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Bayesian optimization with active learning of design constraints using an entropy-based approach

npj Computational materials 2023年第1期9卷 1866-1879页

作者： Danial Khatamsaz Brent Vela Prashant Singh Duane D.Johnson Douglas Allaire Raymundo Arróyave J.Mike Walker’66 Department of Mechanical Engineering Texas A&M UniversityCollege StationTX 77843USA Department of Materials Science and Engineering Texas A&M UniversityCollege StationTX 77843USA Ames Laboratory U.S.Department of EnergyIowa State UniversityAmesIA 50011USA Department of Materials Science&Engineering Iowa State UniversityAmesIA 50011USA Department of Industrial and Systems Engineering Texas A&M UniversityCollege StationTX 77843USA

The design of alloys for use in gas turbine engine blades is a complex task that involves balancing multiple objectives and *** alloys must be ductile at room temperature and retain their yield strength at high temperatures,as well as possess low density,high thermal conductivity,narrow solidification range,high solidus temperature,and a small linear thermal expansion *** Integrated Computational materials engineering(ICmE)methods are not sufficient for exploring combinatorially-vast alloy design spaces,optimizing for multiple objectives,nor ensuring that multiple constraints are *** this work,we propose an approach for solving a constrained multi-objective materials design problem over a large composition space,specifically focusing on the mo-Nb-Ti-V-W system as a representative multi-Principal Element Alloy(mPEA)for potential use in next-generation gas turbine *** approach is able to learn and adapt to unknown constraints in the design space,making decisions about the best course of action at each stage of the *** a result,we identify 21 Pareto-optimal alloys that satisfy all *** proposed framework is significantly more efficient and faster than a brute force approach.

关键词： alloys solidification alloy

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A GRAPH ALGORITHm FOR THE DESIGN OF FUNCTIONALLY GRADED ALLOY COmPONENTS

A GRAPH ALGORITHM FOR THE DESIGN OF FUNCTIONALLY GRADED ALLO...

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ASmE 2024 International Design engineering Technical Conferences and Computers and Information in engineering Conference, IDETC-CIE 2024

作者： Allen, marshall D. Arróyave, Raymundo malak, Richard Mechanical Engineering Texas A&M University College StationTX United States Materials Science and Engineering Texas A&M University College StationTX United States

ISBN: (纸本)9780791888360

One of the promising capabilities of metal additive manufacturing (Am) is the potential to manufacture metal parts with spatially varying alloy compositions. It is hypothesized that these compositionally graded alloy (CGA) parts can satisfy competing cost and performance requirements that cannot be met with a monolithic alloy. However, there are significant challenges in their design and manufacture, such as the formation of deleterious material phases and solidification cracking during Am. Prior work addresses the materials design of CGAs between two alloy targets in trivial geometries. However, there are no formal approaches to designing complex CGA parts, limiting the application of these promising materials for further research and implementation. In current practice, most manufactured CGAs are unidirectional, with composition changing in planar, cylindrical, or spherical layers. In this paper, we introduce a novel graph-based algorithm for designing manufacturable general CGA components. Given a component geometry with two or more alloy composition targets at select locations, the algorithm uses a labeled property graph representation of material compatibilities and properties to generate a valid alloy gradient throughout the entire part. We show that the algorithm will always find an alloy gradient solution if one exists, demonstrate it on subsea valve body design problem using the Fe-Ni-Cr ternary system, and study the algorithm’s scalability concerning several key problem discretization parameters. Copyright © 2024 by ASmE.

关键词： Iron alloys

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Corrosion behavior of mg-Zn-Zr-RE alloys under physiological environment-Impact on mechanical integrity and biocompatibility

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Journal of magnesium and Alloys 2022年第6期10卷 1542-1572页

作者： marwa AbdelGawad Chaudhry A.Usman Vasanth C.Shunmugasamy Ibrahim Karaman Bilal mansoor Mechanical Engineering Program Texas A&M University at QatarEducation CityDoh1Qatar Department of Mechanical Engineering Texas A&M University3123 TAMUCollege StationTX 77843United States of America Department of Materials Science and Engineering Texas A&M University3003 TAMUCollege StationTX 77843United States of America

