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AIAA Science and Technology Forum and Exposition, AIAA SciTech Forum 2025

作者： Lu, Wei-Chun Oudghiri-Idrissi, Othman Poli, Andrea Arruda, Ellen M. Tol, Serife Department of Mechanical Engineering University of Michigan 2350 Hayward St Ann ArborMI48109 United States Fariborz Maseeh Department of Civil Architectural and Environmental Engineering The University of Texas at Austin 301 E. Dean Keeton St AustinTX78712 United States Department of Mechanical Engineering Macromolecular Science and Engineering Program University of Michigan 2350 Hayward St Ann ArborMI48109 United States

ISBN: (数字)9781624107238

ISBN: (纸本)9781624107238

The precision of space structures is sensitive to high-temperature variation during on-orbit operations. This work develops zero thermal expansion (ZTE) metamaterials that can be integrated into space structures to restrict large thermal deformation under precision requirements. The proposed bi-material ZTE metamaterial beams show extremely low coefficients of thermal expansion (CTE) for a wide temperature variation. Static and dynamic analyses are conducted on the designed metamaterials for performance evaluation. The proposed ZTE beam elements are integrated into a 48-meter rib of a space RF antenna to enhance its thermal precision over a wide temperature range. Further, experimental validation of the ZTE truss beam design is conducted in a thermal chamber to demonstrate its low thermal deformation compared to a reference aluminum truss beam. © 2025, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

关键词： Trusses

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Comparison of Advanced Sample Preparation Techniques for High-Resolution Imaging of Sponge Spicule Cross-Sections

Comparison of Advanced Sample Preparation Techniques for Hig...

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Symposium on Natural Fibers and Biocomposites: A Sustainable Solution, 2025, held as part of the TMS Annual Meeting and Exhibition, TMS 2025

作者： Tavangarian, Fariborz Fani, Niloofar Monfared, Armaghan Hashemi Sadeghzade, Sorour Mechanical Engineering Program School of Science Engineering and Technology Pennsylvania State University Harrisburg MiddletownPA17057 United States Department of Biomedical Engineering Pennsylvania State University State College University ParkPA16802 United States School of Engineering Westlake University Hangzhou310024 China

ISBN: (纸本)9783031811890

This study comprehensively investigates the effectiveness of three advanced sample preparation techniques—ion milling, laser cuttingLaser-based techniques, and Focused Ion Beam (FIB) milling—for high-resolution imaging of Euplectella aspergillum sponge fibers called spicules. Primarily composed of silica layers with nanometer-scale organic interlayers, spicules possess complex hierarchical structures which are critical for their mechanical propertiesmechanical property. Accurate characterizationCharacterization of these structures requires advanced sample preparation to prevent artefacts and preserve structural integrity. Ion milling introduced significant surface degradation and uneven material removal in spicules. Despite its precision, laser cutting caused thermal damage and induced micro-cracks, compromising the microstructural integrity. In contrast, FIB milling provided superior results, producing smooth, artefact-free cross-sections with minimal thermal and mechanical stress. The real-time imaging capability of FIB milling further ensured optimal sample preparation, making it the most suitable technique for delicate biological materials like spicules. The findings of this study provide valuable insights into the preparation of biological samples for further research and analysis. © The Minerals, Metals & Materials Society 2025.

关键词： Milling (machining)

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Takeoff Parameter Estimation for a Subscale Flight Test of an Amphibious Floatplane

Takeoff Parameter Estimation for a Subscale Flight Test of a...

