Heterogeneous catalysts that contain bimetallic nanoparticles may undergo segregation of the metals, driven by oxidizing and reducing environments. The structure composition core-shell Rh(0.5)Pd(0.5) Pt(0.5)Pd(0.5) nanoparticle were studied in situ, during oxidizing, reducing, catalytic reactions involving NO, O2, CO, H2 x-ray photoelectron spectroscopy at near-ambient pressure. underwent dramatic reversible changes chemical state response to or conditions. In contrast, no substantial Pd Pt...

A novel high surface area heterogeneous catalyst based on solution phase colloidal nanoparticle chemistry has been developed. Monodisperse platinum nanoparticles of 1.7−7.1 nm have synthesized by alcohol reduction methods and incorporated into mesoporous SBA-15 silica during hydrothermal synthesis. Characterization the Pt/SBA-15 catalysts suggests that Pt particles are located within surfactant micelles formation leading to their dispersion throughout structure. After removal templating...

The recent discovery of "black" TiO2 nanoparticles with visible and infrared absorption has triggered an explosion interest in the application a diverse set solar energy systems; however, what black nanoparticle really is remains mystery. Here we elucidate more properties try to understand inner workings hydrogenated disorders surface layer surrounding crystalline core. Contrary traditional findings, Ti(3+) here not responsible for TiO2, while there evidence mid-gap states above valence band...

The increased availability of labeled X-ray image archives (e.g. ChestX-ray14 dataset) has triggered a growing interest in deep learning techniques. To provide better insight into the different approaches, and their applications to chest classification, we investigate powerful network architecture detail: ResNet-50. Building on prior work this domain, consider transfer with without fine-tuning as well training dedicated from scratch. leverage high spatial resolution data, also include an...

Perovskite oxides have high catalytic activities for oxygen electrocatalysis competitive to platinum at elevated temperatures. However, little is known about the oxide surface chemistry that influences activity near ambient partial pressures, which hampers design of highly active catalysts many clean-energy technologies such as solid fuel cells. Using in situsynchrotron-based, pressure X-ray photoelectron spectroscopy study changes, we show coverage secondary phases on a (001)-oriented...

Three series of bimetallic nanoparticle catalysts (Rh(x)Pd(1-x), Rh(x)Pt(1-x), and Pd(x)Pt(1-x), x = 0.2, 0.5, 0.8) were synthesized using one-step colloidal chemistry. X-ray photoelectron spectroscopy (XPS) depth profiles different energies scanning transmission electron microscopy showed that the as-synthesized Rh(x)Pd(1-x) Pd(x)Pt(1-x) nanoparticles have a core-shell structure whereas Rh(x)Pt(1-x) alloys are more homogeneous in structure. The evolution their structures chemistry under...

During the past decade, application of ambient pressure photoemission spectroscopy (APPES) has been recognized as an important in situ tool to study environmental and materials science, energy related many other fields. Several APPES endstations are currently under planning or development at USA international light sources, which will lead a rapid expansion this technique. The present work describes design performance new instrument Advanced Light Source beamline 9.3.2 Lawrence Berkeley...

The smaller, the better: In situ synchrotron ambient pressure X-ray photoelectron spectroscopy allows examination of oxidation state surface rhodium nanoparticles (NPs) during CO in an O2 atmosphere. 2 nm NPs oxidize to a larger extent than 7 reaction at 150–200 °C, which correlates with fivefold increase turnover frequency for smaller nanoparticles. Detailed facts importance specialist readers are published as "Supporting Information". Such documents peer-reviewed, but not copy-edited or...

PURPOSE: To evaluate the effect of heart rate on quality coronary angiograms obtained with 16–detector row computed tomography (CT) by using temporally enhanced three-dimensional (3D) approaches. MATERIALS AND METHODS: The local ethics committee approved study, and informed consent was from all patients. Fifty patients underwent CT angiography (heart range, 45–103 beats per minute). Raw data helical electrocardiography (ECG) were saved in a combined set. Retrospectively ECG-gated images...

Monodisperse sub-10 nm Rh nanocubes were synthesized with high selectivity (>85%) by a seedless polyol method. The {100} faces of the NCs effectively stabilized chemically adsorbed Br- ions from trimethyl(tetradecyl)ammonium bromide (TTAB). This simple one-step route can be readily applied to preparation Pt and Pd nanocubes. Moreover, organic molecules PVP TTAB that encapsulated did not prevent catalytic activity for pyrrole hydrogenation CO oxidation.

Recent breakthroughs in synthesis nanoscience have achieved control of size and composition nanoparticles that are relevant for catalyst design. Here, we show the catalytic activity CO oxidation by Rh/Pt bimetallic can be changed varying at a constant (9 ± 1 nm). Two-dimensional nanoparticle arrays were formed on silicon surface via Langmuir−Blodgett technique. Composition analysis with X-ray photoelectron spectroscopy agrees reaction stoichiometry Rh/(Pt + Rh). rates exhibit 20-fold...