Benefits of RE addition on mg alloys strength and corrosion resistance are widely reported but their effects on biodegradability and biocompatibility are still of *** paper investigates the effect of RE additions on biodegradability of mg-Zn alloys under simulated physiological *** this context,two commercial mg-Zn-Zr-RE alloys,namely ZE41 and EZ33,with same RE addition but different concentrations are studied in Hank’s Balanced Salt Solution(HBSS)at 37℃and with pH of ***-loss,hydrogen evolution,real-time insitu drop test,electrochemical impedance spectroscopy(EIS)and potentiodynamic polarization are deployed to study corrosion *** mechanical integrity of both alloys is assessed by mechanical testing post ***,in vitro biocompatibility is evaluated by indirect cytotoxicity tests using NIH3T3 *** reveal that although both alloys showed similar microstructure,size and distribution of precipitates played a significant role on its corrosion *** and open circuit potential results show stable film formation on EZ33,while ZE41 showed passive layer formation followed by its deterioration,over the analyzed time *** real-time drop test,it was shown in ZE41 alloy that both T-phase and Zr-rich precipitates acted as micro cathodes,resulting in an unstable surface *** EZ33,Zr-rich regions did not influence corrosion response,resulting in better corrosion resistance that was corroborated by post-immersion surface morphology *** higher degradation observed in ZE41 alloy resulted in higher drop in flexural and tensile strength compared to EZ33 *** addition,cytotoxicity tests on NIH3T3 cells revealed that cell viability of EZ33 increased with increasing incubation time,contrary to ZE41,owing to its lower biodegradation behavior and despite higher concentrations of *** results show that an increase in RE concentration in EZ33,relative to ZE41,had a positive effect on

关键词： magnesium alloy Corrosion EIS mechanical integrity Cytotoxicity

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In vitro and in vivo study on fine-grained mg-Zn-RE-Zr alloy as a biodegradeable orthopedic implant produced by friction stir processing

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Bioactive materials 2023年第10期28卷 448-466页

作者： Vasanth C.Shunmugasamy marwa AbdelGawad muhammad Umar Sohail Talal Ibrahim Talha Khan Thomas Daniel Seers Bilal mansoor Mechanical Engineering Program Texas A&M University at QatarEducation CityDohaQatar Department of Mechanical Engineering Texas A&M University3123 TAMUCollege StationTX 77843USA Proteomics Core Weill Cornell MedicineEducation CityDohaQatar Department of Surgery Division of Orthopedic SurgerySidra MedicineDohaQatar Clinical Orthopedic Surgery Weill Cornell MedicineEducation CityDohaQatar Petroleum Engineering Program Texas A&M University at QatarEducation CityDohaQatar Department of Materials Science and Engineering Texas A&M University3003 TAMUCollege StationTX 77843USA

magnesium alloys containing biocompatible components show tremendous promise for applications as temporary biomedical devices. However, to ensure their safe use as biodegradeable implants, it is essential to control their corrosion rates. In concentrated mg alloys, a microgalvanic coupling between the α-mg matrix and secondary precipitates exists which results in increased corrosion rate. To address this challenge, we engineered the microstructure of a biodegradable mg-Zn-RE-Zr alloy by friction stir processing (FSP), improving its corrosion resistance and mechanical properties simultaneously. The FS processed alloy with refined grains and broken and uniformly distributed secondary precipitates showed a relatively uniform corrosion morphology accompanied with the formation of a stable passive layer on the alloy surface. In vivo corrosion evaluation of the processed alloy in a small animal model showed that the material was well-tolerated with no signs of inflammation or harmful by-products. Remarkably, the processed alloy supported bone until it healed till eight weeks with a low in vivo corrosion rate of 0.7 mm/year. moreover, we analyzed blood and histology of the critical organs such as liver and kidney, which showed normal functionality and consistent ion and enzyme levels, throughout the 12- week study period. These results demonstrate that the processed mg-Zn-RE-Zr alloy offers promising potential for osseointegration in bone tissue healing while also exhibiting controlled biodegradability due to its engineered microstructure. The results from the present study will have profound benefit for bone fracture management, particularly in pediatric and elderly patients.