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AIAA Science and Technology Forum and Exposition, AIAA SciTech Forum 2025

作者： Rocha, Ana C. S. Medeiros, Eduardo Bauzer Magalhães, Tarcisio Faustino Tofaneli, Luzia Aparecida Oliveira, Turan Dias Sieves, Guilherme Benaci Guimarães, Tamara Graduate Program of Mechanical Engineering Federal University of Minas Gerais MG Belo Horizonte31270-901 Brazil Department of Energy Senai CIMATEC University Center BA Salvador41650-010 Brazil Department of Mechanical Engineering The Pennsylvania State University University ParkPA16802 United States

ISBN: (数字)9781624107238

ISBN: (纸本)9781624107238

The recent renewed interest in amphibious seaplane operation has stimulated the research related to this class of airplane. In fact, modern techniques previously developed for conventional land planes are now being modified to suit the development of these aircraft. Even though computer simulation presently offers highly efficient design tools there is still the need for experimental testing. Modern development of micro electric motors and actuators, together with the development of compact power electronics have laid the conditions for the development of Subscale Flight Testing (SFT), a very efficient tool for the improvement of the aircraft modeling process. The present research addresses the problem of conceptual design of reduced scale f loatplanes. Takeoff performance, one of the most complex flight phases of an amphibious airplane, is considered a modeling process considerably more difficult than the corresponding conventional land estimation. A typical floatplane, now being designed by the authors, is used to illustrate this development. The dynamic scaling process is described, and the expected performance of a reduced scale is shown. The authors expect to use in the near future the acquired insight to carry their own SFT flight test, and also improve modeling also providing improvements applicable to computer simulation. © 2025, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

关键词： Amphibious aircraft

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The Centrifugal Nuclear Thermal Rocket: Foundations, Challenges, and Progress

The Centrifugal Nuclear Thermal Rocket: Foundations, Challen...

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AIAA Science and Technology Forum and Exposition, AIAA SciTech Forum 2025

作者： Thomas, Dale Houts, Michael Wang, Dean Hollingsworth, Keith Frederick, Robert Cassibry, Jason Department of Industrial & Systems Engineering and Engineering Management The University of Alabama in Huntsville HuntsvilleAL35899 United States Space Nuclear Propulsion Program Office NASA Marshall Space Flight Center HuntsvilleAL35812 United States Department of Mechanical & Aerospace Engineering The Ohio State University ColumbusOH43210 United States Department of Mechanical & Aerospace Engineering and Interim Dean of the Honors College The University of Alabama in Huntsville HuntsvilleAL35899 United States Department of Mechanical & Aerospace Engineering Propulsion Research Center The University of Alabama in Huntsville HuntsvilleAL35899 United States Department of Mechanical & Aerospace Engineering The University of Alabama in Huntsville HuntsvilleAL35899 United States

ISBN: (数字)9781624107238

ISBN: (纸本)9781624107238

The Centrifugal Nuclear Thermal Rocket (CNTR) is a Nuclear Thermal Propulsion (NTP) concept designed to heat propellant directly by the reactor fuel. The primary difference between the CNTR concept and traditional NTP systems is that rather than using traditional solid fuel elements, the CNTR uses liquid fuel with the liquid contained in rotating cylinders by centrifugal force. If the concept can be successfully realized, the CNTR would have a high specific impulse (up to 1800 s) at high thrust, which may enable (i) viable near-term human Mars exploration by reducing round-trip times to 420 days and (ii) direct injection orbits for scientific rendezvous missions to the Solar System outer planets and Kuiper Belt objects. Research is presently underway to determine resolutions for the significant engineering challenges that the CNTR concept presents. These challenges, the study plans to address them, and progress have been described previously;this paper provides an update on progress to date for the overall research effort, including strategies and key results on revision of a reference configuration, definition of key parameters which allows integration of the results of various analyses, and reviews strategies to mitigate the problem of Uranium vapor saturating the propellant exhaust and significantly impacting the CNTR’s specific impulse. Analyses and experiments, both underway and planned, to update estimates of engine key performance parameters including specific impulse, thrust and thrust to weight ratio along with the identification of selected design margins within the engine itself are described – all toward the goal of enabling plans for a laboratory demonstration of a single Centrifugal Fuel Element. © 2025, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

关键词： Rockets

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Bimetallic Nanoporous Carbon-Based Direct-Current Triboelectric Nanogenerators for Biomechanical Energy Harvesting and Sensing

