Nanoscale Chemical Imaging of Nanoparticles under Real-World Wastewater Treatment Conditions
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99 GENERAL AND MISCELLANEOUS↗
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Grain Boundary Segregation Suppresses Local Short‐Range Ordering in Nanocrystalline High‐Entropy Alloys
Multi-principal-element alloys like high-entropy alloys (HEAs) have potential applications in many engineering fields due to their unique mechanical/functional properties. While HEAs are generally considered random solid solutions, recent studies revealed that they are prone to short-range-ordering (SRO) due to the complex multi-pair-wise interactions among the constituent elements. Meanwhile, SROs' evolution can sometimes be deleterious, and it is necessary to have control over their evolution. Examining the AlCoCrFe-Zr model alloy, long-range ordering occurs following the expectation of enthalpic predictions. Advanced characterization techniques—transmission electron microscopy, high-energy synchrotron X-ray diffraction/pair distribution function, and atom probe tomography, reveal that SRO is suppressed in as-milled and GB-decorated NC-(AlCoCrFe)100-xZrx (x = 0–1.5 atomic %). Warren-Cowley coefficient calculations are further used to validate the suppression of SRO. Besides the low segregation enthalpies of Cr, Fe, and Zr, and the high-mixing enthalpy of Cr and Fe, the short diffusion path to GBs due to high-GB density in the NC-HEAs and the higher energy state of the GBs than the matrix promotes GB-segregation that further alters the matrix chemistry and consequently disfavors SRO formation within the matrix. Despite the GB-segregation of Cr, Fe, and Zr, the matrices and GBs remain in a random solid solution.
36 MATERIALS SCIENCE↗
Fully R2R-Printed Carbon-Nanotube-Based Limitless Length of Flexible Active-Matrix for Electrophoretic Display Application
A limitless-length flexible active-matrix implies that virtually any surface can be rendered into an interactive medium when laminated with electrophoretic or organic light-emitting diode sheets. However, performance, cost, and size limitations of current fabrication technologies and semiconducting materials, typically utilized in thin film transistor (TFT) active matrices (TFT-AMs), have hindered progress, thus preventing the realization of fully printed TFT-AMs on a plastic roll. Here, a new high-purity semiconducting single-walled carbon nanotube (s-SWCNT) ink is prepared by first isolating 99.9% pure s-SWCNTs via conjugated polymer extraction, and then utilizing a ligand-exchange method to formulate a novel hydrophilic gravure-compatible semiconducting ink. Based on the s-SWCNT ink, a fully additive manufacturing process using roll-to-roll (R2R) gravure printing enables the fabrication of a flexible TFT-AM, overcoming performance, cost, and size limitations. TFT-AMs with 10 to 40 PPI resolution where average mobility of 0.23 ± 0.12 cm 2 V –1 s –1 , average on–off ratio of 10 4.1 , and threshold voltage variation of ±13% are attained. As a proof of concept, an inexpensive and flexible electrophoretic display is demonstrated by simply laminating an electrophoretic sheet onto the R2R gravure-printed s-SWCNT-based TFT-AM.
36 MATERIALS SCIENCE↗
Tailoring Molecular Space to Navigate Phase Complexity in Cs-Based Quasi-2D Perovskites via Gated-Gaussian-Driven High-Throughput Discovery
Cesium-based quasi-2D halide perovskites (HPs) offer promising functionalities and low-temperature manufacturability, suited to stable tandem photovoltaics. However, the chemical interplays between the molecular spacers and the inorganic building blocks during crystallization cause substantial phase complexities in the resulting matrices. To successfully optimize and implement the quasi-2D HP functionalities, a systematic understanding of spacer chemistry, along with the seamless navigation of the inherently discrete molecular space, is necessary. Herein, by utilizing high-throughput automated experimentation, the phase complexities in the molecular space of quasi-2D HPs are explored, thus identifying the chemical roles of the spacer cations on the synthesis and functionalities of the complex materials. Furthermore, a novel active machine learning algorithm leveraging a two-stage decision-making process, called gated Gaussian process Bayesian optimization is introduced, to navigate the discrete ternary chemical space defined with two distinctive spacer molecules. Through simultaneous optimization of photoluminescence intensity and stability that “tailors” the chemistry in the molecular space, a ternary-compositional quasi-2D HP film realizing excellent optoelectronic functionalities is demonstrated. Finally, this work not only provides a pathway for the rational and bespoke design of complex HP materials but also sets the stage for accelerated materials discovery in other multifunctional systems.
