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2010 Asia-Pacific International Symposium on Aerospace Technology, APISAT 2010

作者： Zhong, Lei Hiroki, Ura Masayoshi, Noguchi Department of Mechanical Systems Engineering Tokyo University of Science Suwa Nagano-ken Japan Aviation Program Group Japan Aerospace Exploration Agency Tokyo Japan

ISBN: (纸本)9787561228999

Noise reduction is an import problem to realize the next generation supersonic transport to achieve environmentally acceptable noise level at take-off and landing. The objective of this study is to reduce the flap tip noise by extending trailing-edge flap in spanwise. Noise measurement was conducted to investigate effects of flap tip devices on noise reduction for a supersonic civil transport configuration. Noise sources of airframe noise were identified by using a phased-array microphone measurement system, and it showed that the airframe noise mainly contributed from tips of the leading-edge and trailing-edge flaps. Results showed that noise levels were reduced by flap tip devices, and effects of noise reduction were confirmed.

关键词： Aerodynamics Flap Noise Supersonic transport

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Energy dissipation and intrinsic loss in single walled carbon nanotubes due to anelastic relaxation

Energy dissipation and intrinsic loss in single walled carbo...

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作者： Zhou, Zhong Qian, Dong Yu, Min-Feng Mechanical Engineering Program School of Dynamic Systems University of Cincinnati Cincinnati OH 45221 United States Department of Mechanical Science and Engineering University of Illinois at Urbana-Champaign Urbana IL 61801 United States

Based on the molecular dynamics simulation and an elastic shell model, we investigated the intrinsic loss under dynamic excitations in single walled carbon nanotube (SWCNT) due to the anelastic relaxation mechanism. We quantified the anelastic property of SWCNTs, i.e., the creep compliances, and showed them to be on the order of 1 (TPa-1) and sensitive to both the radius of SWCNT and the loading rate. Furthermore, our study showed that the time scale for a SWCNT to fully achieve its equilibrium elastic property through anelastic relaxation is on the order of nanosecond. This leads to significant intrinsic loss and damping for SWCNT resonators operating at the Gigahertz frequency range. Both the loss angle and quality (Q) factor of SWCNT were found to be strongly dependent on the load frequency. A dissipation peak and thus a low Q factor were observed in the Gigahertz frequency range. On the other hand, high Q factor and low dissipation were achieved in the range of low (

关键词： Energy dissipation

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Study of Integral Variable Structure Control Method for Stability of SI Engine Idling Speed

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Journal of Software Engineering and Applications 2010年第8期3卷 813-819页

作者： Yang Zhang Nobuo Kurihara Science Program in Mechanical Systems Hachinohe Institute of Technology Graduate School of Engineering Hachinohe Institute of Technology

The intake air control system of a gasoline engine is a typical nonlinear system, and included among the adverse fac-tors that always induce poor idle-speed control stability are dead time and disturbances in the intake air control process. In this paper, to improve the responsiveness when idling with regard to disturbances, a mean-value engine model (MVEM) with dead time was constructed as the control object, and the two servo structures of sliding mode control (SMC) were studied for better idle control performance, especially in transient process of speed change. The simulation results confirmed that under the constraint condition of control input, the robustness of idle speed control that is being subjected to torque disturbances and noise disturbances can be greatly improved by use of the servo structure II.

关键词： SI Engine Idle Speed Control Variable Structure Integral Sliding Mode Control Simulation

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A new approach to measure melamine, cyanuric acid, and melamine cyanurate using surface enhanced Raman spectroscopy coupled with gold nanosubstrates

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Sensing and Instrumentation for Food Quality and Safety 2008年第1期2卷 66-71页

作者： He, Lili Liu, Yang Lin, Mengshi Awika, Joseph Ledoux, David R. Li, Hao Mustapha, Azlin Food Science Program Division of Food Systems and Bioengineering University of Missouri Columbia MO 65211 United States Department of Animal Sciences University of Missouri Columbia MO 65211 United States Department of Mechanical and Aerospace Engineering University of Missouri Columbia MO 65211 United States

Vibrational spectroscopic characteristics of melamine, cyanuric acid, and melamine cyanurate were measured using surface-enhanced Raman spectroscopy (SERS) coupled with gold nanosubstrates. Trace amounts of melamine and its analogues (cyanuric acid and melamine cyanurate) were characterized and quantified quickly and accurately by SERS in combination with partial least squares (PLS) analysis. Based on the relationship between the Raman intensity of the most prominent peak at around 676 cm-1 and log values of melamine concentrations, the limit of detection (LOD) of SERS for melamine was estimated to be 2.6 × 10-7 mol L-1 (∼33 ppb). An approximately 3 × 104 fold of enhancement factor for SERS signals of melamine on gold nanosubstrates was obtained. This result was based upon the comparison of the peak at around 676 cm-1 in the SERS spectra with that of normal Raman spectra of melamine in aqueous solutions. SERS spectra of cyanuric acid acquired from its solid form differ significantly from this compound in an aqueous solution, indicating a possible keto-enol isomerization reaction of cyanuric acid in water. When equal amounts of melamine and cyanuric acid were added together, spoke-like crystals of melamine cyanurate formed instantly, which could be measured and characterized by SERS. This study demonstrates that SERS could provide a fast and ultra-sensitive tool for detection and characterization of melamine and its derivative compounds in aqueous solutions. © Springer science+Business Media, LLC 2008.

