto-ignition process is critical to the success of lean premixed prevapourised (LPP) combustors for future ultra-low NOx emissions gas turbines. A considerable amount of work has been done in the past on auto-ignition delay time (ADT) measurements for various aviation fuels and hydrocarbons. However, little was known about the influence of various possible fuel additives on ADT. A test rig was designed and built by DERA specifically for ADT measurements. It consisted of an injector housing and an instrumented duct where the ignition location could be monitored by fibre optic sensors. It was intended to acquire ADT measurements at 875K, 16bar and 40m/s of mean flow. The test rig and instrumentation were commissioned in January and February 2000. However, instrumentation inside the injector housing was damaged soon after the initial hot run as a result of overheating. Attempts were made to repair the damaged components and to identify the cause of overheating. Unfortunately, the damage to the components was extensive and the cause of overheating could not be diagnosed. In view of the technical risks involved, it was decided to stop further testing with this rig. Although ADT measurements could not be undertaken as planned, useful operating experience was gained from the tests conducted.Copyright © 2001 by ASME
- Published
- 2001
19. Flutter and Resonant Vibration Characteristics of Engine Blades: An IGTI Scholar Paper
- Author
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A. V. Srinivasan
- Subjects
Gas turbines ,Engineering ,Power station ,business.industry ,media_common.quotation_subject ,Mechanical engineering ,Context (language use) ,Industrial engineering ,Vibration ,Flutter ,Quality (business) ,Product (category theory) ,business ,Reliability (statistics) ,media_common - Abstract
This paper presents an in-depth study of blade vibration problems that seriously impact development of advanced gas turbine configurations. The motivation for this study arises from the author’s conviction that structural integrity of powerplants is the dominant factor that influences the quality, reliability and marketability of the product. Implications of this study in the context of potential R&D challenges and opportunities of interest to industry, governments and academia are discussed.
- Published
- 1997
20. Operating Experience With a 42.5 MW Gas Turbine Used in a Cogeneration Plant at a Paper Mill in the U.S
- Author
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S. T. O’Neill
- Subjects
Gas turbines ,Cogeneration ,Engineering ,Base load power plant ,Waste management ,Combined cycle ,law ,business.industry ,Mechanical engineering ,Paper mill ,Electricity ,business ,law.invention - Abstract
The CW251B10 Gas Turbine has been in service at the Procter & Gamble Paper Mill located at Mehoopany, Pennsylvania since July 1985, and has exhibited outstanding reliability and availability since that time. It operates continuously at base load supplying both electricity and process air for the plant. This paper reviews the operating history of the gas turbine, and describes some of the problems experienced, together with their solutions.Copyright © 1989 by ASME
- Published
- 1989
21. A Comparative Modeling Study of Thermal Mitigation Strategies in Irreversible Electroporation Treatments
- Author
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Kenneth N, Aycock, Sabrina N, Campelo, and Rafael V, Davalos
- Subjects
Mechanics of Materials ,Mechanical Engineering ,General Materials Science ,Condensed Matter Physics ,Research Papers - Abstract
Irreversible electroporation (IRE), also referred to as nonthermal pulsed field ablation (PFA), is an attractive focal ablation modality for solid tumors and cardiac tissue due to its ability to destroy aberrant cells with limited disruption of the underlying tissue architecture. Despite its nonthermal cell death mechanism, application of electrical energy results in Joule heating that, if ignored, can cause undesired thermal injury. Engineered thermal mitigation (TM) technologies including phase change materials (PCMs) and active cooling (AC) have been reported and tested as a potential means to limit thermal damage. However, several variables affect TM performance including the pulsing paradigm, electrode geometry, PCM composition, and chosen active cooling parameters, meaning direct comparisons between approaches are lacking. In this study, we developed a computational model of conventional bipolar and monopolar probes with solid, PCM-filled, or actively cooled cores to simulate clinical IRE treatments in pancreatic tissue. This approach reveals that probes with integrated PCM cores can be tuned to drastically limit thermal damage compared to existing solid probes. Furthermore, actively cooled probes provide additional control over thermal effects within the probe vicinity and can altogether abrogate thermal damage. In practice, such differences in performance must be weighed against the increased time, expense, and effort required for modified probes compared to existing solid probes.
- Published
- 2022
22. Anomalous Nonlinear Dynamics Behavior of Fractional Viscoelastic Beams
- Author
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Maryam Naghibolhosseini, Mohsen Zayernouri, Pegah Varghaei, Jorge L. Suzuki, and Ehsan Kharazmi
- Subjects
Physics ,Steady state ,Applied Mathematics ,Mechanical Engineering ,Equations of motion ,General Medicine ,Mechanics ,Resonance (particle physics) ,Research Papers ,Viscoelasticity ,Stress (mechanics) ,Nonlinear system ,Rheology ,Control and Systems Engineering ,Displacement (fluid) - Abstract
Fractional models and their parameters are sensitive to intrinsic microstructural changes in anomalous materials. We investigate how such physics-informed models propagate the evolving anomalous rheology to the nonlinear dynamics of mechanical systems. In particular, we study the vibration of a fractional, geometrically nonlinear viscoelastic cantilever beam, under base excitation and free vibration, where the viscoelasticity is described by a distributed-order fractional model. We employ Hamilton's principle to obtain the equation of motion with the choice of specific material distribution functions that recover a fractional Kelvin–Voigt viscoelastic model of order α. Through spectral decomposition in space, the resulting time-fractional partial differential equation reduces to a nonlinear time-fractional ordinary differential equation, where the linear counterpart is numerically integrated through a direct L1-difference scheme. We further develop a semi-analytical scheme to solve the nonlinear system through a method of multiple scales, yielding a cubic algebraic equation in terms of the frequency. Our numerical results suggest a set of α-dependent anomalous dynamic qualities, such as far-from-equilibrium power-law decay rates, amplitude super-sensitivity at free vibration, and bifurcation in steady-state amplitude at primary resonance.
