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Tailoring Mesoporous and Macroporous Structures in Activated Carbon from Naoh-Pretreated Oak for Superior Supercapacitors

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SSRN

SSRN 2024年

作者： Lim, Mu-Seong Kang, Seo Hui Song, Dae-Yeon Chae, Ji Su Lee, Jae-Won Lee, Younki Roh, Kwang Chul Energy Storage Materials Center Korea Institute of Ceramic Engineering and Technology Gyeongsangnam‑do Jinju-Si52851 Korea Republic of Department of Materials Engineering and Convergence Technology Gyeongsang National University 501 Jinju-daero Gyeongsangnam-do Jinju-Si52828 Korea Republic of Department of Materials Science and Engineering Korea University Anam-Dong Seongbuk-Gu Seoul136-713 Korea Republic of Department of Wood Science and Engineering College of Agriculture and Life Sciences Chonnam National University Gwangju61186 Korea Republic of Interdisciplinary Program in IT-Bio Convergence System Chonnam National University Gwangju61186 Korea Republic of

The growing need for sustainable and efficient energy storage solutions has intensified research efforts into eco-friendly materials such as activated carbon (AC) derived from lignocellulosic biomass. Herein, we present a method to enhance the physical characteristics of AC from oak via NaOH pretreatment. The NaOH-pretreated oak was converted into AC through carbonization and chemical activation using KOH as the activating agent. The AC tended to develop mesopores (2–50 nm) and macropores (> 50 nm) as the pretreatment ratio increased (0%, 1%, 2%, and 8%), achieving a specific surface area of up to 2706 m2 g–1 and a pore volume of up to 1.97 cm3 g–1. This result is due to the transformation of the structure of lignocellulosic biomass into a more advantageous structure for pore development through the reactions of delignification and deacetylation that occur during NaOH pretreatment. The mesoporous and macroporous structures offer efficient ion diffusion pathways and reduce resistance, which leads to superior rate capability, capacity retention, and a gravimetric specific capacitance of 44.5 F g–1 at a current density of 1 mA cm–2 in supercapacitors. These results underscore the potential of NaOH-pretreated oak as a sustainable and effective precursor for high-performance AC in energy storage applications, offering new insights into the optimization of material properties for supercapacitors. © 2024, The Authors. All rights reserved.

关键词： Lignocellulose

A Physics-Constrained Deep Learning Treatment of Runaway Electron Dynamics

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arXiv 2024年

作者： McDevitt, Christopher J. Arnaud, Jonathan Tang, Xian-Zhu Nuclear Engineering Program Department of Materials Science and Engineering University of Florida GainesvilleFL32611 United States Theoretical Division Los Alamos National Laboratory Los AlamosNM87545 United States

An adjoint formulation leveraging a physics-informed neural network (PINN) is employed to advance the density moment of a runaway electron (RE) distribution forward in time. A distinguishing feature of this approach is that once the adjoint problem is solved, its solution can be used to project the RE density forward in time for an arbitrary initial momentum space distribution of REs. Furthermore, by employing a PINN, a parametric solution to the adjoint problem can be learned. Thus, once trained, this adjoint-deep learning framework is able to efficiently project the RE density forward in time across various plasma conditions while still including a fully kinetic description of RE dynamics. As an example application, the temporal evolution of the density of primary electrons is studied, with particular emphasis on evaluating the decay of a RE population when below threshold. Predictions from the adjoint-deep learning framework are found to be in good agreement with a traditional relativistic electron Fokker-Planck solver, for several distinct initial conditions, and across an array of physics parameters. Once trained the PINN thus provides a means of generating RE density time histories with exceptionally low online execution time. © 2024, CC BY.

关键词： Fokker Planck equation

A Physics-Informed Deep Learning Description of Knudsen Layer Reactivity Reduction

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arXiv 2024年

作者： McDevitt, Christopher J. Tang, Xian-Zhu Nuclear Engineering Program Department of Materials Science and Engineering University of Florida GainesvilleFL32611 United States Theoretical Division Los Alamos National Laboratory Los Alamos NM87545 United States

A physics-informed neural network (PINN) is used to evaluate the fast ion distribution in the hot spot of an inertial confinement fusion target. The use of tailored input and output layers to the neural network is shown to enable a PINN to learn the parametric solution to the Vlasov-Fokker-Planck equation in the absence of any synthetic or experimental data. As an explicit demonstration of the approach, the specific problem of Knudsen layer fusion yield reduction is treated. Here, predictions from the Vlasov-Fokker-Planck PINN are used to provide a non-perturbative solution of the fast ion tail in the vicinity of the hot spot thus allowing the spatial profile of the fusion reactivity to be evaluated for a range of collisionalities and hot spot conditions. Excellent agreement is found between the predictions of the Vlasov-Fokker-Planck PINN and results from traditional numerical solvers with respect to both the energy and spatial distribution of fast ions and the fusion reactivity profile demonstrating that the Vlasov-Fokker-Planck PINN provides an accurate and efficient means of determining the impact of Knudsen layer yield reduction across a broad range of plasma conditions. © 2024, CC BY.