关键词： Biodegradable magnesium Bone healing Friction stir processing microstructure Corrosion resistance

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Hydrogen bonded polymer complex thin films for highly stretchable gas barriers

RSC Applied Polymers

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RSC Applied Polymers 2024年第3期2卷 356-364页

作者： Fisher, Sarah G. Chiang, Hsu-Cheng Iverson, Ethan T. Chang, Edward Grunlan, Jaime C. Department of Chemistry Texas A&M University College Station 77843 TX United States Department of Mechanical Engineering Texas A&M University College Station 77843 TX United States Department of Materials Science & Engineering Texas A&M University College Station 77843 TX United States

Clay-containing polyelectrolyte complexes have been investigated as simple and effective gas barrier coatings for a variety of substrates. Some applications for barrier coatings, such as stretchable electronics, require films that exhibit high extensibility as well as low oxygen transmission rate. This combination of properties is difficult to achieve, as barrier tends to go hand-in-hand with film density. In this work, a stretchable thin film with low oxygen transmission rate (OTR) was prepared through the addition of montmorillonite (mmT) clay into a hydrogen bonded complex of poly(ethylene oxide) (PEO) and poly(acrylic acid) (PAA). Interpolymer hydrogen bonding and mmT clay distribution were found to improve with an increasing ratio of PEO to PAA in the complex, leading to the creation of a highly stretchable coating with a high gas barrier. This elastomeric system, deposited in three steps on 760 μm thick natural rubber, reduces the OTR by two orders of magnitude with a thickness of 1.8 μm. This film maintains a >90% reduction in OTR even after it is subjected to 50% strain. This is believed to be the first gas barrier coating deposited as a buffer-cured, hydrogen bonded polymer complex. © 2024 RSC.

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Virtual modeling and Evaluation of Scratch Visibility Resistance of Textured Polymeric Surfaces

Virtual Modeling and Evaluation of Scratch Visibility Resist...

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SPE Annual Technical Conference and Exhibition, ANTEC 2024

作者： Khatri, Sumit Sue, Hung-Jue Department of Materials Science and Engineering Polymer Technology Center Texas A&M University TX United States

ISBN: (纸本)9798331308193

Polymeric materials are in widespread usage across various industries owing to their lightweight, processability, adaptability, and cost-effectiveness. However, their vulnerability to scratches has long been a persistent concern. To address this challenge, application of designed surface texture to polymer surfaces is one of the most cost-effective means to improve the scratch resistance. These textures depend on both the control of contact attributes through the reduction of surface friction and obscuring the appearance of scratches. Currently, evaluation of a specific texture effectiveness in resisting scratches requires a combination of psychophysical and instrumental testing for scratch visibility. In this article, we have implemented a scratch visibility analysis scheme based on virtual reality, along with finite element method-generated simulated scratches. This approach takes into account material, topographical, and optical attributes to reproduce the perceived visibility of scratches. Usefulness of the above approach for timely and cost-effective production of scratch resistant polymers is discussed. © 2024 Society of Plastics Engineers. All rights reserved.

关键词： Scratch resistance

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Controlling the morphology of 2D Laser-induced Periodic Surface Structures (LIPSS) for Surface-enhanced Raman Spectroscopy applications 19

Controlling the morphology of 2D Laser-induced Periodic Surf...

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Laser-based micro- and Nanoprocessing XIX 2025

作者： Baskar, Balaji Ahad, Atiqul Islam Berrospe-Rodriguez, Carla Aguilar, Guillermo J. Mike Walker’66 Department of Mechanical Engineering Texas A&M University College Station United States Department of Materials Science & Engineering Texas A&M University College Station United States

ISBN: (纸本)9781510684508

The creation of laser-induced periodic surface structures (LIPSS) with near-submicron dimensions has significantly altered the surface properties of materials, as demonstrated in the past decade. These properties, particularly the hydrophobic characteristics, can be enhanced when combined with the dense nanostructures in LIPSS, making them ideal for highly sensitive surface-enhanced Raman spectroscopy (SERS) applications. However, a key challenge lies in precisely controlling the morphology of these nanostructures and their surface contact properties to effectively concentrate analyte molecules in specific regions for detection at extremely low concentrations. Here we show how single and double femtosecond laser pulse irradiation can be used to achieve different LIPSS morphologies. We generate 1D and 2D periodic nanostructures on 304 stainless steel substrates by adjusting the polarization and inter-pulse delay between fs pulses. From the preliminary experimental results, the dense hotspots in these LIPSS-based sensors allow for the detection of Rhodamine 6G at concentrations as low as 10-10 m, with an analytical enhancement factor of 2 × 107 for consistent and repeatable measurements. These findings provide important insights into the control of laser-induced submicron morphologies by adjusting experimental parameters, offering a straightforward and cost-efficient approach for detecting molecules at ultra-trace levels. © 2025 SPIE.

