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作者： Ahn, Seok Hwan Seok, Kum Cheol Nam, Ki Woo School of Mechanical Engineering Pukyong National University San 100 Yongdang-dong Namgu 608-739 Busan Korea Republic of Department of UR Interdisciplinary Program Mechanical Engineering Graduate School Pukyong National University San 100 Yongdang-dong Nam-gu 608-739 Busan Korea Republic of Division of Materials Science and Engineering Pukyong National University San 100 Yongdang-dong Nam-gu 608-739 Busan Korea Republic of

The locally wall thinned phenomenon of pipes is simulated as metal loss due to erosion/corrosion. Therefore, fracture behaviors of pipes with local wall thinning are very important for the integrity of nuclear power plant. In this study, monotonic bending tests without internal pressure are conducted on 1.91-inch diameter Schedule 80 STS370 full-scale carbon steel pipe specimens. We investigated fracture strengths and failure modes of locally wall thinned pipes that welded and unwelded by four point bending test. From test results, we could be divided three types of failure modes.

关键词： Steel pipe

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Study of Machine Learning Techniques for Damage Identification in a Beam 10th

Study of Machine Learning Techniques for Damage Identifica...

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10th International Conference on Wave Mechanics and Vibrations, WMVC 2022

作者： da Silva Coelho, Jefferson de Sousa, Amanda Aryda Silva Rodrigues Machado, Marcela Rodrigues Dutkiewicz, Maciej Department of Mechanical Engineering University of Brasília Campus Universitário Darcy Ribeiro Faculdade de Tecnologia - Asa Norte DF Brasília Brazil Post-Graduate Program - Integrity of Engineering Materials University of Brasília Campus Universitário Darcy Ribeiro Faculdade de Tecnologia - Asa Norte DF Brasília70910-900 Brazil Faculty of Civil Environmental Engineering and Architecture University of Science and Technology Bydgoszcz85-796 Poland

ISBN: (纸本)9783031157578

Damage is defined as any change to the material, geometry or boundary condition that can modify the structure’s properties or response. In the past, damage identification was performed through periodical inspection, non-destructive testing/non-destructive evaluation, or visual observation. Structural health monitoring (SHM) has emerged to transition from offline damage identification to near real-time and online damage assessment. Hence, SHM is a damage detection strategy to monitor a structure for a period using a series of continuous measurement devices, which then collect the system’s characteristics and subsequently perform statistical analysis to assess the current circumstances and health of the structure. One of the first steps for the study of SHM is damage detection followed by monitoring. Machine Learning (ML) techniques can be used to develop viable algorithms to make potential predictions. ML algorithms are therefore providing the tools needed to enhance the capabilities of SHM systems and provide intelligent solutions to past challenges. Preliminary studies have reviewed that the extension of ML into SHM has dramatically increased the system’s capabilities, providing innovative solutions to different research challenges. This work conducts a study of the use of ML to identify damage in a beam and discuss the challenge of usage, performance and implementation of each technique. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Decision trees

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A flexible ultrasonic velocity profiler development environment

A flexible ultrasonic velocity profiler development environm...

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IEEE Instrumentation and Measurement Technology Conference

作者： César Yutaka Ofuchi Fabio Rizental Coutinho Raquel dos Santos Rasia Lucia Valeria Ramos de Arruda Flávio Neves Rigoberto Eleazar Melgarejo Morales Graduate School of Electrical Engineering and Computer Science (CPGEI) Federal University of Technology-Paraná (UTFPR) Curitiba Brazil Mechanical & Materials Engineering Postgraduate Program (PPGEM) Federal University of Technology-Paraná (UTFPR) Curitiba Brazil

ISBN: (纸本)9781467363846

Ultrasonic velocity profiler method is now an accepted tool in modern experimental fluid mechanics and fluid engineering. As a relative new technology, different applications and improvements of the technique are being researched over the last years. This paper presents an environment to develop new algorithms to improve the ultrasonic velocity estimation technique. The system uses the LabVIEW modular platform integrated with mathematical script language used in many signal-processing software. The phase-shift algorithm was implemented and tested using the proposed system. The results are validated with standard velocity measurements generated by a rotating cylinder.