SSRN

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SSRN 2025年

作者： Rahman, Muhammad Toyabur Rahman, Md Sazzadur Kim, Young-Seong Lim, Joong Yeon Kim, Seonghwan Department of Mechanical and Manufacturing Engineering University of Calgary CalgaryAB Canada Department of Mechanical Robotics and Energy Engineering Dongguk University Seoul Korea Republic of

A high-power density direct current triboelectric nanogenerator (DC-TENG) presents a promising solution for sustainable and distributed energy supply in the Industry 4.0 era, catering to electronics and sensor networks. This study introduces a contact-separation mode DC-TENG that incorporates core-shell metal-organic framework-derived bimetallic nanoporous carbon (BNPC) as a functional nanofiller in the negative elastomer tribo-layer, significantly enhancing its performance. The synergistic effects of micro-capacitor formation, interfacial polarization, and graphitization-driven conductive networks make BNPC an ideal filler, as its high surface area and porosity improve dielectric properties and charge trapping, while its bimetallic components suppress charge recombination. Additionally, a Kapton-based mechanical rectifier is integrated to enable direct DC output, simplifying the system design and enhancing energy utilization. The optimized BNPC@elastomer composite-based DC-TENG (BNDC-TENG) exhibits a peak power density of 6.32 W/m2, demonstrating remarkable durability over 43,000 cycles and the ability to directly charge capacitors and power small electronics. Furthermore, the BNDC-TENG efficiently harvests biomechanical energy from human motion and functions as a self-powered sensor for real-time activity monitoring (e.g., walking and running). This work introduces innovative materials and a simplified architecture for high-performance DC-TENGs, advancing sustainable energy harvesting and next-generation self-powered sensing applications. © 2025, The Authors. All rights reserved.

关键词： Charge trapping

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ANN-based analysis of thin film Maxwell fluid dynamics with electro-osmotic and nonlinear thermal effects

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Alexandria engineering Journal 2025年 127卷 392-410页

作者： Din, Irfan Saif Ud Siddique, Imran Zahid, Zohaib Nadeem, Muhammad Islam, S. Department of Mathematics University of Management and Technology Lahore54770 Pakistan Department of Mathematics University of Sargodha Sargodha40100 Pakistan Mathematics in Applied Sciences and Engineering Research Group Scientific Research Center Al-Ayen University Nasiriyah64001 Iraq Federal University of Technology Paran UTFPR Mechanical Engineering Department DAMEC Postgraduate Program in Mechanical and Materials Engineering PPGEM Research Center for Rheology and Non-Newtonian Fluids CERNN R. Deputado Heitor Alencar Furtado 5000 - Bloco N - Ecoville PR Curitiba81280-340 Brazil Department of Mechanical Engineering Prince Mohammad Bin Fahd University P.O Box 1664 Al Khobar31952 Saudi Arabia

An intelligent Levenberg-Marquardt Technique (LMT) with artificial neural network (ANN) backpropagation (BP) has been used to analyze the thermal heat and mass transfer of unsteady magnetohydrodynamics (MHD) thin film Maxwell fluid flow in a porous inclined sheet with an emphasis on the influence of electro-osmosis. The activation energy, chemical reaction, mixed convection, melting heat, joule heating, nonlinear thermal radiation, variable thermal conductivity and thermal source/sink effect are taken into account for transport expressions. Appropriate similarity transformations were used to translate partial differential equations (PDEs) into ordinary differential equations (ODEs). After that, the built-in MATLAB BVP4C method was used for a data set assessed using the LMT-ANN strategy to solve these ODEs. The physical significance of the designed parameters is thoroughly discussed in both tabular and graphical form. The observed R-squared value is 1, and the mean square error up to 10−15 demonstrates the LMT-ANN's precise and accurate computing capability. The model's validity is also confirmed by the strong agreement between the obtained predicted findings and numerical results, which shows a high degree of accuracy within the range of 10−8 to 10−11. It was revealed that radiative heat considerably increases surface heat energy through accumulation, improving heat transfer qualities, whereas fluid temperature is raised by Joule dissipation, variable thermal conductivity, and heat source. Electro-osmosis and magnetic fields reduce fluid velocity by generating opposing forces that resist the flow. This problem works best in microscale fluid transport systems and drilling operations, where magnetic and electro-osmotic control are crucial. These systems include micro-electromechanical systems, lab-on-a-chip devices, porous geological formations, and thin film coating technologies. © 2025 The Authors