36 MATERIALS SCIENCE↗
Quantum‐Classical Simulation of Quantum Field Theory by Quantum Circuit Learning
Abstract Quantum circuit learning is employed to simulate quantum field theories (QFTs). Typically, when simulating QFTs with quantum computers, significant challenges are encountered due to the technical limitations of quantum devices when implementing the Hamiltonian using Pauli spin matrices. To address this challenge, quantum circuit learning is leveraged, employing a compact configuration of qubits and low‐depth quantum circuits to predict real‐time dynamics in quantum field theories. The key advantage of this approach is that a single‐qubit measurement can accurately forecast various physical parameters, including fully‐connected operators. To demonstrate the effectiveness of this method, it is used to predict quench dynamics, chiral dynamics and jet production in a 1+1‐dimensional model of quantum electrodynamics. It is found that our predictions closely align with the results of rigorous classical calculations, exhibiting a high degree of accuracy. This hybrid quantum‐classical approach illustrates the feasibility of efficiently simulating large‐scale QFTs on cutting‐edge quantum devices.
Ikeda, Kazuki [Department of Physics University of↗
Carbon fiber/epoxy vitrimer composite patch cured with bio‐based curing agents for one‐step repair metallic sheet and its recyclability
Abstract Vitrimers have gained a great deal of attention from researchers, yet research on its application is still lacking. This study, a novel bio‐based vitrimer was developed from epoxy (EP) and bio‐based curing agents, that is, cashew nut shell liquid (CNSL) and citric acid (CA), and then reinforced by carbon fiber. The vitrimers with different ratios of acid to epoxy (R ratio) at 0.30–0.40 contained ester and ether linkages. All EP/CA/CNSL vitrimers showed the stress relaxation over 70–100°C due to transesterification. The vitrimers were applied as polymer matrices for the carbon fiber composites and then used as repair patches. By using the carbon fiber‐reinforced vitrimer with the R ratio of 0.30, patch repair on a damaged alloy sheet revealed that approximately 98% of the tensile strength of the damaged alloy sheet was recovered. The vitrimer can be dissolved from carbon fiber composite to recover carbon fiber. The recovered carbon fiber retained good tensile strength compared to the pristine composite. Based on this study, the EP/CA/CNSL vitrimers showed the comparable thermomechanical properties with the epoxy vitrimer cured by the petroleum‐based curing agent. The vitrimer composite patch could therefore be an alternative new repair method to extend the service life of damaged structures.
Lorwanishpaisarn, Narubeth↗
Behavioral and neuroinflammatory changes caused by glyphosate: Base herbicide in mice offspring
Abstract Background Glyphosate is a pesticide considered of low toxicity, but scientific evidences show it can be harmful to health. This study aimed to evaluate the toxicity in mice offspring exposed to glyphosate‐based herbicide (GBH) during the intrauterine period. Methods Female matrices received glyphosate 0.3 mg/kg daily per oral throughout the gestational period, which was variable between 18 and 22 days. From the 25th until the 28th days post‐birth, mice offspring were subjected to behavioral tests, and the prefrontal cortex was processed for immunohistochemical analysis. Results Two significant behavioral changes were observed: anxiety in the GLIF0.3 group, increase in the behavior burying marbles in the marble‐burying test and hyperactivity, expressed by the significant increase of the crossing number in the open field test. The increased microglia, TNF‐alpha, and astrocyte expression were also observed in the prefrontal cortex of offspring treated with GLIF0.3. Conclusion Exposure to GBH during mice intrauterine development induces hyperactive and anxious behavior, evidencing neuroinflammation.
de Castro Vieira Carneiro, Carla Larissa↗
Likelihood Maximization and Moment Matching in Low SNR Gaussian Mixture Models
We derive an asymptotic expansion for the log-likelihood of Gaussian mixture models (GMMs) with equal covariance matrices in the low signal-to-noise regime. The expansion reveals an intimate connection between two types of algorithms for parameter estimation: the method of moments and likelihood optimizing algorithms such as Expectation-Maximization (EM). We show that likelihood optimization in the low SNR regime reduces to a sequence of least squares optimization problems that match the moments of the estimate to the ground truth moments one by one. This connection is a stepping stone towards the analysis of EM and maximum likelihood estimation in a wide range of models. A motivating application for the study of low SNR mixture models is cryo-electron microscopy data, which can be modeled as a GMM with algebraic constraints imposed on the mixture centers. We discuss the application of our expansion to algebraically constrained GMMs, among other example models of interest. © 2022 The Authors. Communications on Pure and Applied Mathematics published by Wiley Periodicals LLC.