- Published
- 2021
23. Analytical and Computational Modeling of Sustained-Release Drug Implants in the Vitreous Humor
- Author
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Mark S. Humayun, Anita Penkova, Satwindar Singh Sadhal, Amin Naghdloo, and Anahid Khoobyar
- Subjects
Sustained release drug ,Mechanics of Materials ,business.industry ,Mechanical Engineering ,Medicine ,General Materials Science ,Condensed Matter Physics ,business ,Research Papers ,Biomedical engineering - Abstract
Sustained ocular drug delivery systems are necessary for patients needing regular drug therapy since frequent injection is painful, undesirable, and risky. One type of sustained-release systems includes pellets loaded with the drug, encapsulated in a porous shell that can be injected into the vitreous humor. There the released drug diffuses while the physiological flow of water provides the convective transport. The fluid flow within the vitreous is described by Darcy's equations for the analytical model and Brinkman flow for the computational analysis while the drug transport is given by the classical convection–diffusion equation. Since the timescale for the drug depletion is quite large, for the analytical model, we consider the exterior surrounding the capsule to be quasi-steady and the interior is time dependent. In the vitreous, the fluid-flow process is relatively slow, and meaningful results can be obtained for small Peclet number whereby a perturbation analysis is possible. For an isolated capsule, with approximately uniform flow in the far field around it, the mass-transfer problem requires singular perturbation with inner and outer matching. The computational model, besides accommodating the ocular geometry, allows for a fully time-dependent mass-concentration solution and also admits moderate Peclet numbers. As expected, the release rate diminishes with time as the drug depletion lowers the driving potential. The predictive results are sufficient general for a range of capsule permeability values and are useful for the design of the sustained-release microspheres as to the requisite permeability for specific drugs.
- Published
- 2021
24. Design Equations for Mixed-Mode Fracture of Dental Ceramic–Cement Interfaces Using the Brazil-Nut-Sandwich Test
- Author
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Renata Marques de Melo, David Tamim Manan, Jeong-Ho Kim, Yu Zhang, University of Connecticut, Universidade Estadual Paulista (UNESP), and University of Pennsylvania
- Subjects
Materials science ,their composites ,interfacial fracture ,metals ,composite resin cements ,finite element analysis ,02 engineering and technology ,ceramics ,fracture toughness ,Stress (mechanics) ,Brazil-nut-sandwich test ,03 medical and health sciences ,0302 clinical medicine ,Fracture toughness ,food ,0203 mechanical engineering ,General Materials Science ,Mixed mode fracture ,intermetallics ,stress intensity factors ,Fracture process ,Ceramic ,Composite material ,polymers ,Cement ,Mechanical Engineering ,030206 dentistry ,Condensed Matter Physics ,Research Papers ,elastic behavior ,Finite element method ,food.food ,020303 mechanical engineering & transports ,Mechanics of Materials ,visual_art ,mechanical behavior ,visual_art.visual_art_medium ,ceramic restorations ,Brazil nut - Abstract
Made available in DSpace on 2022-04-29T08:41:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-10-01 Dental interfaces are subject to mixed-mode loading. This study provides practical guidance for determining interfacial fracture toughness of dental ceramic systems. We address interfacial fracture of a composite resin cement sandwiched between two dental ceramic materials. Emphasis is placed on sandwich disc specimens with cracks originating from elliptical-shaped flaws near the center, for which analytical fracture mechanics methods fail to predict. The interaction integral method is used to provide accurate finite element solutions for cracks with elliptical-shaped flaws in a Brazil-nut-sandwich specimen. The developed model was first validated with existing experimental data and then used to evaluate the three most widely used dental ceramic systems: polycrystalline ceramics (zirconia), glass-ceramics (lithium disilicate), and feldspathic ceramics (porcelain). Contrary to disc specimens with ideal cracks, those with cracks emanating from elliptical-shaped flaws do not exhibit a monotonic increase in interfacial toughness. Also, interfacial fracture toughness is seen to have a direct relationship with the aspect ratio of elliptical-shaped flaws and an inverse relationship with the modulus ratio of the constituents. The presence of an elliptical-shaped flaw significantly changes the interfacial fracture behavior of sandwich structures. Semi-empirical design equations are provided for fracture toughness and stress intensity factors for interfacial cracks. The developed design equations provide practical guidance for determining interfacial fracture toughness of selected dental ceramic material systems. Those equations take into account four critical factors: size of the elliptical flaw, modulus ratio of constituent materials, loading angle, and applied load. Department of Civil and Environmental Engineering University of Connecticut, 261 Glenbrook Road, U-3037 Department of Dental Materials and Prosthodontics Institute of Science and Technology of Sao Jose dos Campos Sao Paulo State University (UNESP), SP Department of Preventive and Restorative Sciences School of Dental Medicine University of Pennsylvania Department of Dental Materials and Prosthodontics Institute of Science and Technology of Sao Jose dos Campos Sao Paulo State University (UNESP), SP
- Published
- 2021
25. Proper Orthogonal Decomposition-Based Method for Predicting Flow and Heat Transfer of Oil and Water in Reservoir
- Author
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Xianhang Sun, Ma Xu, Pan Yi, Bingfan Li, Weiqiu Huang, and Yang Shuangchun
- Subjects
0303 health sciences ,Renewable Energy, Sustainability and the Environment ,020209 energy ,Mechanical Engineering ,Flow (psychology) ,Physical system ,Finite difference method ,Energy Engineering and Power Technology ,Basis function ,02 engineering and technology ,Mechanics ,Research Papers ,03 medical and health sciences ,Fuel Technology ,Point of delivery ,Geochemistry and Petrology ,Principal component analysis ,Heat transfer ,Reservoir engineering ,0202 electrical engineering, electronic engineering, information engineering ,030304 developmental biology ,Mathematics - Abstract
Calculation process of some reservoir engineering problems involves several passes of full-order numerical reservoir simulations, and this makes it a time-consuming process. In this study, a fast method based on proper orthogonal decomposition (POD) was developed to predict flow and heat transfer of oil and water in a reservoir. The reduced order model for flow and heat transfer of oil and water in the hot water-drive reservoir was generated. Then, POD was used to extract a reduced set of POD basis functions from a series of “snapshots” obtained by a finite difference method (FDM), and these POD basis functions most efficiently represent the dynamic characteristics of the original physical system. After injection and production parameters are changed constantly, the POD basis functions combined with the reduced order model were used to predict the new physical fields. The POD-based method was approved on a two-dimensional hot water-drive reservoir model. For the example of this paper, compared with FDM, the prediction error of water saturation and temperature fields were less than 1.3% and 1.5%, respectively; what is more, it was quite fast, where the increase in calculation speed was more than 70 times.
