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Abstract Potassium sodium niobate, i.e., K_0.5Na_0.5NbO₃or KNN, is an important lead (Pb)-free, perovskite-structured, piezoelectric ceramic composition. KNN is typically synthesized by solid-state reaction of the unary alkali carbonates, i.e., K₂CO₃and Na₂CO₃, with Nb₂O₅at high temperatures. It is well known that this reaction can result in chemically inhomogeneous powders and ceramics, which can have deleterious effects on key physical properties. In this work, we demonstrate that substantial improvements in chemical homogeneity of KNN are achieved by initially pre-reacting the unary carbonates to form the binary carbonate KNaCO₃, and then subsequently reacting KNaCO₃with Nb₂O₅to form KNN. The binary carbonate, KNaCO₃, is a distinct compound with a unique structure relative to the unary carbonates. In contrast with the unary carbonates, the consumption of KNaCO₃during the reaction to form KNN facilitates the balanced incorporation of K⁺and Na⁺into the growing KNN phase, leading to improved chemical homogeneity. Key methods include in situ X-ray diffraction (XRD) during thermal treatment, scaled-up batch processing in a muffle furnace, and Williamson–Hall analysis of XRD patterns to determine changes in microstrain due to chemical homogeneity. 

Abstract Potassium carbonate (K₂CO₃) and sodium carbonate (Na₂CO₃) are useful inorganic alkali salts with a multitude of uses, although both can be unstable at room temperature. The focus of this work was to react these two unary carbonates together to form KNaCO₃single crystals, and to determine the structure of the resulting crystals. The symmetry of the crystals was assigned to the monoclinic space groupC2/c(No. 15), with lattice parameters (Ǻ) of 5.4546(7), 9.462(1), 6.1282(7), andβ = 95.209(4). The K and Na are located on fully occupied, symmetry-unique atomic positions. The phase evolution of K₂CO₃and Na₂CO₃to form KNaCO₃was also examined using in situ high temperature X-ray diffraction. The final compound in both single crystal and powder form was found to be stable over time at room temperature. 

Background: DJ-1 is a protein whose mutation causes rare heritable forms of Parkinson’s disease (PD) and is of interest as a target for treating PD and other disorders. This work used high performance affinity microcolumns to screen and examine the binding of small molecules to DJ-1, as could be used to develop new therapeutics or to study the role of DJ-1 in PD. Non-covalent entrapment was used to place microgram quantities of DJ-1 in an unmodified form within microcolumns, which were then used in multiple studies to analyze binding by model compounds and possible drug candidates to DJ-1. Results: Several factors were examined in optimizing the entrapment method, including the addition of a reducing agent to maintain a reduced active site cysteine residue in DJ-1, the concentration of DJ-1 employed, and the entrapment times. Isatin was used as a known binding agent (dissociation constant, ~2.0 µM) and probe for DJ-1 activity. This compound gave good retention on 2.0 cm × 2.1 mm inner diameter DJ-1 microcolumns made under the final entrapment conditions, with a typical retention factor of 14 and elution in ~8 min at 0.50 mL/min. These DJ-1 microcolumns were used to evaluate the binding of small molecules that were selected in silico to bind or not to bind DJ-1. A compound predicted to have good binding with DJ-1 gave a retention factor of 122, an elution time of ~15 min at 0.50 mL/min, and an estimated dissociation constant for this protein of 0.5 µM. Significance: These chromatographic tools can be used in future work to screen additional possible binding agents for DJ-1 or adapted for examining drug candidates for other proteins. This work represents the first time protein entrapment has been deployed with DJ-1, and it is the first experimental confirmation of binding to DJ-1 by a small lead compound selected in silico. 

The solid-state synthesis of perovskite BiFeO3 has been a topic of interest for decades. Many studies have reported challenges in the synthesis of BiFeO3 from starting oxides of Bi2O3 and Fe2O3, mainly associated with the development of persistent secondary phases such as Bi25FeO39 (sillenite) and Bi2Fe4O9 (mullite). These secondary phases are thought to be a consequence of unreacted Fe-rich and Bi-rich regions, that is, incomplete interdiffusion. In the present work, in situ high-temperature X-ray diffraction is used to demonstrate that Bi2O3 first reacts with Fe2O3 to form sillenite Bi25FeO39, which then reacts with the remaining Fe2O3 to form BiFeO3. Therefore, the synthesis of perovskite BiFeO3 is shown to occur via a two-step reaction sequence with Bi25FeO39 as an intermediate compound. Because Bi25FeO39 and the γ-Bi2O3 phase are isostructural, it is difficult to discriminate them solely from X-ray diffraction. Evidence is presented for the existence of the intermediate sillenite Bi25FeO39 using quenching experiments, comparisons between Bi2O3 behavior by itself and in the presence of Fe2O3, and crystal structure examination. With this new information, a proposed reaction pathway from the starting oxides to the product is presented. 

Today’s challenges with sustainability are driven by complexity, lack necessary information, resist straightforward solutions, span multiple scales, and encompass diverse or sometimes conflicting perspectives. To tackle these issues effectively, research organizations need tools that support and accelerate the integration of disciplinary knowledge across both natural and social sciences so that they can explore and execute workable solutions. Boundary objects are tools that can bring diverse perspectives together through a shared point of focus that is meaningful across different groups and perspectives, enhancing communication between them. Here, we introduce a framework to develop Triple Bottom Line Scenario Sites (TBL Sites) as “convergence” boundary objects and intervention testbeds to support a holistic approach to sustainability research within multidisciplinary and multi-institutional organizations. We describe four key criteria used to identify a potential TBL Site: (1) proximity to researchers, (2) a bounded geographic location encompassing a particular ecosystem, (3) an integrated stakeholder network, and (4) access to existing resources. We explain how TBL Sites may be used to assess research impacts on environmental, economic, and social sustainability goals. Finally, we provide examples of aquatic, agricultural, and urban TBL Sites used by the Science and Technologies for Phosphorus Sustainability (STEPS) Center, demonstrating how these boundary objects facilitate convergence across a large multidisciplinary research team to tackle sustainable phosphorus management.