关键词： Femtosecond lasers

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Practical prescribed-time fuzzy tracking control for uncertain nonlinear systems with time-varying actuators faults

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Journal of Automation and Intelligence 2024年第1期3卷 40-49页

作者： Shuxing Xuan Hongjing Liang Tingwen Huang College of Automation Engineering University of Electronic Science and Technology of ChinaChengdu 611731China Science Program Texas A&M UniversityDoha 23874Qatar

The paper investigates the practical prescribed-time fuzzy tracking control problem for a category of nonlinear system subject to time-varying actuator *** presence of unknown nonlinear dynamics and actuator faults makes achieving tracking control within a prescribed-time *** tackle this issue,we propose a novel practical prescribed-time fuzzy tracking control strategy,which is independent of the initial state of the system and does not rely on precise modeling of the system and *** apply the approximation capabilities of fuzzy logic systems to handle the unknown nonlinear functions and unidentified actuator faults in the *** piecewise controller and adaptive law constructed based on piecewise prescribed time-varying function and backstepping technique method establish the theoretical framework of practical prescribed-time tracking control,and extend the range of prescribed-time tracking control to *** of the initial conditions,the proposed control strategy can guarantee that all signals remain uniformly bounded within the practical prescribed time in the presence of unknown nonlinear item and time-varying actuator *** example is presented to demonstrate the effectiveness of the proposed control strategy.

关键词： Prescribed-time tracking control Adaptive fuzzy control Actuator faults Uncertain nonlinear system

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Pixelated Directional Thermal Emitter

Pixelated Directional Thermal Emitter

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2024 Conference on Lasers and Electro-Optics/Pacific Rim, CLEO-PR 2024

作者： Fan, Ziwei Hwang, Taeseung Lin, Sam Chen, Yixin Wong, Zi Jing Department of Aerospace Engineering Texas A&M University College Station United States Department of Materials Science and Engineering Texas A&M University College Station United States School of Electronic Science and Technology Eastern Institute of Technology Ningbo China

Through the utilization of non-imaging optical principles, we have successfully demonstrated a pixelated micro-emitter that achieves ultrabroadband, polarization-independent directional control of thermal radiation. The designed architecture enables high emissivity contrasts at different viewing angles. Leveraging the tunable angular range of the pixelated micro-emitter, we create an infrared display that contains information encoded directionally. © 2024 The Author(s)

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Phosphorescence Lifetime Imaging for monitoring an Insertable Hydrogel multianalyte Sensor 46

Phosphorescence Lifetime Imaging for Monitoring an Insertabl...

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46th Annual International Conference of the IEEE engineering in medicine and Biology Society, EmBC 2024

作者： Ko, Brian Serivuth Pradhan, Ridhi mcShane, michael J. Texas A&m University Department of Biomedical Engineering College Station United States Texas A&m University Center for Remote Health Technologies and Systems Department of Biomedical Engineering Department of Materials Science & Engineering College Station United States

ISBN: (纸本)9798350371499

Oxidoreductase enzymes paired with oxygen-sensitive phosphorescent dyes can be immobilized in sensor structures that allow for continuous monitoring following insertion with minimal insult to the tissue. However, oxidoreductase-based sensors are limited by their consumption of oxygen, requiring knowledge and control of local oxygen conditions. Further, oxygen-responsive phosphors also exhibit temperature dependence. In this paper, we present a novel sensor design capable of providing glucose measurements while also reporting local oxygen and temperature variations. The sensor was composed of a miniature hydrogel multicompartment device containing phosphorescent sensing assays for glucose, oxygen, and temperature. The sensor was monitored using phosphorescence lifetime time-gated imaging using a custom system. The sensor response to buffer solutions of varying glucose (0, 100, 200, 400 mg/dL), oxygen (0-210 μm), and temperature (32, 37, 42 C) was collected. The lifetime measured from the sensor compartments was found to correlate closely with the Stern-Volmer relationship for luminescence response to changing oxygen concentration. This demonstrates feasibility of a multianalyte sensor platform, laying the foundation for development of tools for minimally-invasive simultaneous monitoring of multiple *** Relevance: Chronic conditions such as diabetes can benefit greatly from continuous monitoring. Oxidoreductase sensing of analytes such as glucose is highly sensitive, highly specific, and well established, but may be affected by local oxygen and temperature variations. In this paper, we present a sensor design that can compensate for environmental fluctuations and improve accuracy, all within a minimally invasive form factor. © 2024 IEEE.

关键词： chronic diseases continuous analyte monitoring optical multiplexing

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