关键词： Deep learning

An Efficient Surrogate Model of Secondary Electron Formation and Evolution

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arXiv 2024年

This work extends the adjoint-deep learning framework for runaway electron (RE) evolution developed in Ref. [1] to account for large-angle collisions. By incorporating large-angle collisions the framework allows the avalanche of REs to be captured, an essential component to RE dynamics. This extension is accomplished by using a Rosenbluth-Putvinski approximation to estimate the distribution of secondary electrons generated by large-angle collisions. By evolving both the primary and multiple generations of secondary electrons, the present formulation is able to capture both the detailed temporal evolution of a RE population beginning from an arbitrary initial momentum space distribution, along with providing approximations to the saturated growth and decay rates of the RE population. Predictions of the adjoint-deep learning framework are verified against a traditional RE solver, with good agreement present across a broad range of parameters. © 2024, CC BY.

关键词： Electrons

Exchange-correlation potential built on the derivative discontinuity of electron density

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arXiv 2024年

作者： Huang, Chen Department of Scientific Computing Materials Science and Engineering Program National High Magnetic Field Laboratory Florida State University TallahasseeFL32306 United States

Electronic structures are fully determined by the exchange-correlation (XC) potential. In this work, we develop a new method to construct reliable XC potentials by properly mixing the exact exchange and the local density approximation potentials in real space. The spatially dependent mixing parameter is derived based on the derivative discontinuity of electron density and is first-principle. We derived the equations for solving the mixing parameter and proposed an approximation to simplify these equations. Based on this approximation, this new method gives reasonable predictions for the ionization energies, fundamental gaps, and singlet-triplet energy differences for various molecular systems. The impact of the approximation on the constructed XC potentials is examined, and it is found that the quality of the XC potentials can be further improved by removing the approximation. This work demonstrates that the derivative discontinuity of electron density is a promising constraint for constructing high-quality XC potentials. © 2024, CC BY.

关键词： Local density approximation

Lost-Core Injection Molding of Fluidic Elastomer Actuators for the Fabrication of a Modular Eel-Inspired Soft Robot

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Lost-Core Injection Molding of Fluidic Elastomer Actuators f...

IEEE International Conference on Soft Robotics (RoboSoft)

作者： Jacobo Cervera-Torralba Yuxiang Kang Eesa M. Khan Iman Adibnazari Michael T. Tolley Department of Mechanical and Aerospace Engineering University of California San Diego (UCSD) La Jolla CA USA Materials Science and Engineering Program University of California San Diego (UCSD) La Jolla CA USA

Biologically inspired soft anguilliform swimming robots show great promise in underwater exploration. Their soft bodies promise to reduce the chance of harming humans or wildlife with which they come into contact, and also to reduce their chance of becoming stuck in complex environments. Furthermore, the efficiency of anguilliform swimming may enable long duration operation. However, the design and fabrication of soft anguilliform swimming robots remain challenging. Here we present a design concept for a modular soft anguilliform robot. To address the challenge of consistently fabricating modules for this design, we also present a new fabrication method that combines injection molding and lost-core molding for the consistent fabrication of bi-directional fluidic elastomer actuator modules. We evaluate the consistency of the fabrication method through visual inspection, weight measurements, bending angle measurements and the measurement of force output of the actuator. This work represents a step towards an autonomous eel-inspired soft robot, as well as a new fabrication approach that may enable a number of other new soft robotic systems.

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Development of Flame Retardant Property on Sodium Silicate Treated Paper Based materials 21

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Development of Flame Retardant Property on Sodium Silicate T...

21st International Union of materials Research Societies International Conference in Asia, IUMRS-ICA 2021

作者： Suttipintu, Thitiporn Lhosupasirirat, Siraprapa Osotchan, Tanakorn Srikhirin, Toemsak Materials Science and Engineering Program School of Materials Science and Innovation Faculty of Science Mahidol University Bangkok10400 Thailand Research Network of NANOTEC Mahidol University National Nanotechnology Center Thailand Department of Physics Faculty of Science Mahidol University 272 Rama VI Road Ratchathewi District Bangkok10400 Thailand

The preparation of cellulose-based flame retardant paper treated with sodium silicate and silicon dioxide (SiO2) colloidal particle by simple immersion process is reported. Cellulose-based paper was preheated at 90°C for surface preparation. The heat treated paper was immersed in solution of sodium silicate-SiO2 at different immersion time ranging from 15 min to 24 hrs. Treated solution diffused into paper coated on the paper fiber and filled the void in the paper microstructure. Treated paper was heated at 90°C to convert an impregnated sodium silicate-SiO2 precursor into silicate framework. The treated paper showed Vsym Si-O-Si from siloxane bond at 792 cm-1 which confirmed a presence of SiO2 in paper. Treated paper at 1 hr immersion showed the highest weight percent gain (WPG) of 40% and total combustion time was improved to 14 sec. © Published under licence by IOP Publishing Ltd.