Trivalent cerium ions in CeO2 are the key active species a wide range of catalytic and electro-catalytic reactions. We employed ambient pressure X-ray photoelectron spectroscopy electrochemical impedance to quantify simultaneously concentration reactive Ce3+ on surface bulk Sm-doped CeO2(100) hundreds millitorr H2–H2O gas mixtures. Under relatively oxidizing conditions, when is almost entirely 4+ oxidation state, reduced can be over 180 times concentration. Furthermore, stark contrast bulk,...

Size-tunable monodisperse Rh nanocrystals can offer unique properties for many heterogeneous catalytic reactions (such as hydrogenation, hydroformylation, and hydrocarbonylation) of both scientific technological interest. In this article, we report the synthesis monodisperse, well-shaped in a range 5−15 nm by one-step polyol reduction at temperatures 170−230 °C under Ar, using rhodium(III) acetylacetonate [Rh(acac)3] source metal ions, 1,4-butanediol reducing solvent, poly(vinylpyrrolidone)...

Many interesting structures have been observed for O2-exposed Pt(110). These structures, along with their stability and reactivity toward CO, provide insights into catalytic processes on open Pt surfaces, which similarities to nanoparticle catalysts. In this study, we present results from ambient-pressure X-ray photoelectron spectroscopy, high-pressure scanning tunneling microscopy, density functional theory calculations. At low oxygen pressure, only chemisorbed is the Pt(110) surface....

This study controllably reduces the silicon dioxide (SiO2) layer on Si nanoparticles and evaluates its effect performance of nanoparticle-based electrodes in Li-ion batteries. Various thicknesses this native oxide are present generated by chemical vapor deposition (CVD) due to process conditions exposure oxygen during storage. can be effectively reduced hydrofluoric acid (HF) etching, which results improved electrochemical over as-received samples. As-received sample has a higher first-cycle...

Improving the oral absorption of compounds with low aqueous solubility is a common challenge that often requires an enabling technology. Frequently, can be improved by formulating compound as amorphous solid dispersion (ASD). Upon dissolution, ASD reach higher concentration unbound drug than crystalline form, and generates large number sub-micrometer, rapidly dissolving drug-rich colloids. These colloids have potential to decrease diffusional resistance across unstirred water layer...

The size-tunable synthesis of poly(vinylpyrrolidone)-stabilized cuboctahedral rhodium nanoparticles with mean diameters ranging between 3-7 nm and multipod structures was accomplished using seeded growth methods. Isotropic PVP-capped 2.9 seeds were prepared by ligand exchange on rhodium-triphenylphosphine metal-organic clusters. Quantitative investigation reaction parameters in ethylene glycol revealed that size shape could be controlled at a single temperature 120 degrees C. rate monomer...

Through the use of ambient pressure X-ray photoelectron spectroscopy (APXPS) and a single-sided solid oxide electrochemical cell (SOC), we have studied mechanism electrocatalytic splitting water (H2O + 2e(-) → H2 O(2-)) electro-oxidation hydrogen (H2 O(2-) H2O 2e(-)) at ∼700 °C in 0.5 Torr H2/H2O on ceria (CeO2-x) electrodes. The experiments reveal transient build-up surface intermediates (OH(-) Ce(3+)) show separation charge gas-solid interface exclusively electrochemically active region...

Ambient pressure X-ray photoelectron spectroscopy (XPS) is used to measure near-surface oxidation states and local electric potentials of thin-film ceria electrodes operating in solid oxide electrochemical cells for H2O electrolysis H2 oxidation. Ceria which are 300 nm thick deposited on YSZ electrolyte supports with porous Pt counter single-chamber tests H2/H2O mixtures. Between 635 740 °C, equilibrium (zero-bias) between 70 85% Ce3+ confirm increased surface reducibility relative bulk...

Using in situ high-pressure x-ray photoelectron spectroscopy, we have followed the oxidation and reduction of Pd model catalysts oxygen CO pressures millibar range. The study includes a Pd(100) single crystal as well SiO${}_{x}$-supported nanoparticles 15 or 35 nm diameter, respectively. We demonstrate that also form ultrathin surface oxides prior to onset bulk PdO. are observed oxidize at sample temperatures 40 degrees lower than single-crystal surface. In $3{d}_{5/2}$ O $1s$ spectrum,...

The goal of this study was to develop and validate a system for automatic segmentation the spine, pedicle identification, screw path suggestion use with an intraoperative 3D surgical navigation system.

Abstract Objective The aim is to evaluate whether smart worklist prioritization by artificial intelligence (AI) can optimize the radiology workflow and reduce report turnaround times (RTATs) for critical findings in chest radiographs (CXRs). Furthermore, we investigate a method counteract effect of false negative predictions AI—resulting an extremely dangerously long RTAT, as CXRs are sorted end worklist. Methods We developed simulation framework that models current at university hospital...