- Published
- 2019
26. Dual functions of insect wings in an odor-guided aeronautic navigation
- Author
-
Kai Zhao, Chengyu Li, and Haibo Dong
- Subjects
Physics ,Lift coefficient ,Wing ,animal structures ,Mechanical Engineering ,Acoustics ,fungi ,Olfaction ,Aerodynamics ,01 natural sciences ,010305 fluids & plasmas ,Vortex ,Lift (force) ,Odor ,Photogallery Papers ,0103 physical sciences ,Flapping ,010306 general physics - Abstract
Insects can detect and locate distant odor sources (food, mate, etc.) by tracking odor plumes, which is key to their survival. During an odor-guided navigation, flapping wings have been speculated to actively draw odorants to the antennae and enhance olfactory sensitivity. Utilizing an in-house computational fluid dynamics solver, we have quantified the odor plume structures of a fruit fly in a forward flight motion and have confirmed that the flapping wings induce a strong vortex flow over the insect's head, thereby enhancing the odor mass flux around the antennae (by ~1.8 times). To further understand the function of different wing area in terms of aerodynamics and olfaction, we designed an altered fruit fly wing by removing its trailing-edge portion; subsequent simulations showed that this altered wing has an improved lift production but with significantly reduction of the induced odor mass flux. Contrary to the common belief that the wing shapes of an insect are optimized only for aerodynamic performance, our results suggest that, because both aerodynamic and olfactory functions are indispensable during the odor-guided navigation, insects may sacrifice some aerodynamic potential to enhance olfactory detection; and the shape and size of the wing may be a balance between the two functions. Furthermore, we found that higher wing beat frequency and wing reversal phase induce higher odor mass flux, while lower beat frequency and downstroke phase produce better lift coefficient, which indicates another balance between the two functions.
- Published
- 2020
27. Pneumatic Variable Series Elastic Actuator
- Author
-
Molei Wu, Xiangrong Shen, and Hao Zheng
- Subjects
0209 industrial biotechnology ,Engineering ,Plant ,02 engineering and technology ,Computer Science::Robotics ,03 medical and health sciences ,020901 industrial engineering & automation ,0302 clinical medicine ,Motor controller ,Control theory ,medicine ,Instrumentation ,Equilibrium point ,Pneumatic actuator ,business.industry ,Pressure control ,Mechanical Engineering ,Motor control ,Stiffness ,Control engineering ,Research Papers ,Computer Science Applications ,Control and Systems Engineering ,medicine.symptom ,business ,Actuator ,030217 neurology & neurosurgery ,Information Systems - Abstract
Inspired by human motor control theory, stiffness control is highly effective in manipulation and human-interactive tasks. The implementation of stiffness control in robotic systems, however, has largely been limited to closed-loop control, and suffers from multiple issues such as limited frequency range, potential instability, and lack of contribution to energy efficiency. Variable-stiffness actuator represents a better solution, but the current designs are complex, heavy, and bulky. The approach in this paper seeks to address these issues by using pneumatic actuator as a variable series elastic actuator (VSEA), leveraging the compressibility of the working fluid. In this work, a pneumatic actuator is modeled as an elastic element with controllable stiffness and equilibrium point, both of which are functions of air masses in the two chambers. As such, for the implementation of stiffness control in a robotic system, the desired stiffness/equilibrium point can be converted to the desired chamber air masses, and a predictive pressure control approach is developed to control the timing of valve switching to obtain the desired air mass while minimizing control action. Experimental results showed that the new approach in this paper requires less expensive hardware (on–off valve instead of proportional valve), causes less control action in implementation, and provides good control performance by leveraging the inherent dynamics of the actuator.
