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Synthesis investigation and exploring of new tetraglycidyl bisurea bisphenyl S polyepoxide as an excellent corrosion inhibitory resin for mild steel in 1M HCl environment: Comprehensive approaches

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Journal of Molecular Liquids 2024年 416卷

作者： Azogagh, M. El Magri, A. Hsissou, R. Lachhab, R. Katin, Konstantin P. Berdimurodov, Elyor Galai, M. Hegazi, S.E. Rafik, M. Laboratory of Organic Chemistry Catalysis Environment Department of Chemistry Faculty of Sciences Ibn Tofail University BP 242 Kenitra14000 Morocco Sultan Moulay Slimane University Laboratory of Materials Science Mathematics and Environment Polydisciplinary Faculty Khouribga Morocco Laboratory of Organic Chemistry Bioorganic and Environment Chemistry Department Faculty of Sciences Chouaib Doukkali University BP 20 El Jadida24000 Morocco Laboratory of Advanced Materials and Process Engineering Faculty of Sciences Ibn Tofail University BP 242 Kenitra14000 Morocco National Research Nuclear University "MEPhI" Kashirskoe Shosse 31 Moscow115409 Russia Chemical & Materials Engineering New Uzbekistan University 54 Mustaqillik Ave. Tashkent100007 Uzbekistan University of Tashkent for Applied Sciences Str. Gavhar 1 Tashkent100149 Uzbekistan Department of Physical Chemistry National University of Uzbekistan Tashkent100034 Uzbekistan

This work reports the synthesis of new epoxy resin namely tetraglycidyl bisurea bisphenyl S (TGBUBS). TGBUBS was characterized through using nuclear magnetic resonance (1H NMR and 13C NMR) and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). TGBUBS was investigated as an excellent organic inhibitor for protecting the mild steel from corrosion in 1M HCl solution at different concentrations. Anticorrosion protection behaviors were evaluated and more discussed including different techniques such as potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and contact angle (CA) measurements. The obtained results showed that the TGBUBS exhibited inhibition efficiencies at lower concentration are 93.19 % (PDP) and 91.21 % (EIS), respectively. Further, PDP measurements indicated that the TGBUBS acted as a mixed-type inhibitor in 1M HCl solution. Furthermore, SEM and EDS analysis showed a significant reduction in the corrosion on the mild steel surface when the inhibitory epoxy resin was present compared to the blank solution (1M HCl). The effectiveness and interactions of the new epoxy resin on the mild steel surface were also predicted using DFT calculations and molecular dynamics (MD) simulations. The theoretical approaches are in agreement with the experiment results. © 2024 Elsevier B.V.

关键词： Energy dispersive spectroscopy

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On the approximability of random-hypergraph MAX-3-XORSAT problems with quantum algorithms

arXiv

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arXiv 2023年

作者： Kapit, Eliot Barton, Brandon A. Feeney, Sean Grattan, George Patnaik, Pratik Sagal, Jacob Carr, Lincoln D. Oganesyan, Vadim Department of Physics Colorado School of Mines 1523 Illinois St GoldenCO80401 United States Department of Applied Mathematics and Statistics Colorado School of Mines 1500 Illinois St GoldenCO80401 United States Quantum Engineering Program Colorado School of Mines 1523 Illinois St GoldenCO80401 United States Department of Physics and Astronomy College of Staten Island CUNY Staten IslandNY10314 United States Physics Program and Initiative for the Theoretical Sciences The Graduate Center CUNY New YorkNY10016 United States Center for Computational Quantum Physics Flatiron Institute 162 5th Avenue New YorkNY10010 United States

