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Influence of submerged arc welding slag content variation on cementitious materials: A sustainable alternative

Construction and Building Materials 2025年 483卷

作者： Castro-Lopes, S. Rodrigues, V.D. Marden, Sandro Peña-Garcia, R. Padrón-Hernández, E. Berenguer, Romildo Federal Institute of Education Science and Technology of Pará PA Altamira Brazil Laboratory of Composite Materials and Structural Integrity Corrosion and Biocorrosion - CompoLab/LBC Federal University of Pernambuco PE Recife Brazil Federal University of Paraiba Department of Mechanical Engineering PB Joao Pessoa Brazil Federal Rural University of Pernambuco Postgraduate Program in Physics Engineering Academic Unit of Cabo de Santo Agostinho Cabo de Santo PE Agostinho Brazil Federal University of Pernambuco Department of Physics PE Recife Brazil Polytechnic School University of Pernambuco PE Recife Brazil Federal University of Pernambuco Department of Mechanical Engineering PE Recife Brazil

This study evaluates the effects of submerged arc welding (SAW) slag as a partial replacement for Portland cement in cementitious materials. Cement pastes with 5 %, 10 %, 15 %, 20 %, 25 %, and 30 % SAW slag were tested for compressive strength, tensile strength, carbonation resistance, phase formation, and environmental impact. The results revealed that up to 10 % SAW slag significantly enhanced compressive strength, with the 5 % replacement showing a 20.10 % increase in strength at 28 days compared to the control. The mechanical improvement was attributed to the formation of the CSH phase, which was confirmed by X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Carbonation tests indicated that the 5 % SAW samples reduced carbonation by 5 % compared to the control, while the 10 % SAW samples showed a 1 % reduction. This suggests that SAW slag enhances the resistance of cementitious materials to CO2 attack, improving long-term durability. XRD analysis also identified an increase in amorphous phases in the SAW samples, particularly in the 5 % addition, further supporting the pozzolanic activity of SAW slag. Pozzolanic effectiveness coefficient analysis revealed synergistic effects for SAW slag blends, with optimal performance observed at 5 % replacement, in line with microstructural evidence of enhanced CSH gel formation. Environmental analysis demonstrated that replacing 10 % of Portland cement with SAW slag could reduce CO2 emissions by approximately 4564 kg annually, while a 15 % replacement could lead to a reduction of 6846 kg of CO2. These results underscore the potential of SAW slag as a sustainable and performance-enhancing alternative to conventional cement in concrete production. © 2025 Elsevier Ltd

关键词： Compressive strength

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Computational Characterization of the Recently Synthesized Pristine and Porous 12-Atom-Wide Armchair Graphene Nanoribbon

arXiv

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arXiv 2025年

作者： da Gomes, Djardiel S. Felix, Isaac M. Radel, Willian F. Dias, Alexandre C. Ribeiro Junior, Luiz A. Pereira Junior, Marcelo L. State University of Campinas Gleb Wataghin Institute of Physics Department of Applied Physics Campinas São Paulo13083-859 Brazil University of Brasília Faculty UnB Planaltina Materials Science Postgraduate Program Federal District Brasília Brazil Center for Agri-food Science and Technology Federal University of Campina Grande Paraíba Pombal58840-000 Brazil University of Brasília Institute of Physics Physics Postgraduate Program Federal District Brasília70910900 Brazil Institute of Physics International Center of Physics University of Brasília Federal District Brasília70910-900 Brazil Institute of Physics University of Brasília Federal District Brasília70910-900 Brazil Computational Materials Laboratory University of Brasília Federal District Brasília70910900 Brazil University of Brasília College of Technology Department of Electrical Engineering Federal District Brasília70910-900 Brazil

Recently synthesized Porous 12-Atom-Wide Armchair Graphene Nanoribbons (12-AGNRs) [Nano Lett. 2024, 24, 10718-10723]exhibit tunable properties through periodic porosity, enabling precise control over their electronic, optical, thermal, and mechanical behavior. This work presents a comprehensive theoretical characterization of pristine and porous 12-AGNRs based on density functional theory (DFT) and molecular dynamics (MD) simulations. DFT calculations reveal substantial electronic modifications, including band gap widening and the emergence of localized states. Analyzed within the Bethe–Salpeter equation (BSE) framework, optical properties highlight strong excitonic effects and significant absorption shifts. Thermal transport simulations indicate a pronounced reduction in conductivity due to enhanced phonon scattering at nanopores. At the same time, MD-based mechanical analysis shows decreased stiffness and strength while maintaining structural integrity. Despite these modifications, porous 12-AGNRs remain mechanically and thermally stable. These findings establish porosity engineering as a powerful strategy for tailoring graphene nanoribbons’ functional properties, reinforcing their potential for nanoelectronic, optoelectronic, and thermal management *** Codes 00-xx © 2025, CC BY.

