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SSRN 2023年

作者： Wahab, Md. Abdul Karim, Mohammad Rezaul Al-Mubaddel, Fahad S. Sindan, A. Will, Geoffrey Abdala, Ahmed Nanomaterials Centre Australian Institute for Bioengineering and Nanotechnology The University of Queensland St Lucia BrisbaneQLD4072 Australia Energy and Process Engineering Division School of Mechanical Medical and Process Engineering Science and Engineering Faculty Queensland University of Technology 2 George Street QLD4001 Australia Chemical Engineering Program Texas A and M University Education City Doha Qatar King Saud University Riyadh11421 Saudi Arabia K.A. CARE Energy Research and Innovation Center King Saud University Riyadh11451 Saudi Arabia Chemical Engineering Department King Saud University PO Box 800 Riyadh11421 Saudi Arabia

This study investigates synergistic effects of Fe nanoparticles (FeNPs) supported on mesoporous carbon (MC) for catalyzing hydrogen storage properties of Mg(BH4)2 (MBH). The study compares two methods for dispersing Fe NPs in MC: (i) ultrasonication nanoconfinement (un) and (ii) postnanoconfinement (pn) via stirring. Based on the results, it is found that the ultrasonication nanoconfinement method can effectively disperse the FeNPs with 5 nm in MC support (FeNP-unMC), later which can efficiently confine MBH (FeNP-un-MC@MBH system). The hydrogen (H2) desorption properties of the FeNP-un-MC@MBH system were found to be better than that of postconfinement-mediated FeNP-pn-MC@MBH system. For instance, H2 started to desorb from the FeNP-un-MC@MBH system at only 66°C (Tonset) and reached its peak at ~153°C, compared to 270°C (Tonset) and its peak ~350°C for pure MBH, respectively. The ultrasonication-mediated nanoconfined FeNP-un-MC@MBH system released a total of 7.01 wt% H2 within 90 minutes at 350°C. The study shows that the activation energy (Ea) of FeNP-un-MC@MBH is 19.57 kJ/mol, achieved due to the improved dehydrogenation kinetics of MBH. These improvements are due to the synergistic effects of nano-compartmentalization and highly dispersed Fe NP catalyst sites in the MC support. The research emphasizes the promising application of ultrasonication-mediated nanoconfined Fe NPs in mesoporous carbon which can be used as an effective catalyst for enhancing the hydrogen storage properties of metal-based hydrides (MBH). © 2023, The Authors. All rights reserved.

关键词： Hydrogen storage

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DATA-DRIVEN MORI-ZWANZIG: REDUCED ORDER MODELING OF SPARSE SENSORS MEASUREMENTS FOR BOUNDARY LAYER TRANSITION

arXiv

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arXiv 2023年

作者： Woodward, Michael Tian, Yifeng Mohan, Arvind Lin, Yen Ting Hader, Christoph Fasel, Hermann Chertkov, Michael Livescu, Daniel Computer Computational and Statistical Sciences Division Los Alamos National Laboratory Los AlamosNM87544 United States Graduate Interdisciplinary Program in Applied Mathematics Department of Mathematics University of Arizona TucsonAZ85721 United States Department of Aerospace and Mechanical Engineering University of Arizona TucsonAZ85721 United States

Understanding, predicting and controlling laminar-turbulent boundary-layer transition is crucial for the next generation aircraft design. However, in real flight experiments, or wind tunnel tests, often only sparse sensor measurements can be collected at fixed locations. Thus, in developing reduced models for predicting and controlling the flow at the sensor locations, the main challenge is in accounting for how the surrounding field of unobserved (or unresolved) variables interacts with the observed (or resolved) variables at the fixed sensor locations. This makes the Mori-Zwanzig (MZ) formalism a natural choice, as it results in the Generalized Langevin Equations which provides a mathematically sound framework for constructing non-Markovian reduced-order models that include the effects the unresolved variables have on the resolved variables. These effects are captured in the so called memory kernel and orthogonal dynamics, which, when using Mori's linear projection, provides a higher order approximation to the traditional approximate Koopman learning methods. In this work, we explore recently developed data-driven methods for extracting the MZ operators to two boundary-layer flows obtained from high resolution data;a low speed incompressible flow over a flat plate exhibiting bypass transition;and a high speed compressible flow over a flared cone at Mach 6 and zero angle of attack where transition was initiated using a broadband forcing approach ("natural" transition). In each case, an array of "sensors" are placed near the surface of the solid boundary, and the MZ operators are learned and the predictions are compared to the Extended Dynamic Mode Decomposition (EDMD), both using delay embedded coordinates. Further comparisons are made with Long Short-Term Memory (LSTM) and a regression based projection framework using neural networks for the MZ operators. First, we compare the effects of including delay embedded coordinates with EDMD and Mori based MZ and provide