- Published
- 2016
28. Model Consistency for Mechanical Design: Bridging Lumped and Distributed Parameter Models With a Priori Guarantees.
- Author
-
Wang, Randi, Shapiro, Vadim, and Mehandish, Morad
- Subjects
- *
MECHANICAL models , *ENGINEERING design , *MECHANICAL engineering , *MECHANICAL engineers - Abstract
Engineering design often involves representation in at least two levels of abstraction: the system-level, represented by lumped parameter models (LPMs), and the geometric-level, represented by distributed parameter models (DPMs). Functional design innovation commonly occurs at the system-level, followed by a geometric-level realization of functional LPM components. However, comparing these two levels in terms of behavioral outcomes can be challenging and time-consuming, leading to delays in design translations between system and mechanical engineers. In this paper, we propose a simulation-free scheme that compares LPMs and spatially discretized DPMs based on their model specifications and behaviors of interest, regardless of modeling languages and numerical methods. We adopt a model order reduction (MOR) technique that a priori guarantees accuracy, stability, and convergence to improve the computational efficiency of large-scale models. Our approach is demonstrated through the model consistency analysis of several mechanical designs, showing its validity, efficiency, and generality. Our method provides a systematic way to compare system-level and geometric-level designs, improving reliability and facilitating design translation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. Predicting the Force Needed to Create a Compression Seal in an Ultrathin Elastoviscoplastic Membrane
- Author
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Patrick S. McNeff and Brian K. Paul
- Subjects
Materials science ,Microchannel ,Process Chemistry and Technology ,010401 analytical chemistry ,030232 urology & nephrology ,Mechanical engineering ,Compression (physics) ,01 natural sciences ,Seal (mechanical) ,Research Papers ,Industrial and Manufacturing Engineering ,Finite element method ,0104 chemical sciences ,03 medical and health sciences ,0302 clinical medicine ,Membrane ,Boss ,Mechanics of Materials ,Approximation error ,visual_art ,visual_art.visual_art_medium ,Composite material ,Polycarbonate - Abstract
In this paper, a finite element model is developed, and experimentally validated, for predicting the force required to produce a compression seal between a polycarbonate sealing boss and a 25 μm thick elastoviscoplastic hemodialysis membrane. This work leverages previous efforts to determine the conditions for hermetic sealing in a microchannel hemodialyser fabricated using hot-embossed polycarbonate microchannel laminae containing sealing boss features. Methods are developed for mechanically characterizing the thin elastoviscoplastic hemodialysis membrane. Experimental data for assessing the depth of penetration into the membrane as a function of force show an R2 value of 0.85 showing good repeatability. The average percent error was found to be −8.0% with a range between −21.9% and 4.4% error in the strain region of interest.Copyright © 2016 by ASME
- Published
- 2017
30. Design of Stretchable Electronics Against Impact
- Author
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John A. Rogers, Xue Feng, Matt Pharr, Yonggang Huang, and Jianghong Yuan
- Subjects
Materials science ,Mechanical Engineering ,Analytic model ,Stretchable electronics ,Nanotechnology ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Biocompatible material ,Research Papers ,Viscoelasticity ,Encapsulation (networking) ,chemistry.chemical_compound ,020303 mechanical engineering & transports ,Silicone ,0203 mechanical engineering ,chemistry ,Resist ,Mechanics of Materials ,0210 nano-technology ,Device failure - Abstract
Stretchable electronics offer soft, biocompatible mechanical properties; these same properties make them susceptible to device failure associated with physical impact. This paper studies designs for stretchable electronics that resist failure from impacts due to incorporation of a viscoelastic encapsulation layer. Results indicate that the impact resistance depends on the thickness and viscoelastic properties of the encapsulation layer, as well as the duration of impact. An analytic model for the critical thickness of the encapsulation layer is established. It is shown that a commercially available, low modulus silicone material offers viscous properties that make it a good candidate as the encapsulation layer for stretchable electronics.
- Published
- 2016
31. Wrinkling of Tympanic Membrane Under Unbalanced Pressure
- Author
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Shuodao Wang, Siyuan Bao, Bo Wang, Pravarsha Ghanta, Junfeng Liang, Hongbing Lu, and Sandra Vinnikova
- Subjects
Materials science ,Atmospheric pressure ,Mechanical Engineering ,02 engineering and technology ,Deformation (meteorology) ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Acoustic transmission ,Research Papers ,Finite element method ,020303 mechanical engineering & transports ,medicine.anatomical_structure ,Membrane ,0203 mechanical engineering ,Mechanics of Materials ,Normal mode ,Middle ear ,medicine ,otorhinolaryngologic diseases ,sense organs ,Composite material ,0210 nano-technology - Abstract
Mechanics of tympanic membrane (TM) is crucial for investigating the acoustic transmission through the ear. In this study, we studied the wrinkling behavior of tympanic membrane when it is exposed to mismatched air pressure between the ambient and the middle ear. The Rayleigh–Ritz method is adopted to analyze the critical wrinkling pressure and the fundamental eigenmode. An approximate analytical solution is obtained and validated by finite element analysis (FEA). The model will be useful in future investigations on how the wrinkling deformation of the TM alters the acoustic transmission function of the ear.
- Published
- 2017
32. Modeling of Interior Ballistic Gas-Solid Flow Using a Coupled Computational Fluid Dynamics-Discrete Element Method
- Author
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Cheng Cheng and Xiaobing Zhang
- Subjects
Physics ,Finite volume method ,Discretization ,business.industry ,Mechanical Engineering ,Mechanics ,Computational fluid dynamics ,Condensed Matter Physics ,Collision ,Research Papers ,Discrete element method ,Classical mechanics ,AUSM ,Mechanics of Materials ,Drag ,business ,CFD-DEM - Abstract
In conventional models for two-phase reactive flow of interior ballistic, the dynamic collision phenomenon of particles is neglected or empirically simplified. However, the particle collision between particles may play an important role in dilute two-phase flow because the distribution of particles is extremely nonuniform. The collision force may be one of the key factors to influence the particle movement. This paper presents the CFD-DEM approach for simulation of interior ballistic two-phase flow considering the dynamic collision process. The gas phase is treated as a Eulerian continuum and described by a computational fluid dynamic method (CFD). The solid phase is modeled by discrete element method (DEM) using a soft sphere approach for the particle collision dynamic. The model takes into account grain combustion, particle-particle collisions, particle-wall collisions, interphase drag and heat transfer between gas and solid phases. The continuous gas phase equations are discretized in finite volume form and solved by the AUSM+-up scheme with the higher order accurate reconstruction method. Translational and rotational motions of discrete particles are solved by explicit time integrations. The direct mapping contact detection algorithm is used. The multigrid method is applied in the void fraction calculation, the contact detection procedure, and CFD solving procedure. Several verification tests demonstrate the accuracy and reliability of this approach. The simulation of an experimental igniter device in open air shows good agreement between the model and experimental measurements. This paper has implications for improving the ability to capture the complex physics phenomena of two-phase flow during the interior ballistic cycle and to predict dynamic collision phenomena at the individual particle scale.