关键词： Nanoribbons

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Supplementary information for "Low-loss silicon nitride Kerr-microresonators fabricated with metallic etch masks via metal lift-off"

arXiv

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arXiv 2025年

作者： Colación, Gabriel M. Rukh, Lala Buck, Franco Drake, Tara E. Optical Science & Engineering Program University of New Mexico AlbuquerqueNM87106 United States Center for High Technology Materials University of New Mexico AlbuquerqueNM87106 United States Department of Physics & Astronomy University of New Mexico AlbuquerqueNM87106 United States

Stoichiometric silicon nitride has emerged as a widely used integratedphotonic material owing to its high index of refraction, nonlinear opticalproperties, and broad transparency window spanning visible to mid-IRfrequencies. However, silicon nitride is generally more resistant to reactiveion etching than are typical etch masks made of polymer-based resist. Thisnecessitates resist layers that are significantly thicker than the siliconnitride and results in mask patterns which are tall and narrow. Thesehigh-aspect-ratio patterns inhibit the plasma transport of reactive ionetching, which leads to difficulties in accurately reproducing dimensions andcreating well-defined, vertical waveguide sidewalls. In this work, we overcomethese challenges by developing a metallic etch mask that provides a 30:1nitride-to-metal etch rate ratio, representing a near 20-fold reduction in therequired mask thickness. We demonstrate the quality of this technique byetching microring resonators with near-vertical waveguide sidewalls andintrinsic quality factors of over 1 million. Leveraging the low optical loss ofour resonators, we generate optical frequency combs with more than an octave ofbandwidth and dual dispersive waves. These results establish metal lift-off asa viable and easy-to-implement technique capable of producing low optical losswaveguides. © 2025, CC BY.

关键词： Aspect ratio

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BPS2025 - Cell-cell communication patterns in growing tissues

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Biophysical Journal 2025年第3期124卷 302a-302a页

作者： Abdul Malmi Kakkada Jonathan Dawson Physics and Biophysics Program Augusta University Augusta GA USA Department of Engineering and Physics Whitworth University Spoken WA USA

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AN INVESTIGATION OF NEUTRAL-BEAM-DRIVEN IMPURITY FLOW REVERSAL AS AN IMPURITY CONTROL METHOD IN FUTURE TOKAMAKS

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NUCLEAR SCIENCE AND engineering 1984年第4期88卷 475-485页

作者： BENNETT, RB STACEY, WM Georgia Inst of Technology Nuclear Engineering & Health Physics Program Atlanta GA USA Georgia Inst of Technology Nuclear Engineering & Health Physics Program Atlanta GA USA

A theory for the effect of directed neutral beam injection (NBI) on impurity transport in tokamaks is extended to include temperature gradient effects. The extended theory is compared with experimental data from the Princeton Large Torus, and certain coefficients are adjusted to provide agreement. The adjusted theory is applied to assess the potential of NBI being used to prevent impurities from penetrating to the center of future tokamak plasmas, thereby possibly creating a cold radiating edge. The results indicate the possibility of creating a cold radiating edge in the tokamak fusion test reactor and in future tokamaks represented by the fusion engineering device and STARFIRE.