97 MATHEMATICS AND COMPUTING↗
Nucleophilic Thiols Reductively Cleave Ether Linkages in Lignin Model Polymers and Lignin
Lignin may serve as a renewable feedstock for the production of chemicals and fuels if mild, scalable processes for its depolymerization can be devised. The use of small organic thiols represents a bioinspired strategy to cleave the β–O–4 bond, the most common linkage in lignin. In the present study, synthetic β–O–4 linked polymers were treated with organic thiols, yielding up to 90 % cleaved monomer products. Lignin extracted from poplar was also treated with organic thiols resulting in molecular weight reductions as high as 65 % (Mn) in oxidized lignin. Thiol–based cleavage of other lignin linkages was also explored in small–molecule model systems to uncover additional potential pathways by which thiols might depolymerize lignin. The success of thiol–mediated cleavage on model dimers, polymers, and biomass–derived lignin illustrates the potential utility of small redox–active molecules to penetrate complex polymer matrices for depolymerization and subsequent valorization of lignin into fuels and chemicals.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
The evaluation of aluminum and iron metal oxide settling behaviors for Hanford insoluble solids waste preprocessing
The Hanford site is currently one of the largest and most expensive cleanup sites for hazardous, radioactive waste. Over 20% of the waste found at the Hanford site is in the form of a high activity sludge. The insoluble solids in the sludge will need to be concentrated prior to vitrification in the high-level waste (HLW) melter. This will minimize the amount of liquid that will be evaporated during the melting process and expedite the melter processing rate. One proposed option for concentrating the insoluble solids is gravity settling in the storage tanks. Metal oxide compounds containing aluminum and iron make up the majority of the insoluble solids in the sludge, therefore understanding the behavior of these compounds in various tank waste matrices can facilitate sludge pretreatment options. A study of non-radioactive slurry solutions containing Al(OH) 3 (gibbsite), AlO(OH) (boehmite), and Fe 2 O 3 (iron (III) oxide) was conducted to determine the time dependent interface behavior and settling rates of these compounds. Variations in solids loading and sodium concentration were evaluated to represent waste processing conditions and the results of these settling studies were compared with prior tank waste settling tests. Information gathered from these studies can be used to inform future decisions on sludge treatment processes of the insoluble solids processed at the Hanford site.
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Enhanced prediction of Cs removal by CST from Hanford tank waste with K accountability
Abstract The treatment of Hanford tank waste is one of the most challenging environmental cleanup activities to date. To expedite the processing of liquid waste stored in underground tanks in Washington State it is necessary to remove the significant dose contributor, 137 Cs. Crystalline silicotitanate ion exchanger is currently used to remove 137 Cs from the aqueous phase of Hanford tank wastes in preparation for vitrification at the Waste Treatment and Immobilization Plant (WTP). Improving the understanding of potassium impacts on ion exchange behavior of Cs will help in the operation of a critical component of one of the most complex treatment processes in the world today. Optimization of this process can result in significant cost savings and less waste production. Toward this effort, a series of batch contact tests varied in potassium concentration were conducted to look at the impact of potassium concentration on Cs distribution. Experimental distribution ratios ( K d ) were compared to the distribution ratios predicted using the ZAM model. A significant underprediction of Cs capacity in the presence of potassium was seen with the existing model. A revision of the equilibrium constants was determined and provided a statistically better fit for determining the Cs K d values in tank waste matrices.