关键词： Dynamic mode decomposition

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Designing the pressure-dependent shear modulus using tessellated granular metamaterials

arXiv

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arXiv 2023年

作者： Zhang, Jerry Wang, Dong Jin, Weiwei Xia, Annie Pashine, Nidhi Kramer-Bottiglio, Rebecca Shattuck, Mark D. O’Hern, Corey S. Department of Mechanical Engineering & Materials Science Yale University New HavenCT06520 United States Benjamin Levich Institute and Physics Department The City College of New York New YorkNY10031 United States Department of Physics Yale University New HavenCT06520 United States Department of Applied Physics Yale University New HavenCT06520 United States Integrated Graduate Program in Physical and Engineering Biology Yale University New HavenCT06520 United States

Jammed packings of granular materials display complex mechanical response. For example, the ensemble-averaged shear modulus 〈G〉 increases as a power-law in pressure p for static packings of soft spherical particles that can rearrange during compression. We seek to design granular materials with shear moduli that can either increase or decrease with pressure without particle rearrangements even in the large-system limit. To do this, we construct tessellated granular metamaterials by joining multiple particle-filled cells together. We focus on cells that contain a small number of bidisperse disks in two dimensions. We first study the mechanical properties of individual disk-filled cells with three types of boundaries: periodic boundary conditions (PBC), fixed-length walls (FXW), and flexible walls (FLW). Hypostatic jammed packings are found for cells with FLW, but not in cells with PBC and FXW, and they are stabilized by quartic modes of the dynamical matrix. The shear modulus of a single cell depends linearly on p. We find that the slope of the shear modulus with pressure, λc c > 0, as well as λc © 2023, CC BY.

关键词： Elastic moduli

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Carbon footprint of coffee production: the case study of Indian Robusta coffee

Energy Nexus

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Energy Nexus 2025年 18卷

作者： Iglesias, Sandra P. Karka, Paraskevi Posada, John A. Lindeboom, Ralph E.F. Broek, Machteld van den Gopi, Girigan Mathew, Manju John, T.D. Champatan, Vipin Aravind, P.V. Energy Conversion Group Energy and Sustainability Research Institute Groningen Faculty of Science and Engineering University of Groningen Nijenborgh 6 Groningen 9747AG Netherlands Engineering and Technology Institute Groningen Faculty of Science and Engineering University of Groningen Nijenborgh 3 Groningen 9747AG Netherlands Department of Biotechnology Delft University of Technology Building 58 Van der Maasweg 9 HZ Delft 2629 Netherlands Universidad ECCI Postgraduate Department Bogotá 111311 Colombia CITG Section Sanitary Engineering Department of Water Management Faculty of Civil Engineering and Geosciences Delft Stevinweg 1 CN Delft 2628 Netherlands Delft University of Technology Faculty of Technology Policy and Management Jaffalaan 5 BX Delft 2628 Netherlands MS Swaminathan Research Foundation India Climate Smart Coffee Program- KDISC India Mechanical Engineering Dept Govt. Engg. College Wayanad Kerala India