- Published
- 2013
33. Design of Revolute Joints for In-Mold Assembly Using Insert Molding
- Author
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Leicester Ehrlich, Satyandra K. Gupta, Jaydev P. Desai, and Arvind Ananthanarayanan
- Subjects
Engineering ,Insert (composites) ,business.industry ,Medical robot ,Mechanical Engineering ,Process (computing) ,Mechanical engineering ,Molding (process) ,Revolute joint ,Computer Graphics and Computer-Aided Design ,Research Papers ,Computer Science Applications ,Mechanics of Materials ,Robot ,Torque ,business ,Joint (geology) - Abstract
Creating highly articulated miniature structures requires assembling a large number of small parts. This is a very challenging task and increases cost of mechanical assemblies. Insert molding presents the possibility of creating a highly articulated structure in a single molding step. This can be accomplished by placing multiple metallic bearings in the mold and injecting plastic on top of them. In theory, this idea can generate a multi degree of freedom structures in just one processing step without requiring any post molding assembly operations. However, the polymer material has a tendency to shrink on top of the metal bearings and hence jam the joints. Hence, until now insert molding has not been used to create articulated structures. This paper presents a theoretical model for estimating the extent of joint jamming that occurs due to the shrinkage of the polymer on top of the metal bearings. The level of joint jamming is seen as the effective torque needed to overcome the friction in the revolute joints formed by insert molding. We then use this model to select the optimum design parameters which can be used to fabricate functional, highly articulating assemblies while meeting manufacturing constraints. Our analysis shows that the strength of weld-lines formed during the in-mold assembly process play a significant role in determining the minimum joint dimensions necessary for fabricating functional revolute joints. We have used the models and methods described in this paper to successfully fabricate the structure for a minimally invasive medical robot prototype with potential applications in neurosurgery. To the best of our knowledge, this is the first demonstration of building an articulated structure with multiple degrees of freedom using insert molding.
- Published
- 2011
34. An Anisotropic Multiphysics Model for Intervertebral Disk
- Author
-
Xin Gao, Qiaoqiao Zhu, and Weiyong Gu
- Subjects
Materials science ,Mechanical Engineering ,Multiphysics ,0206 medical engineering ,Torsion (mechanics) ,02 engineering and technology ,Mechanics ,Condensed Matter Physics ,020601 biomedical engineering ,Research Papers ,Mixture theory ,03 medical and health sciences ,Intervertebral disk ,Nonlinear system ,Mechanobiology ,0302 clinical medicine ,Classical mechanics ,Mechanics of Materials ,Anisotropic permeability ,Anisotropy ,030217 neurology & neurosurgery - Abstract
Intervertebral disk (IVD) is the largest avascular structure in human body, consisting of three types of charged hydrated soft tissues. Its mechanical behavior is nonlinear and anisotropic, due mainly to nonlinear interactions among different constituents within tissues. In this study, a more realistic anisotropic multiphysics model was developed based on the continuum mixture theory and employed to characterize the couplings of multiple physical fields in the IVD. Numerical simulations demonstrate that this model is capable of systematically predicting the mechanical and electrochemical signals within the disk under various loading conditions, which is essential in understanding the mechanobiology of IVD.
- Published
- 2015
35. Solution of Inverse Kinematics for 6R Robot Manipulators With Offset Wrist Based on Geometric Algebra
- Author
-
Zhen Yang, Wenyu Yang, and Zhongtao Fu
- Subjects
Computer Science::Robotics ,Nonlinear system ,Robot kinematics ,Geometric algebra ,Robot calibration ,Inverse kinematics ,Control theory ,Kinematics equations ,Computer science ,Mechanical Engineering ,Robot ,Kinematics ,Research Papers - Abstract
In this paper, we present an efficient method based on geometric algebra for computing the solutions to the inverse kinematics problem (IKP) of the 6R robot manipulators with offset wrist. Due to the fact that there exist some difficulties to solve the inverse kinematics problem when the kinematics equations are complex, highly nonlinear, coupled and multiple solutions in terms of these robot manipulators stated mathematically, we apply the theory of Geometric Algebra to the kinematic modeling of 6R robot manipulators simply and generate closed-form kinematics equations, reformulate the problem as a generalized eigenvalue problem with symbolic elimination technique, and then yield 16 solutions. Finally, a spray painting robot, which conforms to the type of robot manipulators, is used as an example of implementation for the effectiveness and real-time of this method. The experimental results show that this method has a large advantage over the classical methods on geometric intuition, computation and real-time, and can be directly extended to all serial robot manipulators and completely automatized, which provides a new tool on the analysis and application of general robot manipulators.
- Published
- 2013
36. A Nondestructive Evaluation Method: Measuring the Fixed Strength of Spot-Welded Joint Points by Surface Electrical Resistivity
- Author
-
Hirofumi Inoue, Natsuko Ike, Sung-Mo Yang, Keitaro Yamashita, Masahiro Iwata, and Akira Shimamoto
- Subjects
Materials science ,Structural material ,business.industry ,Mechanical Engineering ,Welding ,Structural engineering ,Research Papers ,law.invention ,Electrical resistance and conductance ,Mechanics of Materials ,law ,Electrical resistivity and conductivity ,Nondestructive testing ,Ultimate tensile strength ,Shear strength ,Composite material ,Safety, Risk, Reliability and Quality ,business ,Joint (geology) - Abstract
Destructive tests are generally applied to evaluate the fixed strength of spot-welding nuggets of zinc-plated steel (which is a widely used primary structural material for automobiles). These destructive tests, however, are expensive and time-consuming. This paper proposes a nondestructive method for evaluating the fixed strength of the welded joints using surface electrical resistance. A direct current nugget-tester and probes have been developed by the authors for this purpose. The proposed nondestructive method uses the relative decrease in surface electrical resistance, α. The proposed method also considers the effect of the corona bond. The nugget diameter is estimated by two factors: RQuota, which is calculated from variation of resistance, and a constant that represents the area of the corona bond. Since the maximum tensile strength is correlated with the nugget diameter, it can be inferred from the estimated nugget diameter. When appropriate measuring conditions for the surface electrical resistance are chosen, the proposed method can effectively evaluate the fixed strength of the spot-welded joints even if the steel sheet is zinc-plated.