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Toward Validation of Toxicological Interpretation of Diffusive Gradients in Thin Films in Marine Waters Impacted by Copper
Determination of Mytilus galloprovincialis larvae median effect concentration (EC50), of Cu in coastal marine waters by diffusive gradient in thin-films (DGT), has been shown to effectively reduce the need to consider dissolved organic carbon (DOC) concentration and quality. West coast marine and estuarine organisms’ chronic toxicity test protocol was used to validate previously modelled protective effects, afforded to highly sensitive marine larvae by ligand competition, in five diverse site waters. The results demonstrate significant narrowing of toxicological endpoints, where EC50s ranged from 3.74 – 6.67 µg/L as CDGT Cu versus 8.76 – 26.8 µg/L as CuDISS over a DOC range of 0.74 – 3.11 mg/L. Additionally, DOC quality (characterized by fluorescence excitation and emission matrices) indicates that the heterogeneity of competing Cu binding ligands, in common marine waters, minimizes the need for class determinations toward explaining the degree of protection, when assumptions in criterion maximum concentration (CMC) setting are conservative. A CDGT Cu EC50 of 3.7 µg/L, and corresponding CMC CDGT Cu of 1.8 µg/L, for universal application by regulatory compliance-monitoring programs, are proposed as a superior approach toward both integration of dynamic water quality over effective exposure periods and quantification of biologically-relevant trace Cu speciation and are demonstrated by in situ data.
Diffusive Gradients in Thin-films, copper, seawate↗
Identifying the mechanisms of cation inhibition of phenol oxidation by acid birnessite
Abstract Many phenolic compounds found as contaminants in natural waters are susceptible to oxidation by manganese oxides. However, there is often variability between oxidation rates reported in pristine matrices and studies using more environmentally relevant conditions. For example, the presence of cations generally results in slower phenolic oxidation rates. However, the underlying mechanism of cation interference is not well understood. In this study, cation co‐solutes inhibit the transformation of four target phenols (bisphenol A, estrone, p ‐cresol, and triclosan) by acid birnessite. Oxidation rates for these compounds by acid birnessite follow the same trend (Na + > K + > Mg 2+ > Ca 2+ ) when cations are present as co‐solutes. We further demonstrate that the same trend applies to these cations when they are absent from solution but pre‐exchanged with the mineral. We analyze valence state, surface area, crystallinity, and zeta potential to characterize changes in oxide structure. The findings of this study show that pre‐exchanged cations have a large effect on birnessite reactivity even in the absence of cation co‐solutes, indicating that the inhibition of phenolic compound oxidation is not due to competition for surface sites, as previously suggested. Instead, the reaction inhibition is attributed to changes in aggregation and the mineral microstructure.
Balgooyen, Sarah↗
Investigating the impacts of solid phase extraction on dissolved organic matter optical signatures and the pairing with high‐resolution mass spectrometry data across a freshwater stream network
Abstract Advancing our understanding of dissolved organic matter (DOM) chemistry in aquatic systems necessitates the integration of data streams from multiple analytical platforms. Some measurements require pretreatment with solid phase extraction (SPE), while others are performed directly on whole water samples. Evidence has suggested that SPE will be biased against select DOM fractions, leading to concerns over the ability to establish data linkages across platforms with variable needs for SPE pretreatment, such as those from optical measurements and those that provide high‐resolution molecular information. Here, we directly addressed this concern by assessing the impact of SPE on DOM optical properties through excitation–emission matrices with parallel factor analysis (PARAFAC) for 47 samples across a stream network within a single watershed reflective of variable DOM sources. PARAFAC data was further paired with molecular information obtained by Fourier transform ion cyclotron resonance mass spectrometry (FTICR‐MS). A comparison of PARAFAC models first revealed no systematic qualitative differences in major components between whole water DOM and DOM isolated by SPE (SPE‐DOM); however, quantitative biases against select components were observed. Further linkages with FTICR‐MS data revealed that the molecular fingerprint associated with each PARAFAC component was consistent between the whole water DOM and SPE‐DOM. Our results suggest that bulk scale linkages across these analytical platforms could be inferred irrespective of the observed quantitative biases resulting from SPE for samples within this example watershed. This work represents a key step toward the systematic evaluation of linkages between optical and high‐resolution mass spectrometry datasets in freshwater lotic environments.