A canonical feature of the constraint satisfaction problems in NP is approximation hardness, where in the worst case, finding sufficient-quality approximate solutions is exponentially hard for all known methods. Fundamentally, the lack of any guided local minimum escape method ensures both exact and approximate classical approximation hardness, but the equivalent mechanism(s) for quantum algorithms are poorly understood. For algorithms based on Hamiltonian time evolution, we explore this question through the prototypically hard MAX-3-XORSAT problem class. We conclude that the mechanisms for quantum exact and approximation hardness are fundamentally distinct. We review known results from the literature, and identify mechanisms that make conventional quantum methods (such as Adiabatic Quantum Computing) weak approximation algorithms in the worst case. We construct a family of "spectrally filtered" quantum algorithms that escape these issues, and develop analytical theories for their performance. We show that, for random hypergraphs in the approximation-hard regime, if we define the energy to be E = Nunsat - Nsat, spectrally filtered quantum optimization will return states with E ≤ qmEGS (where EGS is the ground state energy) in sub-quadratic time, where conservatively, qm 0.59. This is in contrast to qm → 0 for the hardest instances with classical searches. We test all of these claims with extensive numerical simulations. We do not claim that this approximation guarantee holds for all possible hypergraphs, though our algorithm’s mechanism can likely generalize widely. These results suggest that quantum computers are more powerful for approximate optimization than had been previously assumed. © 2023, CC BY.

关键词： Constraint satisfaction problems

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Additive average Schwarz method for elliptic mortar finite element problems with highly heterogeneous coefficients

arXiv

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arXiv 2021年

作者： Khademi, Ali Marcinkowski, Leszek Acharya, Sanjib Kumar Rahman, Talal Department of Computer science Electrical engineering and Mathematical sciences Western Norway University of Applied Sciences P.O. Box 7030 Bergen Norway Department of Mathematics Warsaw University Poland Institute of Chemical Technology Mumbai Indian Oil Campus Odisha Bhubaneswar India

In this paper, we extend the additive average Schwarz method to solve second order elliptic boundary value problems with heterogeneous coefficients inside the subdomains and across their interfaces by the mortar technique, where the mortar finite element discretization is on nonmatching meshes. In this two-level method, we enrich the coarse space in two different ways, i.e., by adding eigenfunctions of two variants of the generalized eigenvalue problems. We prove that the condition numbers of the systems of algebraic equations resulting from the extended additive average Schwarz method, corresponding to both coarse spaces, are of the order O(H/h) and independent of jumps in the coefficients, where H and h are the mesh *** Codes 65N55, 65F10, 65N25, 65N30 © 2021, CC BY-NC-ND.

关键词： Domain decomposition methods

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Topological defect-propelled swimming of nematic colloids

arXiv

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arXiv 2021年

作者： Yao, Tianyi Kos, Žiga Luo, Yimin Steager, Edward B. Ravnik, Miha Stebe, Kathleen J. Chemical and Biomolecular Engineering University of Pennsylvania PhiladelphiaPA19104 United States Department of Mathematics Massachusetts Institute of Technology CambridgeMA02139 United States Faculty of Mathematics and Physics University of Ljubljana Jadranska 19 Ljubljana1000 Slovenia Department of Chemical Engineering University of California Santa BarbaraCA93106 United States Mechanical Engineering and Applied Mechanics University of Pennsylvania PhiladelphiaPA19104 United States Condensed Matter Physics Department J. Stefan Institute Jamova 39 Ljubljana1000 Slovenia

Non-equilibrium dynamics of topological defects can be used as a fundamental propulsion mechanism in microscopic active matter. Here, we demonstrate swimming of topological defect-propelled colloidal particles in (passive) nematic fluids through experiments and numerical simulations. Dynamic swim strokes of the topological defects are driven by colloidal rotation in an external magnetic field, causing periodic defect rearrangement which propels the particles. The swimming velocity is determined by the colloid's angular velocity, sense of rotation and defect polarity. By controlling them we can locomote the particles along different trajectories. We demonstrate scattering - that is, the effective pair interactions - of two of our defect-propelled swimmers, which we show is highly anisotropic and depends on the microscopic structure of the defect stroke, including the local defect topology and polarity. More generally, this work aims to develop biomimetic active matter based on the underlying relevance of topology. Copyright © 2021, The Authors. All rights reserved.