关键词： Activation energy

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Knowledge-guided temperature correction method for soluble solids content detection of watermelon based on Vis/NIR spectroscopy

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Artificial Intelligence in Agriculture 2025年第1期15卷 88-97页

作者： Zhizhong Sun Jie Yang Yang Yao Dong Hu Yibin Ying Junxian Guo Lijuan Xie College of Biosystems Engineering and Food Science Zhejiang UniversityHangzhou 310058PR China College of Chemistry and Materials Engineering Zhejiang A&F UniversityHangzhou 311300PR China Key Laboratory of Intelligent Equipment and Robotics for Agriculture of Zhejiang Province Hangzhou 310058PR China The National Key Laboratory of Agricultural Equipment Technology Beijing 100083PR China Department of Bioproducts and Biosystems Engineering University of MinnesotaSaint PaulMN 55108USA Zhejiang University School of Medicine Division of Scientific Research(ZJU-QILU joint research institute)Hangzhou 310058PR China College of Optical Mechanical and Electrical EngineeringZhejiang A&F UniversityHangzhou 311300PR China College of Mechanical and Electrical Engineering Xinjiang Agricultural UniversityUrumqi 830052PR China

Visible/near-infrared(Vis/NIR)spectroscopy technology has been extensively utilized for the determination of soluble solids content(SSC)in ***,the spectral distortion resulting from temperature variations in the sample leads to a decrease in detection *** mitigate the influence of temperature fluctuations on the accuracy of SSC detection in fruits,using watermelon as an example,this study presents a knowledge-guided temperature correction method utilizing one-dimensional convolutional neural networks(1D-CNN).This method consists of two stages:the first stage involves utilizing 1D-CNN models and gradient-weighted class activation mapping(Grad-CAM)method to acquire gradient-weighted features correlating with *** second stage involves mapping these features and integrating them with the original Vis/NIR spectrum,and then train and test the partial least squares(PLS)*** knowledge-guided method can identify wavelength bands with high temperature correlation in the Vis/NIR spectra,offering valuable guidance for spectral data *** performance of the PLS model constructed using the 15℃ spectrum guided by this method is superior to that of the global model,and can reduce the root mean square error of the prediction set(RMSEP)to 0.324°Brix,which is 32.5%lower than the RMSEP of the global model(0.480°Brix).The method proposed in this study has superior temperature correction effects than slope and bias correction,piecewise direct standardization,and external parameter orthogonalization correction *** results indicate that the knowledge-guided temperature correction method based on deep learning can significantly enhance the detection accuracy of SSC in watermelon,providing valuable reference for the development of PLS calibration methods.

关键词： Visible/near-infrared spectroscopy Temperature correction Watermelon Knowledge-guided Convolutional neural network

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Intra-Operative 3-D Modeling of Side Branch Vessels for IVUS-Guided Catheter Navigation

IEEE Transactions on Medical Robotics and Bionics

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IEEE Transactions on Medical robotics and Bionics 2025年第2期7卷 443-454页

作者： Farola Barata, Beatriz Beckers, Wim-Alexander Borghesan, Gianni Dall'Alba, Diego Bennett, Johan McCutcheon, Keir Fiorini, Paolo Vander Sloten, Jos Vander Poorten, Emmanuel KU Leuven Robot-Assisted Surgery Group Department of Mechanical Engineering Leuven3001 Belgium University of Verona Altair Robotics Laboratory Department of Computer Science Verona Verona37129 Italy Flanders Make KU Leuven Leuven3001 Belgium KU Leuven Department of Cardiovascular Sciences Leuven3000 Belgium UZ Leuven Department of Cardiovascular Diseases Leuven3000 Belgium

