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1. Defining the challenges of Li extraction with olivine host: The roles of competitor and spectator ions

   https://doi.org/10.1073/pnas.2200751119  

   Yan, Gangbin; Wang, Mingzhan; Hill, Grant T.; Zou, Siqi; Liu, Chong (August 2022, Proceedings of the National Academy of Sciences)

   The lithium supply issue mainly lies in the inability of current mining methods to access lithium sources of dilute concentrations and complex chemistry. Electrochemical intercalation has emerged as a highly selective method for lithium extraction; however, limited source compositions have been studied, which is insufficient to predict its applicability to the wide range of unconventional water sources (UWS). This work addresses the feasibility and identifies the challenges of Li extraction by electrochemical intercalation from UWS, by answering three questions: 1) Is there enough Li in UWS? 2) How would the solution compositions affect the competition of Li + to major ions (Na + /Mg 2+ /K + /Ca 2+ )? 3) Does the complex solution composition affect the electrode stability? Using one-dimensional olivine FePO 4 as the model electrode, we show the complicated roles of major ions. Na + acts as the competitor ion for host storage sites. The competition from Na + grants Mg 2+ and Ca 2+ being only the spectator ions. However, Mg 2+ and Ca 2+ can significantly affect the charge transfer of Li + and Na + , therefore affecting the Li selectivity. We point to improving the selectivity of Li + to Na + as the key challenge for broadening the minable UWS using the olivine host. 

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2. What do we hear from a drum? A data-consistent approach to quantifying irreducible uncertainty on model inputs by extracting information from correlated model output data

   https://doi.org/https://doi.org/10.1016/j.cma.2020.113228  

   Butler, T.; Hakula, H. (October 2020, Computer methods in applied mechanics and engineering)

   null (Ed.)

   In manufacturing processes, controlling system responses with uncertain system inputs, e.g., due to variations in material parameters of critical system sub-components, is a crucial task for performing reliable quality control and verification & validation (V&V) of system design. As a model for a manufacturing process, we consider the production of drums, that is, thin elastic membranes, whose properties are modeled via Dirichlet Laplacian eigenproblems with uncertain diffusion coefficients. Both a quality control and V&V problem are formulated within a data-consistent framework utilizing push-forward and pullback measures. In both problems, the uncertain diffusion coefficients are parameterized for every instance and the corresponding eigen-information defines correlated data streams. Subsequently, the quantities of interest required in the solution to the data-consistent inverse problems are determined by an a posteriori analysis of these data streams using feature extraction techniques. While the methodology proposed here is quite general, the specific efficacy of the proposed methodology is comprehensively explored in the numerical results for both the quality control and V&V problems associated with the manufacturing of drums. 

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3. A comparative study of porous and hollow carbon nanofibrous structures from electrospinning for supercapacitor electrode material development

   https://doi.org/10.1016/j.surfin.2021.101386  

   K Asare, MF Hasan (August 2021, Surfaces and interfaces)

   Co-axial electrospinning is an efficient technique to develop core-shell or hollow nanofibrous structures. In this study electrospun carbon nanofibers with three different morphologies, i.e. solid nanofibers with porous structure (P-ECNF), hollow nanofibers with solid wall (H-ECNF), and hollow nanofibers with porous wall (HP-ECNF) were developed through bicomponent electrospinning and co-axial electrospinning of polyacrylonitrile (PAN) and poly (methyl methacrylate) (PMMA) by varying proportion of the sacrificial PMMA. Through comparative electrochemical analyses, it is revealed that the primary factors for electrochemical performance, i.e. specific capacitance, of the electrospun carbon nanofibrous materials are mesopore volume and total pore volume. The hollow structure as well as ordered carbon structure and intact fiber structure also benefits electrolyte transfer and subsequent electrochemical performance but is secondary. Overall the porous carbon nanofibrous electrode material from electrospinning PAN/PMMA (50/50) solution (P-ECNF-50-50) outperformed those hollow and hollow-porous counterparts from co-axial electrospinning and demonstrated the largest specific capacitance due to the largest mesopore volume as well as the largest total pore volume. This electrode material also showed excellent cycling stability (without any loss of specific capacitance) after 3,000 cycles of charging and discharging. It even showed some increase of specific capacitance with cycling test due to its relatively large amount of micropores. 

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4. Non-Destructive Estimation of Spatially Varying Thermal Conductivity in 3D Objects Using Boundary Thermal Measurements

   Reddy, Sohail R; Dulikravich, George S; Zeidi, Javad SM (April 2017, International journal of thermal sciences)

   A methodology for non-destructive, accelerated inverse estimation of spatially varying material properties using only boundary measurements is presented. The spatial distribution of diffusion coefficient in 3D solid object is determined by minimizing the sum of the least-squares difference between measured and calculated values. The forward problem is solved using the finite volume and finite element methods, both of which were compared against analytical solution. The inverse problem was solved using an optimization technique to minimize the sum of the least-square errors. The non-destructive estimation was accelerated by the use of surrogate models to solve the forward problem. The presented methodology is applied to measurements containing varying levels of noise. Finally, it is used to detect both the location, size and shape of a subdomain within a solid object and material property of the subdomain material. 

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5. The Direct Arylation Polymerization (DArP) of Well‐Defined Alternating Copolymers Based On 5,6‐Dicyano[2,1,3]benzothiadiazole (DCBT)

   https://doi.org/10.1002/ajoc.201800232  

   Shi, Qinqin; Tatum, Wesley; Zhang, Junxiang; Scott, Colleen; Luscombe, Christine_K; Marder, Seth_R; Blakey, Simon_B (June 2018, Asian Journal of Organic Chemistry)

   Abstract Alternating donor–acceptor copolymers are important materials with readily tunable optical and electronic properties. Direct arylation polymerization (DArP) is emerging as an attractive synthetic methodology for the synthesis of these polymers, avoiding the use of prefunctionalized building blocks. However, challenges remain in achieving well‐defined structure, high molecular weight, and impurity‐free polymers. Herein, a study to synthesize three well‐defined donor–acceptor copolymers through DArP is presented. Comparison of¹H NMR and¹³C NMR, as well as optical and electrochemical properties analysis for the polymers and corresponding oligomers provides evidence for the regioregular structure of the polymers. On the basis of the chemical structure of poly(IIDCBT) and the solution electrochemical studies we surmised poly(IIDCBT) could potentially be an electron transport material for organic field‐effect transistors (OFETs), and we determined an electron mobility of 1.2×10⁻³ cm² V⁻¹ s⁻¹for this material. 

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