关键词： Defects

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Computational fluid dynamics analysis of hybrid foam-mat freeze drying process

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AIP Conference Proceedings 2024年第1期2991卷

作者： Retno Wulandari Evi Susanti Melisa Surya Andini Bagus Anggoro Dwicahyo Arvin Dwi Nanda Mechanical Engineering Department Faculty of Engineering Universitas Negeri Malang Semarang Street No. 5 Malang 65145 Jawa Timur Indonesia Biotechnology Program Department of Applied Science Faculty of Mathematics and Natural Science Universitas Negeri Malang Semarang Street No. 5 Malang 65145 Jawa Timur Indonesia

To produce halal, safe, and affordable food collagen are factors that need to be resolved in food processing industry. Collagen was made from milkfish scales and B. megaterium TR-10. Freeze drying method has been around for a long time and usually use in food processing, including collagen production. Freeze drying techniques need in this separation of protein and water as a solvent due addition of acetone and NaCl so that the protein has not to denaturation due to processing above 50ᵒC. Computational method to simulate heat and mass transfer freeze drying in the collagen formation at -60ᵒC with a pressure less than 10 Pa to obtain optimal efficiency. When compared to conventional dryers, hybrid freeze dryers excel in several key areas: drying efficiency, energy efficiency, moisture removal procedure, product quality, and nutrient or bioactive ingredient preservation. The simulation using a foam mat with variation 1mm, 3mm, and 5mm. Changing product into a foam to expand the surface area and mass transfer increase thus drying process take a short time. This simulation begins with designing use Ansys R21 and the next process is numerical calculations to analyze heat and mass transfer in freeze drying process to obtain optimal efficiency result. The optimal value is obtained because effectiveness heat and mass transfer process when the collagen converted into foam causing surface largen with thinnest layers. Drying time with hybrid technique is between 1/4 to 1/7 times faster compared non-foam drying.

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Iterative quantum optimization of spin glass problems with rapidly oscillating transverse fields

arXiv

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arXiv 2024年

作者： Barton, Brandon Sagal, Jacob Feeney, Sean Grattan, George Patnaik, Pratik Oganesyan, Vadim Carr, Lincoln D. Kapit, Eliot Quantum Engineering Program Colorado School of Mines 1523 Illinois St GoldenCO80401 United States Department of Applied Mathematics and Statistics Colorado School of Mines 1500 Illinois St GoldenCO80401 United States Center for Computational Quantum Physics Flatiron Institute 162 5th Avenue New YorkNY10010 United States Department of Physics Colorado School of Mines 1523 Illinois St GoldenCO80401 United States Department of Computer Science Colorado School of Mines 1500 Illinois St GoldenCO80401 United States Department of Physics and Astronomy College of Staten Island City University of New York Staten IslandNY10314 United States Physics program and Initiative for the Theoretical Sciences The Graduate Center City University of New York New YorkNY10016 United States

In this work, we introduce a new iterative quantum algorithm, called Iterative Symphonic Tunneling for Satisfiability problems (IST-SAT), which solves quantum spin glass optimization problems using high-frequency oscillating transverse fields. IST-SAT operates as a sequence of iterations, in which bitstrings returned from one iteration are used to set spin-dependent phases in oscillating transverse fields in the next iteration. Over several iterations, the novel mechanism of the algorithm steers the system toward the problem ground state. We benchmark IST-SAT on sets of hard MAX-3-XORSAT problem instances with exact state vector simulation, and report polynomial speedups over trotterized adiabatic quantum computation (TAQC) and the best known semi-greedy classical algorithm. When IST-SAT is seeded with a sufficiently good initial approximation, the algorithm converges to exact solution(s) in a polynomial number of iterations. Our numerical results identify a critial Hamming radius(CHR), or quality of initial approximation, where the time-to-solution crosses from exponential to polynomial scaling in problem size. By combining IST-SAT with future classical or quantum approximation algorithms, larger gains may be achieved. The mechanism we present in this work thus presents a new path toward achieving quantum advantage in optimization. © 2024, CC BY.