关键词： Acoustics Velocity measurement Software Signal processing algorithms Ultrasonic variables measurement Fluids Doppler effect

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Understanding the Effect of Ni Content on Microstructures and Tensile Properties of Alsi10mg Alloy Samples Under a Variety of Solidification Rates

SSRN

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SSRN 2022年

作者： de Moura, Danusa Araújo de Gouveia, Guilherme Lisboa Gomes, Leonardo Fernandes Spinelli, José Eduardo Federal University of São Carlos Graduate Program in Materials Science and Engineering SP São Carlos13565-905 Brazil Department of Materials Engineering Federal University of São Carlos UFSCar SP São Carlos13565-905 Brazil

It is critical to gain a better knowledge of the impact of varying Ni contents on the microstructural changes of the AlSi10Mg alloy solidified at various cooling severities. Understanding the combined features of Si and Al3Ni phases constituting this modified alloy may also have a significant impact on understading its properties. In order to advance in these topics, AlSi10Mg alloys modified with, 1.0, 2.0 and 3.0 wt.% Ni are either directionally solidified (DS) at lower cooling rates or laser surface remelted (LSR) at higher rates. α-Al dendritic branches are found in the microstructure of all tested alloys either for DS or LSR specimens, surrounded by the eutectic constituent. Moreover, the dendritic array is defined by the secondary dendritic spacing, λ2, which is found to be 65% lower for the Ni-containing alloys than in the AlSi10Mg alloy. The microstructure of the quaternary alloys is constituted by the α-Al+Si+Al3Ni phases, with the Al3Ni phase having a prevalent fishbone shape and being found in higher proportions as a result of slow cooling and increasing Ni content. Ultimate tensile strength of the AlSi10Mg alloy is 190 MPa for a specified range of λ2 (22-30 μm), which is higher than that of Ni-containing alloys for the same range. However, Ni-containing alloys are more sensitive to λ2, and the DS AlSi10Mg-1Ni alloy, as well as a combination of samples solidified at no less than 3oC/s, fine dendritic spacing ( © 2022, The Authors. All rights reserved.

关键词： Thermoanalysis

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Investigation on Spark Plasma Sintering of Calcareous Waste Concrete Powder and Coal Fly Ash

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Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy 2023年第11期70卷 451-460页

作者： Kanda, Yasuyuki Shinjo, Tomohide Mechanical Engineering Program School of Engineering Faculty of Engineering University of the Ryukyus 1 Senbaru Nishihara-cho Okinawa Nakagami-gun903-0213 Japan Solid Mechanics and Materials Engineering Graduate School of Engineering and Science University of the Ryukyus 1 Senbaru Nishihara-cho Okinawa Nakagami-gun903-0213 Japan

This paper aims to fabricate a composite material using calcareous waste concrete powder and coal fly ash (FA) by spark plasma sintering. The effect of FA addition on the mechanical properties of the composite material were investigated. The maximum FA content was 7.5 wt%. The relative density of the composite material was approximately 1.0, independent of FA content. In contrast, the Vickers hardness, flexural strength, and flexural modulus increased with increasing FA content. However, the dispersion state of FA in the composite material was not observed by scanning electron microscopy. Powder X-ray diffraction of the composite material revealed that spurrite and wollastonite were formed identically, independent of FA content. Therefore, FA serves as a reinforcement in the composite material. © 2023 Japan Society of Powder and Powder Metallurgy.

关键词： Spark plasma sintering

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Accelerating Degradable Composite Breakdown Using Citrus Processing Side Streams

ACS Sustainable Resource Management

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ACS Sustainable Resource Management 2024年第2期1卷 344-354页

作者： Aline V. Duarte Laís T. Possari Lívia M. G. Gonçalves Baltus C. Bonse Talita R. Rigolin Sílvia H. P. Bettini Graduate Program in Materials Science and Engineering Federal University of Sao Carlos Rod. Washington Luiz 235 São Carlos 13565-905 Brazil Department of Materials Engineering Centro Universitário FEI 09850-901 São Bernardo do Campo Brazil Department of Materials Engineering Federal University of Sao Carlos Rod. Washington Luiz 235 São Carlos 13565-905 Brazil