Coffee processing encompasses the conversion of coffee cherries into marketable products, including the removal of outer layers to produce green coffee and, in extended chains, their roasting into roasted coffee, and grinding into ground coffee. Calculating the carbon footprint (CF) in coffee processing is crucial for identifying and mitigating key sources of greenhouse gas (GHG) emissions. Utilizing the Life Cycle Assessment (LCA) methodology, the current study quantifies the CF associated with Robusta dry coffee processing by collecting primary data through interviews with coffee producers and visits to coffee processing units, roasting, and grinding facilities in Wayanad, India. The study identifies GHG emission hotspots across two scenarios. Scenario A includes transportation of dried coffee beans from farm to coffee processing unit, green coffee production, packaging, roasting, and grinding at a local unit, while Scenario B covers local transportation of green coffee beans from India to The Netherlands, green coffee production, packaging, and its transportation from India to The Netherlands. Cultivation and harvesting of coffee cherries, consumer-level preparation and use, and disposal of coffee products are outside the scope of this study. The functional unit is defined as 1 kg of green coffee for both scenarios. Findings show that the CF equals 0.62 and 0.38 kg CO_2eq per kg of green coffee for scenarios A and B, respectively. Roasting (78 % of CF), and sea transportation (66 % of CF) emerged as the main hotspots of GHG emissions for scenario A, and scenario B, respectively. © 2025 The Author(s)

关键词： Carbon footprint Green coffee Ground coffee LCA Roasted coffee Robusta coffee

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Mori–Zwanzig Modal Decomposition

arXiv

引用

arXiv 2023年

作者： Woodward, Michael Tian, Yifeng Lin, Yen Ting Hader, Christoph Fasel, Hermann Livescu, Daniel Graduate Interdisciplinary Program in Applied Mathematics Department of Mathematics University of Arizona TucsonAZ85721 United States Computer Computational and Statistical Sciences Division Los Alamos National Laboratory Los AlamosNM87544 United States Department of Aerospace and Mechanical Engineering University of Arizona TucsonAZ85721 United States

We introduce the Mori-Zwanzig (MZ) Modal Decomposition (MZMD), a novel technique for performing modal analysis of large scale spatio-temporal structures in complex dynamical systems, and show that it represents an efficient generalization of Dynamic Mode Decomposition (DMD). The MZ formalism provides a mathematical framework for constructing non-Markovian reduced-order models of resolved variables from high-dimensional dynamical systems, incorporating the effects of unresolved dynamics through the memory kernel and orthogonal dynamics. We present a formulation and analysis of the modes and spectrum from MZMD and compare it to DMD when applied to a complex flow: a Direct Numerical Simulation (DNS) data-set of laminar-turbulent boundary-layer transition flow over a flared cone at Mach 6. We show that the addition of memory terms by MZMD improves the resolution of spatio-temporal structures within the transitional/turbulent regime, which contains features that arise due to nonlinear mechanisms, such as the generation of the so-called "hot" streaks on the surface of the flared cone. As a result, compared to DMD, MZMD improves future state prediction accuracy, while requiring nearly the same computational cost. Copyright © 2023, The Authors. All rights reserved.

关键词： Dynamic mode decomposition

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Diopside-based Bioactive Glass-Ceramic Nanoparticles for Osteoimmunomodulation

引用

Ceramics International 2025年

作者： Sun Latt Pedram Sotoudehbagha Valeria Cardenas Andres Larraza Mehdi Razavi Biionix (Bionic Materials Implants & Interfaces) Cluster Department of Medicine University of Central Florida College of Medicine Orlando FL 32827 USA Burnett School of Biomedical Sciences University of Central Florida College of Medicine Orlando FL 32827 USA Department of Materials Science and Engineering University of Central Florida Orlando FL 32816 USA Biomedical Engineering Program Department of Mechanical and Aerospace Engineering University of Central Florida Orlando Florida 32816 USA

The objective of this study was to develop and characterize an osteoimmunomodulatory diopside-based glass-ceramic nanoparticle synthesized using a sol-gel synthesis method. Hydroxyapatite nanoparticles were utilized as a gold standard control. X-ray diffraction, transmission electron microscopy, scanning electron microscopy equipped with energy dispersive spectroscopy, dynamic light scattering, and zeta-potential analysis were performed to characterize the crystalline phase, morphology, microstructure, composition, hydrodynamic size distribution, and surface charge, respectively. Weight loss, pH, and ion release were measured after immersion of glass-ceramic nanoparticles in simulated body fluid to evaluate the nanoparticle’s biodegradation, showing ranges of Ca 2+ , Mg 2+ , and Si 4+ ion release previously found to be osteogenic and angiogenic. Cytocompatibility with human bone-marrow-derived mesenchymal stem cells and murine RAW264.7 macrophages was studied using metabolic activity (MTT) and live/dead fluorescent assays, demonstrating dose-dependent cytotoxicity in RAW264.7 cells and excellent biocompatibility with mesenchymal stem cells. The effect of the nanoparticles on M1/M2 macrophage polarization potential was evaluated through ELISA and phase-contrast image analysis. Our glass-ceramic nanoparticle promoted greater M2-associated anti-inflammatory IL-1ra cytokine release than M1-associated pro-inflammatory TNF-α release compared to hydroxyapatite nanoparticles, though significant morphological changes were not observed. These results indicate that our glass-ceramic nanoparticle is a promising osteoimmunomodulatory biomaterial for bone regenerative applications.