关键词： Combinatorial optimization

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Quasiclassical approach to quantum quench dynamics in the presence of an excited-state quantum phase transition

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Physical Review A 2021年第3期103卷 032213-032213页

作者： Michal Kloc Daniel Šimsa Filip Hanák Petra Ruth Kaprálová-Žďánská Pavel Stránský Pavel Cejnar Department of Physics University of Basel Klingelbergstrasse 82 CH-4056 Basel Switzerland Institute of Particle and Nuclear Physics Faculty of Mathematics and Physics Charles University V Holešovičkách 2 Prague 18000 Czech Republic Department of Radiation and Chemical Physics Institute of Physics Academy of Sciences of the Czech Republic Na Slovance 2 182 21 Prague 8 Czech Republic Applied Physics Department of Engineering Sciences and Mathematics Luleå University of Technology 97187 Luleå Sweden

The dynamics of a quantum system following a sudden, highly nonadiabatic change of its control parameter (quantum quench) is studied with quasiclassical techniques. Recent works have shown, using exact quantum mechanical approach, that equilibration after quantum quench exhibits specific features in the presence of excited-state quantum phase transitions. In this paper, we demonstrate that these features can be understood from the classical evolution of the Wigner function in phase space.

关键词： Quantum phase transitions Quantum quench Dicke model Semiclassical methods Tavis-Cummings model

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Halving interval guaranteed for Dekker and Brent root finding methods

Examples and Counterexamples

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Examples and Counterexamples 2024年 7卷

作者： Steffen, Vilmar Pasqua, Carlos Catusso Della de Oliveira, Maiquiel Schmidt da Silva, Edson Antonio Academic Departments of Engineering (DAENG) Federal University of Technology - Parana (UTFPR) Rua Gelindo Joao Folador 2000 Parana Francisco Beltrao 85602-863 Brazil Chemical Engineering Corse Federal University of Technology - Parana (UTFPR) Rua Gelindo Joao Folador 2000 Parana Francisco Beltrao 85602-863 Brazil Academic Department of Physics Statistics and Mathematics (DAFEM) Federal University of Technology - Parana (UTFPR) Rua Gelindo Joao Folador 2000 Parana Francisco Beltrao 85602-863 Brazil Center for Engineering and Exact Sciences (CECE) State University of Paraná (Unioeste) Rua da Faculdade 645 Parana Toledo 85903-000 Brazil Postgraduate Program in Chemical Engineering State University of Paraná (Unioeste) Rua da Faculdade 645 Parana Toledo 85903-000 Brazil

Hybrid methods are widely used in many areas of applied mathematics. One of the simplest and most common problems in this field is root finding, for which various methods exist. Some of the most efficient approaches combine two or more techniques into hybrid methods. Among these are the Dekker and Brent methods, for which we propose a modification to ensure that the search interval is halved in each iteration. We apply this modification to two examples: a transcendental equation and a cubic equation of state. The results demonstrate that the proposed modifications guarantee at least interval halving and offer a slight improvement in the efficiency of the root-finding process. © 2024 The Author(s)

关键词： Brent method Dekker method Hybrid method Interval halving Root finding

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A sharp interface Lagrangian-Eulerian method for flexible-body fluid-structure interaction

arXiv

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arXiv 2022年

作者： Kolahdouz, Ebrahim M. Wells, David R. Rossi, Simone Aycock, Kenneth I. Craven, Brent A. Griffith, Boyce E. Center for Computational Biology Flatiron Institute Simons Foundation New YorkNY United States Department of Mathematics University of North Carolina Chapel HillNC United States Division of Applied Mechanics Office of Science and Engineering Laboratories Center for Devices and Radiological Health United States Food and Drug Administration Silver SpringMD United States Departments of Mathematics and Biomedical Engineering University of North Carolina Chapel HillNC United States Carolina Center for Interdisciplinary Applied Mathematics University of North Carolina Chapel HillNC United States Computational Medicine Program University of North Carolina Chapel HillNC United States McAllister Heart Institute University of North Carolina Chapel HillNC United States