- Published
- 2013
37. Enhancing Low Temperature Combustion With Biodiesel Blending in a Diesel Engine at a Medium Load Condition
- Author
-
Jung Hwan Kim, Seungmook Oh, Duksang Kim, and Sunyoup Lee
- Subjects
Biodiesel ,Diesel exhaust ,Diesel particulate filter ,Materials science ,Waste management ,Mechanical Engineering ,food and beverages ,Energy Engineering and Power Technology ,Aerospace Engineering ,Diesel cycle ,Pulp and paper industry ,Diesel engine ,complex mixtures ,Diesel fuel ,Fuel Technology ,Nuclear Energy and Engineering ,Mean effective pressure ,NOx - Abstract
The present study investigated the effects of biodiesel blending under a wide range of intake oxygen concentration levels in a diesel engine. This study attempted to identify the lowest biodiesel blending rate that achieves acceptable levels of nitric oxides (NOx), soot, and coefficient of variation in the indicated mean effective pressure (COVIMEP). Biodiesel blending was to be minimized in order to reduce the fuel penalty associated with the biodiesels lower caloric value. Engine experiments were performed in a 1-liter single-cylinder diesel engine at an engine speed of 1400 rev/min under a medium load condition. The blend rate and intake oxygen concentration were varied independently of each other at a constant intake pressure of 200 kPa. The biodiesel blend rate varied from 0% (B000) to 100% biodiesel (B100) at a 20% increment. The intake oxygen level was adjusted from 8 to 19% by volume (vol %) in order to embrace both conventional and low-temperature combustion (LTC) operations. A fixed injection duration of 788 μs at a fuel rail pressure of 160 MPa exhibited a gross indicated mean effective pressure (IMEP) between 750 kPa and 910 kPa, depending on the intake oxygen concentration. The experimental results indicated that the intake oxygen level had to be below 10 vol% to achieve the indicated specific NOx (ISNOx) below 0.2g/kWhr with the B000 fuel. However, a substantial soot increase was exhibited at such a low intake oxygen level. Biodiesel blending reduced NOx until the blending rate reached 60% with reduced in-cylinder temperature due to lower total energy release. As a result, 60%-biodiesel blended diesel (B060) achieved NOx, soot, and COVIMEP of 0.2 g/kWhr, 0.37 filter smoke number (FSN), and 0.5, respectively, at an intake oxygen concentration of 14 vol%. The corresponding indicated thermal efficiency was 43.2%.
- Published
- 2014
38. Fabrication of Y2O3-Doped Zirconia/Gadolinia-Doped Ceria Bilayer Electrolyte Thin Film SOFC Cells of SOFCs by Single-Pulsed Laser Deposition Processing
- Author
-
H. Ishibashi, Motoaki Adachi, S. Yamaguchi, T. Mukai, Shigeki Tsukui, K.C. Goretta, Yoshiharu Kakehi, Tadaoki Kusaka, Ken-ichi Yoshida, R. Hatayama, and Kazuo Satoh
- Subjects
Materials science ,Renewable Energy, Sustainability and the Environment ,Mechanical Engineering ,Bilayer ,Energy Engineering and Power Technology ,Mineralogy ,Cathode ,Electronic, Optical and Magnetic Materials ,law.invention ,Anode ,Pulsed laser deposition ,Crystallinity ,Mechanics of Materials ,law ,Solid oxide fuel cell ,Thin film ,Composite material ,Yttria-stabilized zirconia ,Research Paper - Abstract
An 8 -mol. % Y2O3-doped zirconia/10-mol. % GdO2-doped ceria (YSZ/GDC) bilayer electrolyte and a Gd0.5Sr0.5CoO3 (GSCO) cathode were deposited by a single-processing, pulsed laser deposition (PLD) method to fabricate anode support cells. No additional heat treatment was needed. Laser frequencies of 10, 20, and 100 Hz were used to deposit bilayer electrolytes between the NiO–YSZ (NiO:YSZ = 60:40 wt. %) anode substrate and the GSCO cathode thin film. The GDC thin film produced at 10 Hz was smooth, well-crystallized, and highly dense. The crystallinity of the GSCO cathode on the GDC was also improved. We concluded the GDC crystallinity affected the crystallinity of the cathode thin film. The resistivity of the YSZ single layer (5.7 μm thickness) was 1.4 times higher than that of the YSZ/GDC bilayer (YSZ 3.0 μm thickness, GDC 2.7 μm thickness) at 600 °C and that of the YSZ-GDC interface became low. The optimum YSZ thickness was found to be approximately 3.0 μm, at which thickness there was effective blocking of the passage of hydrogen molecules and electrons. A cell with a YSZ (3.0 μm thickness, fabricated at 20 Hz)/GDC (5.0 μm thickness, fabricated at 10 Hz) bilayer and GSCO cathode thin film exhibited a maximum power density of 400 mW·cm–2 at a comparatively low temperature of 600 °C.