关键词： Stem cells

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Time dependence of nickel-coated st60 steel corrosion rate in sulfuric acid media

Time dependence of nickel-coated st60 steel corrosion rate i...

引用

2019 International Conference on Renewable Energy, ICORE 2019

作者： Muhtadi, I. Puspitasari, P. Aminnudin, A. Permanasari, A.A. Sukarni, S. Pratama, M.M.A. Putra, A.B.N.R. Postgraduate Program Department of Mechanical Engineering State University of Malang Semarang Street Malang Indonesia Department of Mechanical Engineering State University of Malang Semarang Street Malang Indonesia Center of Advanced Materials and Renewable Energy State University of Malang Semarang Street Malang Indonesia Civil Engineering Department State University of Malang Semarang Street Malang Indonesia

The low-carbon steel alloy (St60 steel) consists of steel (Fe) and elements such as carbon (C), silicon (Si), manganese (Mn), phosphor (P), and others. This research aimed to analyze the corrosion rate of steel St. 60 by nickel coating in a corrosion test using 4M concentrated H2SO4 (sulfuric acid) with soaking solution for 60 minutes, 120 minutes, 180 minutes, and 240 minutes respectively. This research obtained by weighing the samples to find the weight losses after corrosion which resulted of 31.8 mg, 104.0 mg, 318.1 mg, and 575.4 mg for samples in 60 minutes, 120 minutes, 180 minutes, and 240 minutes soaking duration respectively. The corrosion rate calculation showed relatively significant weight losses. The average weight loss from the specimens in soaking time of 60 minutes, 120 minutes, 180 minutes, and 240 minutes were 0.0203 mm/year, 0.0320 mm/year, 0.0642 mm/year, and 0.0893 mm/year. The highest corrosion rate process was found in the soaking duration of 240 minutes, with the value of 0.0893 mm/year. The significant weight loss meant that soaking duration greatly influences the corrosion rate with the conclusion of longer duration resulted in a high corrosion rate and vice versa. © Published under licence by IOP Publishing Ltd.

关键词： Corrosion rate

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AgriField3D: A Curated 3D Point Cloud and Procedural Model Dataset of Field-Grown Maize from a Diversity Panel

arXiv

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arXiv 2025年

作者： Kimara, Elvis Hadadi, Mozhgan Godbersen, Jackson Balu, Aditya Jubery, Talukder Li, Yawei Krishnamurthy, Adarsh Schnable, Patrick S. Ganapathysubramanian, Baskar Department of Computer Science Iowa State University Ames United States Translational AI Research and Education Center Ames United States Department of Mechanical Engineering Iowa State University Ames United States Plant Science Institute Iowa State University Ames United States Interdepartmental Genetics and Genomics Graduate Program Iowa State University Ames United States Department of Agronomy Iowa State University Ames United States

The application of artificial intelligence (AI) in three-dimensional (3D) agricultural research, particularly for maize, has been limited by the scarcity of large-scale, diverse datasets. While 2D image datasets are abundant, they fail to capture essential structural details such as leaf architecture, plant volume, and spatial arrangements that 3D data provide. To address this limitation, we present AgriField3D (website), a curated dataset of 3D point clouds of field-grown maize plants from a diverse genetic panel, designed to be AI-ready for advancing agricultural research. Our dataset comprises over 1,000 high-quality point clouds collected using a Terrestrial Laser Scanner, complemented by procedural models that provide structured, parametric representations of maize plants. These procedural models, generated using Non-Uniform Rational B-Splines (NURBS) and optimized via a two-step process combining Particle Swarm Optimization (PSO) and differentiable programming, enable precise, scalable reconstructions of leaf surfaces and plant architectures. To enhance usability, we performed graph-based segmentation to isolate individual leaves and stalks, ensuring consistent labeling across all samples. We also conducted rigorous manual quality control on all datasets, correcting errors in segmentation, ensuring accurate leaf ordering, and validating metadata annotations. The dataset further includes metadata detailing plant morphology and quality, alongside multi-resolution subsampled versions (100k, 50k, 10k points) optimized for various computational needs. By integrating point cloud data of field grown plants with high-fidelity procedural models and ensuring meticulous manual validation, AgriField3D provides a comprehensive foundation for AI-driven phenotyping, plant structural analysis, and 3D applications in agricultural research. © 2025, CC BY-NC-SA.