关键词： TOKAMAK DEVICES

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Coupling metal and support clusters dictates the reactivity of Ru catalysts for ammonia synthesis

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Chemical engineering Science 2025年 312卷

作者： Zhang, Tianhua Zhang, Yangyu Chen, Zuo-Chang Qiu, Yujue Zhang, Mingyuan Zhang, Shiyong Peng, Xuanbei Zhang, Lei Zhou, Yanliang Zheng, Lirong Xu, Bo-Qing Wang, Xiuyun Jiang, Lilong National Engineering Research Center of Chemical Fertilizer Catalyst Fuzhou University Fujian 350002 China Qingyuan Innovation Laboratory Fujian Quanzhou362801 China State Key Laboratory of Physical Chemistry of Solid Surfaces National Engineering Laboratory for Green Chemical Production of Alcohols-Ethers-Esters iChEM College of Chemistry and Chemical Engineering Xiamen University Xiamen China Institute of High Energy Physics Chinese Academy of Sciences Beijing100049 China Innovative Catalysis Program Key Lab of Organic Optoelectronics & Molecular Engineering Department of Chemistry Tsinghua University Beijing100084 China

Strong metal-support interaction (SMSI) is a crucial strategy for modulating the activity. Finely tailoring the size of the support to the nanoscale still faces significant challenges. Herein, for the first time, C60 carbon cluster is utilized as a nano-support to anchor ultrafine Ru nanoclusters to create a Ru-C60 cluster–cluster co-catalyst. The unique geometric structure of the nano-support C60 enables the construction of a strong cluster–cluster interaction (SCCI), quite different from traditional SMSI. La-modified Ru-C60 presents a surprising discovery that NH3 can even be synthesized at 150 °C, and exhibits an unprecedentedly high NH3 synthesis rate at 400 °C. C60 not only acts as an electron buffer to balance the charge density of Ru sites, but also stabilizes more metallic Ru active sites with a smaller size due to its spatial and SCCI effect, thereby achieving superior catalytic performance over a wide range of temperatures and pressures. © 2025 Elsevier Ltd

关键词： Nanoclay

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A ghost mechanism: An analytical model of abrupt learning

arXiv

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arXiv 2025年

作者： Dinc, Fatih Cirakman, Ege Jiang, Yiqi Yuksekgonul, Mert Schnitzer, Mark Tanaka, Hidenori CNC Program Stanford University StanfordCA94305 United States Physics & Informatics Laboratories NTT Research Inc. SunnyvaleCA94085 United States Stanford University StanfordCA94305 United States James H. Clark Center for Biomedical Engineering & Sciences Stanford University Stanford United States Howard Hughes Medical Institute Stanford University StanfordCA94305 United States CBS-NTT Program in Physics of Intelligence Harvard University CambridgeMA94305 United States

Abrupt learning is commonly observed in neural networks, where long plateaus in network performance are followed by rapid convergence to a desirable solution. Yet, despite its common occurrence, the complex interplay of task, network architecture, and learning rule has made it difficult to understand the underlying mechanisms. Here, we introduce a minimal dynamical system trained on a delayed-activation task and demonstrate analytically how even a one-dimensional system can exhibit abrupt learning through ghost points rather than bifurcations. Through our toy model, we show that the emergence of a ghost point destabilizes learning dynamics. We identify a critical learning rate that prevents learning through two distinct loss landscape features: a no-learning zone and an oscillatory minimum. Testing these predictions in recurrent neural networks (RNNs), we confirm that ghost points precede abrupt learning and accompany the destabilization of learning. We demonstrate two complementary remedies: lowering the model output confidence prevents the network from getting stuck in no-learning zones, while increasing trainable ranks beyond task requirements (i.e., adding sloppy parameters) provides more stable learning trajectories. Our model reveals a bifurcation-free mechanism for abrupt learning and illustrates the importance of both deliberate uncertainty and redundancy in stabilizing learning dynamics. © 2025, CC BY.

关键词： Recurrent neural networks

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Observation of mechanical kink control and generation via phonons

arXiv

引用

arXiv 2025年

作者： Qian, Kai Cheng, Nan Serafin, Francesco Sun, Kai Theocharis, Georgios Mao, Xiaoming Boechler, Nicholas Department of Mechanical and Aerospace Engineering University of California San Diego La Jolla CA92093 United States Department of Physics University of Michigan Ann ArborMI48109 United States Department of Physics and Materials Science University of Luxembourg 2 Avenue de l’Universite L Esch-sur-Alzette4365 Luxembourg CNRS Le Mans Université France Program in Materials Science and Engineering University of California San Diego La Jolla CA92093 United States