This paper introduces a sharp-interface approach to simulating fluid-structure interaction (FSI) involving flexible bodies described by general nonlinear material models and across a broad range of mass density ratios. This new flexible-body immersed Lagrangian-Eulerian (ILE) scheme extends our prior work on integrating partitioned and immersed approaches to rigid-body FSI. Our numerical approach incorporates the geometrical and domain solution flexibility of the immersed boundary (IB) method with an accuracy comparable to body-fitted approaches that sharply resolve flows and stresses up to the fluid-structure interface. Unlike many IB methods, our ILE formulation uses distinct momentum equations for the fluid and solid subregions with a Dirichlet-Neumann coupling strategy that connects fluid and solid subproblems through simple interface conditions. As in earlier work, we use approximate Lagrange multiplier forces to treat the kinematic interface conditions along the fluid-structure interface. This penalty approach simplifies the linear solvers needed by our formulation by introducing two representations of the fluid-structure interface, one that moves with the fluid and another that moves with the structure, that are connected by stiff springs. This approach also enables the use of multi-rate time stepping, which allows us to use different time step sizes for the fluid and structure subproblems. Our fluid solver relies on an immersed interface method (IIM) for discrete surfaces to impose stress jump conditions along complex interfaces while enabling the use of fast structured-grid solvers for the incompressible Navier-Stokes equations. The dynamics of the volumetric structural mesh are determined using a standard finite element approach to large-deformation nonlinear elasticity via a nearly incompressible solid mechanics formulation. This formulation also readily accommodates compressible structures with a constant total volume, and it can handle fully compressibl

关键词： Fluid structure interaction

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Ferroelectric transistors based on shear-transformation-mediated rhombohedral-stacked molybdenum disulfide

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Nature Electronics 2024年第1期7卷 29-38页

作者： Yang, Tilo H. Liang, Bor-Wei Hu, Hsiang-Chi Chen, Fu-Xiang Ho, Sheng-Zhu Chang, Wen-Hao Yang, Liu Lo, Han-Chieh Kuo, Tzu-Hao Chen, Jyun-Hong Lin, Po-Yen Simbulan, Kristan Bryan Luo, Zhao-Feng Chang, Alice Chinghsuan Kuo, Yi-Hao Ku, Yu-Seng Chen, Yi-Cheng Huang, You-Jia Chang, Yu-Chen Chiang, Yu-Fan Lu, Ting-Hua Lee, Min-Hung Li, Kai-Shin Wu, Menghao Chen, Yi-Chun Lin, Chun-Liang Lan, Yann-Wen Department of Physics National Taiwan Normal University Taipei Taiwan Taiwan Semiconductor Research Institute National Applied Research Laboratories Hsinchu Taiwan Department of Electrophysics National Yang Ming Chiao Tung University Hsinchu Taiwan Department of Physics National Cheng Kung University Tainan Taiwan School of Physics Huazhong University of Science and Technology Wuhan China Institute of Cellular and Organismic Biology Academia Sinica Taipei Taiwan Department of Mathematics and Physics University of Santo Tomas Manila Philippines Program for Semiconductor Devices Materials and Hetero-integration Graduate School of Advanced Technology National Taiwan University Taipei Taiwan Hsinchu Taiwan Department of Physics National Taiwan University Taipei Taiwan Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology CambridgeMA United States

To develop low-power, non-volatile computing-in-memory device using ferroelectric transistor technologies, ferroelectric channel materials with scaled thicknesses are required. Two-dimensional semiconductors, such as molybdenum disulfide (MoS2), equipped with sliding ferroelectricity could provide an answer. However, achieving switchable electric polarization in epitaxial MoS2 remains challenging due to the absence of mobile domain boundaries. Here we show that polarity-switchable epitaxial rhombohedral-stacked (3R) MoS2 can be used as a ferroelectric channel in ferroelectric memory transistors. We show that a shear transformation can spontaneously occur in 3R MoS2 epilayers, producing heterostructures with stable ferroelectric domains embedded in a highly dislocated and unstable non-ferroelectric matrix. This diffusionless phase transformation process produces mobile screw dislocations that enable collective polarity control of 3R MoS2 via an electric field. Polarization–electric-field measurements reveal a switching field of 0.036 V nm−1 for shear-transformed 3R MoS2. Our sliding ferroelectric transistors are non-volatile memory units with thicknesses of only two atomic layers and exhibit an average memory window of 7 V with an applied voltage of 10 V, retention times greater than 104 seconds and endurance greater than 104 cycles. © 2023, The Author(s), under exclusive licence to Springer Nature Limited.

关键词： Molybdenum disulfide

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