- Published
- 2013
39. Long-Term Stability of Residual Stress Improvement by Water Jet Peening Considering Working Processes
- Author
-
Masahito Mochizuki, Shinsuke Itoh, Tadafumi Hashimoto, Yusuke Osawa, and Kazutoshi Nishimoto
- Subjects
Materials science ,Mechanical Engineering ,Metallurgy ,Peening ,Welding ,Shot peening ,Research Papers ,law.invention ,Stress (mechanics) ,Creep ,Mechanics of Materials ,Residual stress ,law ,Stress relaxation ,Composite material ,Stress corrosion cracking ,Safety, Risk, Reliability and Quality - Abstract
To prevent primary water stress corrosion cracking (PWSCC), water jet peening (WJP) has been used on the welds of Ni-based alloys in pressurized water reactors (PWRs). Before WJP, the welds are machined and buffed in order to conduct a penetrant test (PT) to verify the weld qualities to access, and microstructure evolution takes place in the target area due to the severe plastic deformation. The compressive residual stresses induced by WJP might be unstable under elevated temperatures because of the high dislocation density in the compressive stress layer. Therefore, the stability of the compressive residual stresses caused by WJP was investigated during long-term operation by considering the microstructure evolution due to the working processes. The following conclusions were made: The compressive residual stresses were slightly relaxed in the surface layers of the thermally aged specimens. There were no differences in the magnitude of the relaxation based on temperature or time. The compressive residual stresses induced by WJP were confirmed to remain stable under elevated temperatures. The stress relaxation at the surface followed the Johnson–Mehl equation, which states that stress relaxation can occur due to the recovery of severe plastic strain, since the estimated activation energy agrees very well with the self-diffusion energy for Ni. By utilizing the additivity rule, it was indicated that stress relaxation due to recovery is completed during the startup process. It was proposed that the long-term stability of WJP under elevated temperatures must be assessed based on compressive stresses with respect to the yield stress. Thermal elastic–plastic creep analysis was performed to predict the effect of creep strain. After 100 yr of simulated continuous operation at 80% capacity, there was little change in the WJP compressive stresses under an actual operating temperature of 623 K. Therefore, the long-term stability of WJP during actual operation was analytically predicted.
- Published
- 2013
40. Sensitivity Analysis of Fitness-For-Service Assessment Based on Reliability for Cylindrical Pressure Vessels With Local Metal Loss
- Author
-
Shinsuke Sakai, Takuyo Kaida, and Satoshi Izumi
- Subjects
Engineering ,business.industry ,Stochastic process ,Mechanical Engineering ,Failure probability ,Structural integrity ,Research Papers ,Pressure vessel ,Reliability engineering ,Mechanics of Materials ,Forensic engineering ,Limit state design ,Sensitivity (control systems) ,Safety, Risk, Reliability and Quality ,business ,Constant (mathematics) ,Reliability (statistics) - Abstract
The concern with Fitness-For-Service (FFS) assessment using stochastic analysis for aged pressure equipments with local metal loss has been growing for the last several years. The structural integrity assessment based on reliability helps to make a decision as to whether to run or repair the equipments with local metal loss. As for analysis of failure probability, it is important to clear which variables affect highly the structural integrity. The stochastic property of the influential parameter needs to be clarified. There has, however, been little study to analyze quantitatively the sensitivity of the parameters for the FFS assessment of the components with local metal loss. In this study, the effects of parameters on plastic collapse of the damaged component were evaluated utilizing parameter sensitivity study. Additionally, sensitivity indices for the component with several shapes of local metal loss were analyzed. It was found from the results that the corrosion rate has much influence on probability of failure. Finally, practical stochastic analysis procedure for the component with local metal loss was proposed. In the proposed procedure, the parameter which has consistently low sensitivity to limit state was used as constant value.
- Published
- 2012
41. Flow and Particle Dispersion in Lung Acini: Effect of Geometric and Dynamic Parameters During Synchronous Ventilation
- Author
-
Sudhaker Chhabra and Ajay K. Prasad
- Subjects
Flow visualization ,Flow (psychology) ,Physics::Medical Physics ,Nanotechnology ,Pipe flow ,lung ,flow visualisation ,pattern formation ,particle transport ,generation ,pneumodynamics ,alveolus ,Physics ,fluid oscillations ,Mechanical Engineering ,ventilation ,flow patterns ,inhalable therapeutics ,Mechanics ,lung acini ,Research Papers ,Symmetry (physics) ,toxicological ,pipe flow ,Particle image velocimetry ,Flow velocity ,particle deposition ,bifurcation ,Particle ,Particle deposition - Abstract
The human lung comprises about 300 million alveoli which are located on bronchioles between the 17th to 24th generations of the acinar tree, with a progressively higher population density in the deeper branches (lower acini). The alveolar size and aspect ratio change with generation number. Due to successive bifurcation, the flow velocity magnitude also decreases as the bronchiole diameter decreases from the upper to lower acini. As a result, fluid dynamic parameters such as Reynolds (Re) and Womersley (α) numbers progressively decrease with increasing generation number. In order to characterize alveolar flow patterns and inhaled particle transport during synchronous ventilation, we have conducted measurements for a range of dimensionless parameters physiologically relevant to the upper acini. Acinar airflow patterns were measured using a simplified in vitro alveolar model consisting of a single transparent elastic truncated sphere (representing the alveolus) mounted over a circular hole on the side of a rigid circular tube (representing the bronchiole). The model alveolus was capable of expanding and contracting in-phase with the oscillatory flow through the bronchiole thereby simulating synchronous ventilation. Realistic breathing conditions were achieved by exercising the model over a range of progressively varying geometric and dynamic parameters to simulate the environment within several generations of the acinar tree. Particle image velocimetry was used to measure the resulting flow patterns. Next, we used the measured flow fields to calculate particle trajectories to obtain particle transport and deposition statistics for massless and finite-size particles under the influence of flow advection and gravity. Our study shows that the geometric parameters (β and ΔV/V) primarily affect the velocity magnitudes, whereas the dynamic parameters (Re and α) distort the flow symmetry while also altering the velocity magnitudes. Consequently, the dynamic parameters have a greater influence on the particle trajectories and deposition statistics compared to the geometric parameters. The results from this study can benefit pulmonary research into the risk assessment of toxicological inhaled aerosols, and the pharmaceutical industry by providing better insight into the flow patterns and particle transport of inhalable therapeutics in the acini.
- Published
- 2011
42. Jubilee Review: The 65 Years of the ASME Machine Design Award (1958-2023).
- Author
-
Huijuan Feng, Guanglu Jia, Yenhua Lin, and Dai, Jian S.