Kinks (or domain walls) are localized transitions between distinct ground states associated with a topological invariant, and are central to many phenomena across physics, from condensed matter to cosmology. While phonon (i.e., small-amplitude vibration) wave packets have been theorized to deterministically interact with kinks and initiate their movement, this interaction has remained elusive in experiments, where only uncontrollable stochastic kink motion generated by thermal phonons or dislocation glide by low-frequency quasi-static loading have been observed. This is partly because all physical systems that support kinks are, at some level, discrete, making deterministic phonon control of kinks extremely challenging due to the existence of Peierls-Nabarro (PN) barrier. Here, we demonstrate, for the first time, experimental observation of phonon-mediated control and generation of mechanical kinks, which we enable using a topological metamaterial that constitutes an elastic realization of the Kane-Lubensky chain model. Our metamaterial overcomes the PN barrier by supporting a single, topologically protected kink that requires zero energy to form and move. Using simulations that show close agreement with our experimental observations, we also reveal unique dynamics of phonon interplay with highly discrete kinks, including long-duration motion and a continuous family of internal modes, features absent in other discrete nonlinear systems. This work introduces a new paradigm for topological kink control, with potential applications in material stiffness tuning, shape morphing, locomotion, and robust signal transmission. © 2025, CC BY-NC-ND.

关键词： Stochastic systems

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Rare Earths and Magnetic Refrigeration

引用

Journal of Rare Earths 2006年第6期24卷 641-647页

作者： Karl A Gschneidner Vitalij K Pecharsky Materials and Engineering Physics Program Ames Laboratory and Department of Materials Science and Engineering Iowa State University Ames Iowa USAJr. Materials and Engineering Physics Program Ames Laboratory and Department of Materials Science and Engineering Iowa State University Ames Iowa USA

Magnetic refrigeration is a revolutionary, efficient, environmentally friendly cooling technology, which is on the threshold of commercialization. The magnetic rare earth materials are utilized as the magnetic refrigerants in most cooling devices, and for many cooling application the Nd2Fe14B permanent magnets are employed as the source of the magnetic field. The status of the near room temperature magnetic cooling was reviewed.

关键词： magnetic refrigeration magnetocaloric effect gadolinium Gd5 （ Si1- x Gex ） 4 La （ Fe 13 - x Six ） Hy Nd2 Fe14 B permanent magnets active magnetic regenerator cycle rare earths

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Spin pumping mechanism in Py/SnTe bilayers: An approach through the magnetoimpedance effect

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Journal of Alloys and Compounds 2025年 1031卷

作者： de Morais, A. Souza, E.C. de Silva, A.L. Gamino, M. da Silva, E.F. Ferreira, A. Vaz, F. Lopes, C. Bohn, F. Correa, M.A. Postgraduate Program in Materials Science and Engineering Federal University of Rio Grande do Norte RN Natal 59078-970 Brazil Physics Department Federal University of Rio Grande do Norte RN Natal 59075-000 Brazil Physics Department Federal University of Pernambuco PE Recife 50670-901 Brazil Physics Centre of Minho and Porto Universities (CF-UM-UP) University of Minho 4710-057 Portugal LaPMET - Laboratory of Physics for Materials and Emergent Technologies University of Minho 4710-057 Portugal

Different techniques addressing magnetization dynamics are helpful to estimate parameters of a ferromagnetic thin film nanostructure in the field of spintronics, including Gilbert damping parameter (α_G), spin pumping contributions (α_SP), two magnons scattering (α_TMS), spin mixing conductance (G_eff) and others. When considering a bilayer structure, the non-ferromagnetic layer effects need to be carefully selected to tailor an effective spintronic response. Here, the magnetization dynamics are explored in Ni₈₁Fe₁₉(Py)/Ag and Ni₈₁Fe₁₉(Py)/SnTe nanostructures and report the spin mixing conductance from magnetoimpedance experiments. The results are interpreted by considering structural and magnetic characterizations. The spin mixing conductance is estimated as G_eff (Py/Ag) = 1.13×10¹⁴ cm⁻² and G_eff (Py/SnTe) = 18.05 ×10¹⁴ cm⁻², revealing the significant enhancement of G_eff when the SnTe acts as a cap layer, indicating that SnTe is a good spin sink. © 2025 Elsevier B.V.

关键词： Damping mechanisms Magnetoimpedance SnTe Spin pumping Spintronics

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