关键词： Melamine

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A Player Position Tracking Method Based on a Wide-Area Pan-Tilt-Zoom Video 12

A Player Position Tracking Method Based on a Wide-Area Pan-T...

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Proceedings of the 12th International Conference on Sport sciences Research and Technology Support, icSPORTS 2024

作者： Yamagishi, Shunzo Xie, Chun Shishido, Hidehiko Kitahara, Itaru Master's and Doctoral Program in Intelligent Mechanical Interaction Systems University of Tsukuba Ibaraki Japan Center for Computational Sciences University of Tsukuba Ibaraki Japan Faculty of Science and Engineering Department of Information Systems Engineering Soka University Tokyo Japan

ISBN: (纸本)9789897587191

This paper proposes a method to estimate the posture of an athlete moving on a vast field in a sporting event using a pan-tilt-zoom camera. In order to estimate the posture of an athlete on a sports field from a dynamic video sequence, our method extracts image features to search correspondence points among successive frames and computes the homography transformation matrix that compensates for changes the camera parameters (e.g., angle of view and posture). The effectiveness of this method is qualitatively verified using MLB TV broadcast video. The accuracy and error factors are also quantitatively verified by CG simulation. Copyright © 2024 by SCITEPRESS - science and Technology Publications, Lda.

关键词： Pan-Tilt-Zoom Camera Player Tracking Sports Analytics Video Processing Wide-Area

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Cyclic strain resistance, deformation and fracture behavior of a novel alloy steel 3

Cyclic strain resistance, deformation and fracture behavior ...

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3rd Biennial Symposium on Fatigue of Materials: Advances and Emergences in Understanding, held during Materials science and Technology 2014, MS and T 2014

作者： Manigandan, K. Srivatsan, T.S. Vasudevan, V.K. Tammana, D. Poorbangi, B. Division of Materials Science and Engineering Department of Mechanical Engineering University of Akron AkronOH44325-3903 United States School of Dynamic Systems Materials Science and Engineering Program University of Cincinnati CincinnatiOH45221-0072 United States

ISBN: (纸本)9781119041481

In this paper, the results of a study on microstructural influences on cyclic strain response, deformation and fracture behavior of an alloy steel is presented Cyclic strain resistance exhibited a linear trend for the variation of both elastic strain amplitude with reversals-to-failure, and plastic strain amplitude with reversals-to-failure. Fracture morphology was observed to be the same at the macroscopic level over the entire range of cyclic strain amplitudes examined. However, at the fine microscopic level this alloy steel revealed fracture to be mixed-mode with features reminiscent of "locally" ductile and brittle failure mechanisms. The mechanisms governing strain response at the fine microscopic level, resultant fatigue life, and final fracture behavior are presented and discussed in light of the mutually interactive influences of intrinsic microstructural effects, deformation characteristics of the microstructural constituents during fully-reversed strain cycling, magnitude of cyclic strain amplitude, and resultant fatigue life.

关键词： Alloy steel

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Erosion-corrosion resistance of Mo-Ti- and Ni-Cr-Mo-alloyed medium-carbon martensitic steels: a critical analysis of synergistic effect of erosion and corrosion

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Journal of Iron and Steel Research International 2022年第8期29卷 1299-1311页

作者： De-fa Li Hang-yu Dong Cheng-yang Hu Kai-ming Wu Serhii Yershov Oleg Isayev School of Mechanical and Vehicle Engineering West Anhui UniversityLuan 237012AnhuiChina The State Key Laboratory of Refractories and Metallurgy Hubei Province Key Laboratory of Systems Science on Metallurgical ProcessingInternational Research Institute for Steel TechnologyWuhan University of Science and TechnologyWuhan 430081HubeiChina Laboratory for Excellence in Advanced Steel Research Materials Science and Engineering ProgramDepartment of MetallurgicalMaterials and Biomedical EngineeringUniversity of Texas at El PasoEl PasoTX 79968USA

Grain refinement renders Mo-Ti-alloyed medium-carbon martensitic steel to exhibit high hardness,high strength,and good toughness,but the erosion-corrosion resistance of steel in a corrosive slurry environment is not ***-Ti-alloyed medium-carbon martensitic steel is compared with Ni-Cr-Mo-alloyed medium-carbon martensitic steel,and the erosion-corrosion resistance of those two steels under impingement by NaCl solution with gravels has been *** components,pure-corrosion rate,pure-erosion rate,and synergistic effect of erosion and corrosion(SEEC)of erosion-corrosion rate,were *** pure-corrosion and pure-erosion rates of Mo-Ti-alloyed steel were higher than those of Ni-Cr-Mo-alloyed one;however,its erosion-corrosion rate was relatively lower because of a weak *** plastic deformation and work hardening due to gravel impingement were the essential reason for SEEC,which could be reduced by grain refinement,and consequently,Mo-Ti-alloyed steel with finer grains had better erosion-corrosion *** refinement could be an effective way to improve the erosion-corrosion resistance of martensitic steels.