Despite continuous advances in three-dimensional (3D) fusion imaging, two-dimensional (2D) X-ray-based fluoroscopy is still the gold standard intra-operative image guidance tool in endovascular interventions. The adoption of robotic technology offers the potential to bring intra-operative radiation exposure down to a minimum, or even eliminate it. Non ionizing approaches, such as Intravascular Ultrasound (IVUS), are progressively explored as standalone or fluoroscopy-adjunct techniques for 3D vasculature reconstruction. We have previously demonstrated the feasibility of real-time 3D Main Vessel (MV) modeling from the fusion of IVUS and EM pose data obtained from sensors embedded at the tip of a robotic catheter. This paper proposes to advance MV modeling towards a comprehensive radiation-free 3D guidance framework by means of intra operative Side Branch (SB) detection and modeling. Two models are proposed to approximate the geometry of SB vessel ostia: a sphere and a cylinder. An Unscented Kalman Filter (UKF) recursively estimates the state of these models considering the MV model, while the catheters navigates through the vessel. In silico and in vitro validation results show the potential clinical value of the proposed strategy for facilitating safer robotic catheter steering. © 2018 IEEE.

关键词： Medical robotics

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Raise Damping in Electro-Hydraulic Systems with Observed Pressure

Raise Damping in Electro-Hydraulic Systems with Observed Pre...

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Mechatronics and robotics engineering (ICMRE), International Conference on

作者： Xieli Zhang Damiano Padovani Department of Mechanical Engineering (Robotics) Guangdong Technion-Israel Institute of Technology Shantou China

ISBN: (数字)9798331509293

ISBN: (纸本)9798331509309

The growing interest in energy efficiency points the research for hydraulic systems to electro-hydraulic drives, specifically hydraulic actuators directly coupled to pumps driven by electric motors. This design eliminates functional energy dissipations and enables energy recovery but leads to inherently low damping. The consequence is that harmful payload oscillations deteriorate the position control's accuracy of the actuator. Therefore, raising the drive damping via pressure feedback is crucial and requires knowledge of the pressure in both actuator chambers. This paper investigates using pressure observation to that end (i.e., a virtual pressure sensor implemented via software replaces two physical pressure transducers). High-passed pressure feedback is introduced using a model-based design for setting up closed-loop position control. This approach is simulated numerically on a heavy-duty robotic manipulator. The results confirm that the payload oscillations are significantly reduced without affecting position tracking.

关键词： Damping Transducers Soft sensors Position control Observers Robot sensing systems Manipulators Sensor systems Oscillators Payloads

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Towards Local Minima-free Robotic Navigation: Model Predictive Path Integral Control via Repulsive Potential Augmentation

Towards Local Minima-free Robotic Navigation: Model Predicti...

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IEEE/SICE International Symposium on System Integration

作者： Takahiro Fuke Masafumi Endo Kohei Honda Genya Ishigami Department of Mechanical Engineering Space Robotics Group Keio University Yokohama Japan Department of Mechanical Systems Engineering Mobility System Group Nagoya University Nagoya Japan

ISBN: (数字)9798331531614

ISBN: (纸本)9798331531621

Model-based control is a crucial component of robotic navigation. However, it often struggles with entrapment in local minima due to its inherent nature as a finite, myopic optimization procedure. Previous studies have addressed this issue but sacrificed either solution quality due to their reactive nature or computational efficiency in generating explicit paths for proactive guidance. To this end, we propose a motion planning method that proactively avoids local minima without any guidance from global paths. The key idea is repulsive potential augmentation, integrating high-level directional information into the Model Predictive Path Integral control as a single repulsive term through an artificial potential field. We evaluate our method through theoretical analysis and simulations in environments with obstacles that induce local minima. Results show that our method guarantees the avoidance of local minima and outperforms existing methods in terms of global optimality without decreasing computational efficiency.

关键词： Analytical models Costs Three-dimensional displays Navigation Computational modeling System integration Predictive models Planning Computational efficiency Robots

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