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Role of Zn in tuning the structural, morphological and optical properties of V 2 O 5 nanostructures deposited by spray pyrolysis

引用

Materials Today: Proceedings 2021年 35卷 469-473页

作者： Sandesh Kumar Rai Rajesh Rai Raghavendra Bairy M.S. Murari A. Jayarama Richard Pinto Department of Mechanical Engineering Canara Engineering College Mangalore 574219 India Regional Research Center Visvesvaraya Technological University Belagav 590 018 India Department of Mechanical Engineering AJ Institute of Engineering and Technology Mangalore 575006 India Department of Physics NMAM Institute of Technology (Visvesvaraya Technological University Belagavi) Nitte Karkala 574110 India DST PURSE Program Mangalore University Mangalagangothri 574199 India Department of Physics Alva’s Institute of Engineering and Technology Moodbidri 574225 India Department of Electronics and Communication Engineering Alva’s Institute of Engineering and Technology Moodbidri 574225 India

Venadium Pentoxide (V 2 O 5 ) thin films were deposited by employing a spray pyrolysis technique on glass substrates at 573 K for different Zn-doping levels (0, 1, 3, 5 and 10 wt%) to study the optical, structural and morphological properties of pure and Zn-doped V 2 O 5 thin films. The characterisation study with powder X-ray diffraction confirms the orthorhombic structure and also that the films grow along (2 0 0) direction with increase in the doping concentration. The Scherer rule was employed to determine the crystallite size and found to be enhanced. Field Emission Scanning Electron Microscopy study reveals that the surface morphology modifications increase with Zn-doping. The surface topography of the prepared films was also studied using AFM and found to be enhanced. The optical energy band gap (Eg) of the prepared films was found to be varying between 3.27 eV and 3.72 eV due to increase in doping concentration. The interesting results of structural and optical parameters with the increase in Zn-doping concentration suggest that these nanostructured films are a promising material for opto-electronic device applications.

关键词： Zn-doped V 2 O 5 thin films Spray pyrolysis Energy band gap XRD FESEM Photon energy Surface morphology

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mechanical Plasticity of Cell Membranes Enhances Epithelial Wound Closure

arXiv

引用

arXiv 2023年

作者： Ton, Andrew T. MacKeith, Arthur K. Shattuck, Mark D. O'Hern, Corey S. Department of Physics Yale University New HavenCT06520 United States Integrated Graduate Program in Physical and Engineering Biology Yale University New HavenCT06520 United States Department of Mechanical Engineering & Materials Science Yale University New HavenCT06520 United States Benjamin Levich Institute and Physics Department The City College of New York New YorkNY10031 United States Department of Applied Physics Yale University New HavenCT06520 United States

During epithelial wound healing, cell morphology near the healed wound and the healing rate vary strongly among different developmental stages even for a single species like Drosophila. We develop deformable particle (DP) model simulations to understand how variations in cell mechanics give rise to distinct wound closure phenotypes in the Drosophila embryonic ectoderm and larval wing disc epithelium. We find that plastic deformation of the cell membrane can generate large changes in cell shape consistent with wound closure in the embryonic ectoderm. Our results show that the embryonic ectoderm is best described by cell membranes with an elasto-plastic response, whereas the larval wing disc is best described by cell membranes with an exclusively elastic response. By varying the mechanical response of cell membranes in DP simulations, we recapitulate the wound closure behavior of both the embryonic ectoderm and the larval wing disc. © 2023, CC BY-NC-ND.

关键词： Cytology

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