关键词： Grain refinement Mo-Ti alloying Ni-Cr-Mo alloying Martensite Erosion-corrosion

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Cyclic strain resistance, stress response, fatigue life, and fracture behavior of high strength low alloy steel 300 M

Cyclic strain resistance, stress response, fatigue life, and...

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作者： Manigandan, K. Srivatsan, T.S. Tammana, Deepthi Poorgangi, Behrang Vasudevan, Vijay K. Department of Mechanical Engineering University of Akron Akron OH 44325-3903 United States School of Dynamic Systems Materials Science and Engineering Program University of Cincinnati Cincinnati OH 45221-0072 United States

The focus of this technical manuscript is a record of the specific role of microstructure and test specimen orientation on cyclic stress response, cyclic strain resistance, and cyclic stress versus strain response, deformation and fracture behavior of alloy steel 300 M. The cyclic strain amplitude-controlled fatigue properties of this ultra-high strength alloy steel revealed a linear trend for the variation of log elastic strain amplitude with log reversals-to-failure, and log plastic strain amplitude with log reversals-to-failure for both longitudinal and transverse orientations. Test specimens of the longitudinal orientation showed only a marginal improvement over the transverse orientation at equivalent values of plastic strain amplitude. Cyclic stress response revealed a combination of initial hardening for the first few cycles followed by gradual softening for a large portion of fatigue life before culminating in rapid softening prior to catastrophic failure by fracture. Fracture characteristics of test specimens of this alloy steel were different at both the macroscopic and fine microscopic levels over the entire range of cyclic strain amplitudes examined. Both macroscopic and fine microscopic observations revealed fracture to be a combination of both brittle and ductile mechanisms. The underlying mechanisms governing stress response, deformation characteristics, fatigue life, and final fracture behavior are presented and discussed in light of the competing and mutually interactive influences of test specimen orientation, intrinsic microstructural effects, deformation characteristics of the microstructural constituents, cyclic strain amplitude, and response stress. © 2014 ASM International.

关键词： Microstructure

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0906 | Experimental Investigation of Increased Bearing Capacity When Imparting Vibration to Loose Ground in Low Atmospheric Pressure 21

0906 | Experimental Investigation of Increased Bearing Capac...

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21st International and 12th Asia-Pacific Regional Conference of the International Society for Terrain-Vehicle systems, ISTVS 2024

作者： Watanabe, Tomohiro Iizuka, Kojiro Department of Engineering Mechanical Engineering Program Niigata University Niigata Prefecture Niigata City Japan Department of Science and Engineering Machinery and Control Systems Shibaura Institute of Technology Saitama Prefecture Saitama City Japan

ISBN: (纸本)9781942112570

Recently, legged robots have attracted considerable attention as highly mobile rovers for planetary exploration. However, the surfaces of celestial bodies such as Mars and the Moon are primarily loose, causing slippage due to surface deformation from the rover's leg movements. To mitigate this, a walking method aimed at preventing slippage was proposed. In this walking method, the bearing capacity is increased by imparting vibration from the rover's leg to the loose soil on the ground. This walking method improved the mobility performance of the legged rover. It is crucial to investigate the increase in bearing capacity by imparting vibration in a realistic space environment to validate the effectiveness of the proposed method. This study examines the change in bearing capacity due to vibration under low atmospheric pressure, a condition found on Mars and the Moon. This condition affects the characteristics of ground sand due to decreased air resistance. Our findings provide valuable insights into using vibration in planetary exploration to enhance the performance of legged rovers. The experimental results indicate that the bearing capacity under low atmospheric pressure is nearly identical to that under standard atmospheric pressure, suggesting that atmospheric pressure conditions have minimal impact on the bearing capacity when vibration is applied. © 2024 International Society for Terrain-Vehicle systems. All rights reserved.

关键词： Atmospheric pressure

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National science foundation Earthquake Engineering Research Centers

National science foundation Earthquake Engineering Research ...

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2001 Structures Congress and Exposition, Structures 2001

作者： Pauschke, Joy Preston, Lynn Division of Civil and Mechanical Systems National Science Foundation 4201 Wilson Boulevard Arlington VA 22230 United States ERC Program Team Division of Engineering Education and Centers National Science Foundation 4201 Wilson Boulevard Arlington VA 22230 United States

ISBN: (纸本)0784405581

In 1997, the National science Foundation (NSF) funded three Earthquake Engineering Research Centers (EERCs) to focus on earthquake hazard mitigation through systems-oriented research, education and outreach, and industrial/practitioner/end user collaboration and technology transfer. Collectively receiving about one third of the total annual funding in NSF's earthquake engineering research portfolio, the three EERCs enable cross-disciplinary, cross-institutional teams of faculty and students to work collaboratively, in partnership with industry, practitioners and other end users, over a long-term period, on science, engineering, and societal research issues related to earthquake hazard mitigation. This paper presents an overview of the key features of the EERCs and their individual and collaborative efforts. © 2004 ASCE.

关键词： Earthquake engineering

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