The increasing severity of pathogenic and environmental stressors that negatively affect plant health has led to interest in developing next-generation agrochemical delivery systems capable of precisely transporting active agents to specific sites within plants. In this work, we adapt Flash NanoPrecipitation (FNP), a scalable nanocarrier (NC) formulation technology used in the pharmaceutical industry, to prepare organic core-shell NCs and study their efficacy as foliar or root delivery vehicles. NCs ranging in diameter from 55 to 200 nm, with surface zeta potentials from -40 to +40 mV, and with seven different shell material properties were prepared and studied.
View Article and Find Full Text PDFThe Oak Ridge National Laboratory is planning to build the Second Target Station (STS) at the Spallation Neutron Source (SNS). STS will host a suite of novel instruments that complement the First Target Station's beamline capabilities by offering an increased flux for cold neutrons and a broader wavelength bandwidth. A novel neutron imaging beamline, named the Complex, Unique, and Powerful Imaging Instrument for Dynamics (CUPI2D), is among the first eight instruments that will be commissioned at STS as part of the construction project.
View Article and Find Full Text PDFCopper (Cu) and iron (Fe) are essential micronutrients that are toxic when accumulating in excess in cells. Thus, their uptake by roots is tightly regulated. While plants sense and respond to local Cu availability, the systemic regulation of Cu uptake has not been documented in contrast to local and systemic control of Fe uptake.
View Article and Find Full Text PDFThe high volatility of the price of cobalt and the geopolitical limitations of cobalt mining have made the elimination of Co a pressing need for the automotive industry. Owing to their high energy density and low-cost advantages, high-Ni and low-Co or Co-free (zero-Co) layered cathodes have become the most promising cathodes for next-generation lithium-ion batteries. However, current high-Ni cathode materials, without exception, suffer severely from their intrinsic thermal and chemo-mechanical instabilities and insufficient cycle life.
View Article and Find Full Text PDFThis descriptive case series retrospectively reviewed medical records from thirty-one previously healthy, war-fighting veterans who self-reported exposure to airborne hazards while serving in Iraq and Afghanistan between 2003 and the present. They all noted new-onset dyspnea, which began during deployment or as a military contractor. Twenty-one subjects underwent non-invasive pulmonary diagnostic testing, including maximum expiratory pressure (MEP) and impulse oscillometry (IOS).
View Article and Find Full Text PDFLaser powder bed fusion (LPBF) is a method of additive manufacturing characterized by the rapid scanning of a high powered laser over a thin bed of metallic powder to create a single layer, which may then be built upon to form larger structures. Much of the melting, resolidification, and subsequent cooling take place at much higher rates and with much higher thermal gradients than in traditional metallurgical processes, with much of this occurring below the surface. We have used in situ high speed X-ray diffraction to extract subsurface cooling rates following resolidification from the melt and above the β-transus in titanium alloy Ti-6Al-4V.
View Article and Find Full Text PDFLithium-metal deposition on graphite anodes limits the cycle life and negatively impacts safety of the current state of the art Li-ion batteries. Herein, deliberate interfacial modification of graphite electrodes via direct current (DC) magnetron sputtering of nanoscale layers of Cu and Ni is employed to increase the overpotential for Li deposition and suppress Li plating under high rate charge conditions. Due to their nanoscale, the deposited surface films have minimal impact (∼0.
View Article and Find Full Text PDFACS Appl Mater Interfaces
June 2019
FeO nanoparticles (NPs) with an average size of 8-10 nm have been successfully functionalized with various surface-treatment agents to serve as model systems for probing surface chemistry-dependent electrochemistry of the resulting electrodes. The surface-treatment agents used for the functionalization of FeO anode materials were systematically varied to include aromatic or aliphatic structures: 4-mercaptobenzoic acid, benzoic acid (BA), 3-mercaptopropionic acid, and propionic acid (PA). Both structural and electrochemical characterizations have been used to systematically correlate the electrode functionality with the corresponding surface chemistry.
View Article and Find Full Text PDFLaser powder bed fusion additive manufacturing is an emerging 3D printing technique for the fabrication of advanced metal components. Widespread adoption of it and similar additive technologies is hampered by poor understanding of laser-metal interactions under such extreme thermal regimes. Here, we elucidate the mechanism of pore formation and liquid-solid interface dynamics during typical laser powder bed fusion conditions using in situ X-ray imaging and multi-physics simulations.
View Article and Find Full Text PDFIn situ X-ray-based measurements of the laser powder bed fusion (LPBF) additive manufacturing process produce unique data for model validation and improved process understanding. Synchrotron X-ray imaging and diffraction provide high resolution, bulk sensitive information with sufficient sampling rates to probe melt pool dynamics as well as phase and microstructure evolution. Here, we describe a laboratory-scale LPBF test bed designed to accommodate diffraction and imaging experiments at a synchrotron X-ray source during LPBF operation.
View Article and Find Full Text PDFTypical X-ray diffraction measurements are made by moving a detector to discrete positions in space and then measuring the signal at each stationary position. This step-scanning method can be time-consuming, and may induce vibrations in the measurement system when the motors are accelerated and decelerated at each position. Furthermore, diffraction information between the data points may be missed unless a fine step-scanning is used, which further increases the total measurement time.
View Article and Find Full Text PDFThe oxidation of nickel powder under a controlled gas and temperature environment was studied using synchrotron-based full-field transmission X-ray microscopy. The use of this technique allowed for the reaction to be imaged in situ at 55 nm resolution. The setup was designed to fit in the limited working distance of the microscope and to provide the gas and temperature environments analogous to solid oxide fuel cell operating conditions.
View Article and Find Full Text PDFA serious complication of bisphosphonate (BP) therapy is BP-related osteonecrosis of the jaw (BRONJ). Currently, no biomarkers exist to identify patients at risk. We evaluated whether interleukin-17 and C-telopeptide correlate with BRONJ development.
View Article and Find Full Text PDFAdvances in the design of materials for energy storage and conversion (i.e., "energy materials") increasingly rely on understanding the dependence of a material's performance and longevity on three-dimensional characteristics of its microstructure.
View Article and Find Full Text PDFOral Surg Oral Med Oral Pathol Oral Radiol
February 2013
Objective: We hypothesized that patients with bisphosphonate (BP)-related osteonecrosis of the jaw (BRONJ) accumulate higher levels of BP in bone than those without BRONJ.
Study Design: Using the Pmetrics package and published data, we designed a population pharmacokinetic model of pamidronate concentration in plasma and bone and derived a toxic bone BP threshold of 0.2 mmol/L.
Nano-structures of nickel (Ni) and nickel subsulfide (Ni(3)S(2)) materials were studied and mapped in 3D with high-resolution x-ray nanotomography combined with full field XANES spectroscopy. This method for characterizing these phases in complex microstructures is an important new analytical imaging technique, applicable to a wide range of nanoscale and mesoscale electrochemical systems.
View Article and Find Full Text PDFAmelogenin self-assembles to form an extracellular protein matrix, which serves as a template for the continuously growing enamel apatite crystals. To gain further insight into the molecular mechanism of amelogenin nanosphere formation, we manipulated the interactions between amelogenin monomers by altering pH, temperature, and protein concentration to create isolated metastable amelogenin oligomers. Recombinant porcine amelogenins (rP172 and rP148) and three different mutants containing only a single tryptophan (Trp(161), Trp(45), and Trp(25)) were used.
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