59 BASIC BIOLOGICAL SCIENCES↗
An extended numerical manifold method for unsaturated soil-water interaction analysis at micro-scale
To investigate unsaturated soil-water interaction at micro-scale, this work extends the numerical manifold method (NMM) by incorporating a soil-water coupling model considering specific capillary water distribution and capillary force calculation. The soil skeleton is constructed by a soil skeleton generation algorithm with random polygons. To more realistically capture the interaction between soil grains and capillary water, a capillary mechanics-based geometric algorithm is proposed to iteratively calculate the capillary water distribution. The capillary forces corresponding to the capillary water distribution are calculated based on the Young-Laplace equation. The proposed capillary water solving framework is first verified by reproducing the soil-water characteristic curve and the capillary water distribution of an ideal contact-disk model against analytical solutions. To further validate the ability of the capillary water solving framework to predict hydraulic behavior of the real soil, a laboratory test on the Toyoura sand is reproduced numerically. Then an ideal direct shear test is performed to further validate the two-way soil-water coupling procedure, in which a comparison between the numerical and analytical results regarding the shear strength and matric suction is presented. Finally, microscopic hydraulic and compression tests are conducted on two soil specimens with the same porosity and mean grain diameter but different uniformity coefficients. The results elucidate that the extended method is a potential tool to explore unsaturated soil behaviors at micro-scale.
58 GEOSCIENCES↗
The tensor t‐function: A definition for functions of third‐order tensors
Summary A definition for functions of multidimensional arrays is presented. The definition is valid for third‐order tensors in the tensor t‐product formalism, which regards third‐order tensors as block circulant matrices. The tensor function definition is shown to have similar properties as standard matrix function definitions in fundamental scenarios. To demonstrate the definition's potential in applications, the notion of network communicability is generalized to third‐order tensors and computed for a small‐scale example via block Krylov subspace methods for matrix functions. A complexity analysis for these methods in the context of tensors is also provided.
Lund, Kathryn↗
Quantum Fourier transform revisited
Summary The fast Fourier transform (FFT) is one of the most successful numerical algorithms of the 20th century and has found numerous applications in many branches of computational science and engineering. The FFT algorithm can be derived from a particular matrix decomposition of the discrete Fourier transform (DFT) matrix. In this paper, we show that the quantum Fourier transform (QFT) can be derived by further decomposing the diagonal factors of the FFT matrix decomposition into products of matrices with Kronecker product structure. We analyze the implication of this Kronecker product structure on the discrete Fourier transform of rank‐1 tensors on a classical computer. We also explain why such a structure can take advantage of an important quantum computer feature that enables the QFT algorithm to attain an exponential speedup on a quantum computer over the FFT algorithm on a classical computer. Further, the connection between the matrix decomposition of the DFT matrix and a quantum circuit is made. We also discuss a natural extension of a radix‐2 QFT decomposition to a radix‐ d QFT decomposition. No prior knowledge of quantum computing is required to understand what is presented in this paper. Yet, we believe this paper may help readers to gain some rudimentary understanding of the nature of quantum computing from a matrix computation point of view.
Camps, Daan↗
Matrix-free preconditioning for high-order H (curl) discretizations
The greater arithmetic intensity of high-order finite element discretizations makes them attractive for implementation on next-generation hardware, but assembly of high-order finite element operators as matrices is prohibitively expensive. As a result, the development of general algebraic solvers for such operators has been an open research challenge. Fast matrix-free application of high-order operators has received significant attention in the literature in the context of Poisson-type problems, but preconditioners and solvers for inverting more general operators are not very well-developed. In this paper, we consider the problem of preconditioning a definite Maxwell operator at high polynomial order without assembling a matrix. We show that given efficient preconditioners for high-order H 1 finite element problems on the same mesh, efficient H(curl) preconditioners can be constructed in an auxiliary space framework. We demonstrate the resulting preconditioners in a practical setting with tensor-product basis functions on an unstructured mesh of quadrilaterals. Overall, our approach uses a sparsified H 1 solver constructed on a low-order mesh of the nodal points of the underlying high-order space, and we show that the resulting H(curl) preconditioner is effective at very high polynomial orders for two-dimensional model problems with complicated geometry, varying piecewise constant coefficients, and curved elements. The resulting preconditioner scales with nearly optimal O(p d+1 ) floating point operation count and optimal O(p d ) memory transfer requirements, outperforming existing Maxwell preconditioners in the high-order regime.
97 MATHEMATICS AND COMPUTING↗