- Subjects
- *
MACHINE design , *DESIGN awards , *ENGINEERING design , *MECHANICAL engineering , *AWARDS - Abstract
As the most prestigious award in the field of machine design, the ASME Machine Design Award relishes its prestige and prominence. In the past 65 years since its inception in 1958, 60 eminent scholars have received this honor. This paper reviews the history of this prestigious award, including a summary of the contributions to the field of all 60 recipients, and acts as an archival document. Reviewing these awards in the past 65 years by following the tracks of its recipients elucidates developments in the field and significant contributions to the advancement of knowledge in machine design. In particular, novel contributions and remarkable achievements in the fields of mechanical engineering and machine design and development are recorded. This should be of interest to those interested in the study and in the historical development of mechanical engineering, particularly in machine design. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
43. Arthur Lubinski Best ASME Mechanical Engineering Paper presented at OTC -- 2014.
- Subjects
MATERIAL fatigue ,MECHANICAL engineering - Abstract
An abstract of the mechanical engineering paper, titled "Subsea Wellhead and Riser Fatigue Monitoring in a Strong Surface and Submerged Current Environment," presented by Arthur Lubinski at the 2014 Offshore Technology Conference (OTC) is presented.
- Published
- 2014
44. 2015 Lubinski Paper Nominees.
- Subjects
PETROLEUM industry ,MECHANICAL engineering ,AWARDS ,SOCIETIES - Abstract
A list of the nominees to the 2015 Lubinski Paper Awards conferred by the Petroleum Division of the mechanical engineering society ASME is presented.
- Published
- 2015
45. A BETTER BLADDER ROBOT: With joints, tendons, and more, this slim robot can achieve 3D positions inside the bladder for accurate diagnoses.
- Author
-
CUBARRUBIA, EYDIE
- Subjects
TENDONS ,MEDICAL sciences ,ROBOTS ,TENDONS (Prestressed concrete) ,BLADDER ,AEROSPACE engineering ,MECHANICAL engineering - Abstract
The article focuses on researchers at the University of Texas at Arlington developing a microbot system for diagnosing bladder diseases more effectively, outlined in a paper titled "A Microbot With an Attached Microforce Sensor for Transurethral Access to the Bladder Interior Wall." It mentions the system, equipped with a microforce sensor and designed to navigate the bladder's interior wall tissue.
- Published
- 2024
46. DYNAMIC SYSTEMS AND CONTROL DIVISION: TECHNICAL DIRECTIONS OVER THE LAST 20 YEARS.
- Author
-
AUSLANDER, DAVID M.
- Subjects
PUBLICATIONS ,NANOTECHNOLOGY ,RESEARCH ,MECHANICAL engineering ,TIME delay systems ,UNIVERSITIES & colleges ,ENGINEERING - Abstract
The article focuses on the history of Dynamic Systems and Control Division of American Society Of Mechanical Engineers (ASME). Its periodical "Journal of Dynamic Systems, Measurement, and Control" (JDSMC) has been a research publication. The articles from journal suggested that it dominated the university-based work. Industrial participation has been the top priority in its topics with other areas being nanotechnology, multivehicle control, time-delay systems and automotives. All articles of the journal except the topic of time-delay systems refer to mechanical systems.
- Published
- 2013
- Full Text
- View/download PDF
47. Challenges for the Emerging Decade.
- Author
-
Ballal, Dilip
- Subjects
ENGINEERING ,MECHANICAL engineering ,NUCLEAR engineering ,NUCLEAR energy ,GAS turbines ,POWER resources ,GREEN technology - Abstract
The article provides information on the nuclear power engineering research by the Nuclear Engineering Division of the American Society of Mechanical Engineers published in the "Journal of Engineering for Gas Turbines and Power" (JEGTP) in the U.S. In April 2008, the Division selected JEGTP for the publication of the studies relating to gas turbines, energy and power. These papers provide the best technological solutions to define the technology, policy and market issues to achieve a more sustainable energy system.
- Published
- 2009
48. Committee Reports.
- Subjects
MANUFACTURING process automation ,MECHANICAL engineering ,MECHANICAL engineers ,AUTOMATION ,SOCIETIES ,CONFERENCES & conventions - Abstract
The article presents information on the Design Automation Committee (DAC) of the American Society of Mechanical Engineers (ASME). The DAC implements projects in the areas of design representation, optimization, integration and evaluation. The committee sponsored the 39th Design Automation Conference which was held in Portland Oregon, and will sponsored the 2014 ASME IDETC Design Automation Conference in Buffalo, New York.
- Published
- 2013
49. COMMITTEE REPORTS.
- Author
-
Lewis, Kemper, Esterman, Marcos, McAdams, Daniel A., Horauer, Martin, Berger, Edward, Mikkola, Aki, Singh, Avinash, Sandu, Corina, Shen, I. Y. (Steve), and Ferguson, Scott
- Subjects
MECHANICAL engineering ,CONFERENCES & conventions ,RESEARCH awards ,SCIENTISTS ,AWARDS - Abstract
The article offers various developments related to mechanical engineering. Singiresu S. Rao from the University of Miami is the recipient of the 2012 Design Automation Award. The 24th International Conference on Design Theory and Methodology was held in Chicago, Illinois. The MNS Innovator Award has been announced which recognizes impact and innovation across MNS research areas.
- Published
- 2012
50. Energy Committee Issues Two More Talking Points.
- Subjects
MECHANICAL engineering ,PETROLEUM products ,NUCLEAR fuels ,URANIUM ,INTERNATIONAL trade - Abstract
The article reports that the Energy Committee of American Society of Mechanical Engineers (ASME) has issued two papers in the Energy Talking Points series. It states that the paper, ETP3 examines oil imports for transportation sector in the U.S., and around 1 billion dollars a day is spent by U.S. to import petroleum. It mentions that ETP4 discusses nuclear fuel cycle, for reprocessing and switching to reactors capable of fissioning isotopes of uranium.
- Published
- 2011
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