Daily, vast amounts of waste are produced in the orange juice industry, a large part of which is reused in low-added-value products. In this work, orange vesicle fiber residues from the juice sieving stage were plasticized by extrusion, producing a thermoplastic citrus pulp (TCP). This pulp was incorporated into poly(butylene succinate) (PBS) at up to 50 wt %. The influence of TCP on the molar mass, morphology, tensile properties, rheological behavior, and biodeterioration of PBS in soil was evaluated. Highly flexible compounds with elongations similar to those of PBS were produced. Scanning electron microscopy analyses suggested good dispersion between the TCP and PBS phases, verified after acid extraction of pectin. Rheological analyses indicated the presence of strong interactions in the interconnected network formed by pectin gel, percolation of TCP lignocellulosic fibers, or both. Analyses of mass loss by burial in soil showed that the higher the TCP content in PBS is, the higher and faster the biodeterioration is. Size exclusion chromatography analyses indicated that the greater the concentration of TCP and the better dispersed it was in the compounds, the lower molar masses populations appeared in PBS, indicating higher rates of degradation of PBS in the presence of TCP. This innovative approach not only reuses the waste produced in the orange juice industry but also demonstrates the potential for obtaining environmentally friendly compounds.

关键词： Beverages Carbohydrates Fibers Polymers Soils

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Linear and nonlinear plasmonic effects modulated by a metalinsulator transition

Linear and nonlinear plasmonic effects modulated by a metali...

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IEEE/LEOS Winter Topical Meeting Series

作者： R. F. Haglund E. U. Donev L. C. Feldman D. W. Ferrara R. Lopez J. Y. Suh K.A. Tetz Department of Physics and Astronomy Interdisciplinary Graduate Program in Materials Science and Vanderbilt Institute for Nanoscale Science and Engineering Vanderbilt University Nashville TN USA Department of Physics and Astronomy and Department of Materials Science and Engineering Rutgers University Piscataway NJ USA Department of Physics and Astronomy and Institute for Advanced Materials Nanoscience and Technology North Carolina State University Chapel Hill NC USA

Localized and propagating plasmonic effects in noble-metal nanostructures are receiving worldwide attention as potential enabling principles for optical and electro-optic devices. A critical need in plasmonic device design is a general technique for active modulation of the plasmon response. In this paper, we describe the use of a reversible, solid-solid phase transition in VO 2 to modulate plasmonic response. Case studies are drawn from experiments on nano structured hole and particle arrays in which VO 2 acts as a modulator by altering the local dielectric constant.

关键词： Plasmons Optical devices Optical propagation Nanostructures Nonlinear optical devices Nonlinear optics Optical modulation Electrooptic devices Phase modulation Dielectric constant

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Biodegradable Pbat/Pla Blend Films Incorporated with Turmeric and Cinnamomum Powder: A Potential Alternative for Active Food Packaging

SSRN

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SSRN 2023年

作者： de Castro, Layara L.R.L. Abreu, Iago R. Braz, Cristiano J.F. Rodrigues, Samara C.S. dos Araújo, Regilda S.R.M. Folkersma, Rudy de Carvalho, Laura H. Barbosa, Renata Alves, Tatianny S. Graduate Program in Materials Science and Engineering Federal University of Piauí Teresina64.049-550 Brazil Department of Physics Federal Institute of Education Science and Technology of Piauí Teresina Central Campus Teresina64.000-040 Brazil Department of Nutrition Federal University of Piauí Teresina64.049-550 Brazil NHL Stenden University of Applied Sciences Groningen9727 Netherlands Graduate Program in Materials Science and Engineering Federal University of Campina Grande PI TeresinaCEP: 58.100-000 Brazil

Active packaging made from biodegradable polymers and natural additives appears as an ecological alternative. In addition to having antioxidant activity and enhancing food preservation, it allows mitigating the negative impacts caused by improper disposal. This study pursued to produce biodegradable films based on a polymer blend PBAT/PLA (Ecovio®) using the flat extrusion method. The films were prepared with the incorporation of 5 wt% of powdered turmeric or cinnamon as natural additives. The films obtained, and those reprocessed twice, were characterized in terms of colorimetric, UV light transmittance, water contact angle, water vapor permeability, morphology, mechanical properties, and antioxidant activity. Cinnamon reduced the UV light transmittance and made a surface more hydrophobic. Reprocessing led to greater elongation and maximum load, associated with increased dispersion and distribution, as evidenced in the morphological analysis. The films developed have significant potential for applications in active food packaging, with emphasis on cinnamon-additivated films. © 2023, The Authors. All rights reserved.