关键词： Silica

Injectable citrate-based polyurethane-urea as a tug-of-war-inspired bioactive self-expansive and planar-fixing screw augmented bone-tendon healing

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Bioactive materials 2024年第11期41卷 108-126页

作者： Meihan Tao Zhou Fang Yuting Zhu Yan Ju Zhiguo Hou Meimei Fu Zhihui Lu Daozhang Cai Jian Yang Jinshan Guo Department of Orthopedic Surgery Guangdong Provincial Key Laboratory of Bone and Joint Degeneration DiseasesThe Third Affiliated Hospital of Southern Medical UniversityGuangzhou510630PR China Department of Histology and Embryology NMPA Key Laboratory for Safety Evaluation of CosmeticsSchool of Basic Medical SciencesSouthern Medical UniversityGuangzhou510515PR China Regenerative Medicine and Tissue Repair Material Research Center Huangpu Institute of MaterialsGuangzhou New Materials Science CenterChangchun Institute of Applied ChemistryChinese Academy of Sciences88 Yonglong Avenue of Xinlong TownGuangzhou511363PR China Research Center for Industries of the Future Biomedical Engineering ProgramSchool of EngineeringWestlake UniversityHangzhouZhejiang310030PR China CAS Key Laboratory of High-Performance Synthetic Rubber and its Composite Materials Changchun Institute of Applied ChemistryChinese Academy of Sciences5625 Renmin StreetChangchun130022PR China

Inspired by tug-of-war,a game-changing bone-tendon fixation paradigm was ***,injectable citrate-based bioactive self-expansive and planar-fixing screw(iCSP-Scr)consisting of reactive isocyanate(NCO)terminalized citrate-based polyurethane,proanthocyanidin modified hydroxyapatite(HAp)and water(with/without porogen)was developed and administrated in the bone-tendon *** of the“point to point”tendon fixation by traditional interface screws,along with the moisture-induced crosslinking and expansion of iCSP-Scr within the confined space of the irregularly shaped bone-tendon gap,the tendon graft was evenly squeezed into the bone tunnel in a“surface to surface”manner to realize strong and stable bone-tendon fixation via physical expansion,mechanical interlocking and chemical bonding(between–NCO and the–NH2,–SH groups on bone matrix).The optimized iCSP-Scr exhibited rapid crosslinking,moderate expansion rate,high porosity after crosslinking,as well as tunable elasticity and *** iCSP-Scr possessed favorable biodegradability,biocompatibility,and osteoinductivity derived from citrate,PC and HAp,it was able to promote osteogenesis and new bone growth inward of bone tunnel thus further enhanced the bone/iCSP-Scr mechanical interlock,ultimately leading to stronger tendon fixation(pull-out force 106.15±23.15 N)comparing to titanium screws(93.76±17.89 N)after 14 weeks’ACL reconstruction in a rabbit *** iCSP-Scr not only can be used as a self-expansive screw facilitating bone-tendon healing,but also can be expanded into other osteogenic application scenarios.

关键词： Polyurethane Injectable Self-expansive Planar-fixing Citrate

Revisiting a hidden order at an ferromagnet/antiferromagnet interface and its switching dynamics

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Revisiting a hidden order at an ferromagnet/antiferromagnet ...

Magnetic Conference - Short Papers (INTERMAG Short Papers), IEEE International

作者： Chao-Yao Yang Sheng-Huai Chen Chih-Huang Lai Department of Materials Science and Engineering National Yang Ming Chiao Tung University Hsinchu Taiwan Undergraduate Degree Program of Systems Engineering and Technology National Yang Ming Chiao Tung University Hsinchu Taiwan Department of Materials Science and Engineering National Tsing Hua University Hsinchu Taiwan

Study on the exchange bias (H ex ) switching in a ferromagnet (FM)/antiferromagnet (AFM) bilayer driven by the spin-orbit torque (SOT) has been an explicit research field and current focus has been devoted to determining the approaches to drive the H ex switching along with specific SOT applications. H ex is magnetically dominant but only reveals the partial facet of IrMn, which is only responsible for the ferromagnetic component at the interface of AFM. Therefore, the complete facet of AFM and its interaction with SOT at an FM/AFM interface is still not fully uncovered. This research reports an SOT-driven hidden order transition behind H ex in a heavy metal (Pt)/FM (Co)/AFM (IrMn) trilayer along with the issue of switching activity at Co/IrMn interface. The exchange coupling across Co/IrMn interface allows a long-range spin order in the form of an exchange-spring configuration, yielding two kinds of order in IrMn: a canting-induced ferromagnetic order for hosting H ex and a hidden Néel order for preserving the antiferromagnetic nature. The former appears to be strongly coupled to the magnetization state of Co during the SOT switching, so it can be reversibly switched with Co on the H ex switching. On the contrary, the hidden Néel order transition re-orientated to the current direction appears to be irreversibly driven by SOT and independent on the current polarity, which can reflect on the magnetoresistance (MR) measurement and X-ray magnetic linear dichroism (XMLD) spectroscopy. Finally, a micromagnetic simulation reveals the dynamic IrMn spins are mainly based on a canting type interface instead of an uncompensated type via an exchange-spring coupling with Co.

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