关键词： Biodegradable polymers

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A Robust Bendable Irox Thin Film Via Mild Alkaline Solution Process for Neuron Stimulating Electrodes

SSRN

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SSRN 2023年

作者： Tso, Kuang-Chih Chan, Tzu-Ying Yu, Tsung-Chun Pan, Shih-Chin Chu, Chao-Yi Chen, San-Yuan Lee, Jyh-Fu Ohta, Jun Wu, Pu-Wei Chen, Po-Chun Graduate Program of Accelerator Light Source National Yang Ming Chiao Tung University Hsinchu300 Taiwan Division of Materials Science Graduate School of Science and Technology Nara Institute of Science Technology Takayama Ikoma Nara8916-5 Japan Department of Materials Science and Engineering National Yang Ming Chiao Tung University Hsinchu300 Taiwan Institute of Materials Science and Engineering National Taipei University of Technology Taipei106 Taiwan National Synchrotron Radiation Research Center Hsinchu300 Taiwan

We demonstrate a unique chemical formula to deposit hydrous iridium oxide thin film on a platinum-coated polyimide substrate. In a mild alkaline solution, the iridium (III) precursor undergoes the ligand exchange and hydrolysis reaction to become the iridium (III) dimers that are physically adsorbed on the substrate for subsequent heterogeneous condensation and growth of amorphous hydrous iridium oxide thin film. Both UV-Vis and X-ray absorption spectroscopy (XAS) are employed to determine the reaction steps involved. The chemical nature and crystallinity of the hydrous iridium oxide thin film are investigated by XAS, X-ray photon spectroscopy, and X-ray diffraction. The hydrous iridium oxide thin film reveals an impressive normalized charge storage capacity (CSC) of 0.3 mC/cm2-nm and a low impedance (80.5 Ω) at 1k Hz. In addition, in bending test of 3,000 cycles, the hydrous iridium oxide thin film retains 91.2% of its initial normalized CSC without any physical crack and delamination. The cell viability test suggests negligible bio-toxicity. Our results provide a solid evidence of fabricating a robust flexible electrode for neural interfaces for potential use in implantable electronic devices. © 2023, The Authors. All rights reserved.

关键词： Iridium compounds

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Topology of three-dimensional Dirac semimetals and quantum spin Hall systems without gapless edge modes

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Physical Review Research 2023年第1期5卷 L012019-L012019页

作者： Alexander C. Tyner Shouvik Sur Danilo Puggioni James M. Rondinelli Pallab Goswami Graduate Program in Applied Physics Northwestern University Evanston Illinois 60208USA Department of Physics and Astronomy Northwestern University Evanston Illinois 60208 USA Department of Materials Science and Engineering Northwestern University Illinois 60208 USA Northwestern Argonne Institute for Science and Engineering Evanston Illinois 60208 USA

The quantum spin Hall states are usually expected to possess gapless, helical edge modes. We show that the generic, n-fold-symmetric, momentum planes of three-dimensional, stable Dirac semimetals, which are orthogonal to the direction of nodal separation are examples of generalized quantum spin Hall systems, that possess quantized, spin or relative Chern numbers as bulk topological invariants, and gapped edge modes. We demonstrate these planes and the celebrated Bernevig-Zhang-Hughes model support identical quantized, non-Abelian Berry flux of magnitude 2π. Hence, they display identical quantized, topological response such as spin-charge separation and pumping of one Kramers-pair or SU(2) doublet, when probed with a magnetic flux tube. The Dirac points are identified as unit-strength, monopoles of SO(5) Berry connection, describing topological phase transitions between generalized quantum spin Hall and trivial insulators. Our work identifies precise bulk invariant and quantized response of Dirac semimetals, which are not diagnosed by nested Wilson loops and filling anomaly of corner-localized-states, and shows that many two-dimensional higher-order topological insulators can be understood as generalized quantum spin Hall systems.

关键词： Fractionalization Geometric & topological phases Spintronics Topological insulators Topological phase transition Topological phases of matter

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