A5064776239- Energetic Materials and Combustion
- High-pressure geophysics and materials
- Diamond and Carbon-based Materials Research
- Combustion and Detonation Processes
- Organic Electronics and Photovoltaics
- Conducting polymers and applications
- Carbon Nanotubes in Composites
- Nuclear Physics and Applications
- Polymer Foaming and Composites
- Boron and Carbon Nanomaterials Research
- Advanced X-ray Imaging Techniques
- Cellular and Composite Structures
- X-ray Spectroscopy and Fluorescence Analysis
- X-ray Diffraction in Crystallography
- Crystallography and molecular interactions
- Physical Activity and Health
- Mobile Health and mHealth Applications
- Graphite, nuclear technology, radiation studies
- Geological and Geochemical Analysis
- Obesity, Physical Activity, Diet
- Fullerene Chemistry and Applications
- Advanced X-ray and CT Imaging
- Elasticity and Material Modeling
- Crystallization and Solubility Studies
- Nanotechnology research and applications
Los Alamos National Laboratory
2016-2024
European Spallation Source
2024
Government of the United States of America
2023
St. Jude Children's Research Hospital
2021-2022
Film Independent
2019
University of California, Los Angeles
2013-2016
Los Angeles City College
2015
California NanoSystems Institute
2015
Brigham Young University - Idaho
2014
Cooper Institute
2009-2012
Abstract Transit through the carbon liquid phase has significant consequences for subsequent formation of solid nanocarbon detonation products. We report dynamic measurements condensation and solidification into nano-onions over ∽200 ns by analysis time-resolved, small-angle X-ray scattering data acquired during a hydrogen-free explosive, DNTF (3,4-bis(3-nitrofurazan-4-yl)furoxan). Further, thermochemical modeling predicts direct to graphite transition products ~200 post-detonation. Solid...
The detonation of carbon-rich high explosives yields solid carbon as a major constituent the product mixture, and depending on thermodynamic conditions behind shock front, variety allotropes morphologies may form evolve. We applied time-resolved small-angle X-ray scattering (TR-SAXS) to investigate dynamics clustering during PBX 9502, an explosive composed 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) 5 wt % fluoropolymer binder. Solid formation was probed from 0.1 2.0 μs front revealed rapid...
The experimental determination of the transmission surface, which represents an approximation to X-rays in crystals, is described. Experimental surfaces are compared with values calculated from crystal shape. Also structural parameters some structures obtained data and without absorption correction compared.
Photoinduction of long-lived polarons Photosynthetic complexes and organic photovoltaics can rapidly create separated charges upon photoexcitation. However, unproductive charge recombination often occurs in the human-made system. This is part because acceptor donor structures are much larger. Huber et al. created aqueous micelles that pair conjugated polyelectrolyte donors with fullerene acceptors at a smaller interface. They observed photoinduced formation polarons—stable pairs charges—with...
Polymer:fullerene bulk heterojunction (BHJ) solar cell active layers can be created by traditional blend casting (BC), where the components are mixed together in solution before deposition, or sequential processing (SqP), pure polymer and fullerene materials cast sequentially from different solutions. Presently, however, relative merits of SqP as compared to BC not fully understood because there has yet an equivalent (composition- thickness-matched layer) comparison between two techniques....
Although most polymer/fullerene-based solar cells are cast from a blend of the components in solution, it is also possible to sequentially process polymer and fullerene layers quasi-orthogonal solvents. Sequential processing (SqP) not only produces photovoltaic devices with efficiencies comparable more traditional bulk heterojunction (BHJ) produced by casting (BC) but offers advantage that can be optimized separately. In this paper, we explore morphology when polymer/fullerene compare BC...
Two n-type semiconducting polymers with alternating arylene (thiophene or selenophene)–tetraazabenzodifluoranthene diimide (BFI) donor–acceptor architecture have been investigated as new electron acceptors in polymer/polymer blend solar cells. The selenophene-linked polymer, PBFI-S, has a significantly smaller optical band gap (1.13 eV) than the thiophene-linked PBFI-T (1.38 eV); however, both similar HOMO/LUMO energy levels determined from cyclic voltammetry. Blends of...
A novel methoxylated 1,4-bisbenzyl fullerene adduct gives better performance in polymer:fullerene bulk heterojunction photovoltaic devices than traditional PCBM, and it is easily synthesized.
The transmission of an incident X-ray beam in a particular direction depends on the absorption properties crystal this direction. A measurement relative all possible directions allows, therefore, principle, determination three-dimensional surface crystal. factor for interest can easily be determined precession or rotation camera if cross section is smaller than size. way may used to correct intensity films obtained under similar geometrical conditions, i.e. screenless photographs. method was...
The efficiency of bulk heterojunction (BHJ) organic photovoltaics is sensitive to the morphology fullerene network that transports electrons through device. This sensitivity makes it difficult distinguish contrasting roles local electron mobility (how easily can transfer between neighboring molecules) and macroscopic well‐connected on device length scales) in solar cell performance. In this work, a combination density functional theory (DFT) calculations, flash‐photolysis time‐resolved...
Time resolved Small Angle X-ray Scattering (SAXS) experiments on detonating explosives have been conducted at Argonne National Laboratory's Advanced Photon Source Dynamic Compression Sector. The purpose of the is to measure SAXS patterns tens ns a few μs behind detonation front. Corresponding positions front are order 0.1–10 mm. From scattering patterns, properties explosive products relative time can be inferred. This report describes how and distance from x-ray probe location calculated,...
Polyethylene is a widely used plastic exhibiting large range of properties that depend on molecular weight, crystallinity, chain branching, and cross-linking. In this study, the sound speeds elastic variety commercially available polyethylene materials were experimentally determined using pulse-echo ultrasound technique. situ pressure dependent measurements, including time flight, x-ray diffraction, radiography, performed Paris-Edinburgh volume press at High Pressure Collaborative Access...
Abstract At the ESS, a large-scale 20 K helium refrigeration system with cooling capacity of 30.3 kW at 15 K, which is called Target Moderator CryoPlant (TMCP), has been designed to cool cryogenic moderator (CMS) where subcooled liquid hydrogen will be circulated 1.0 kg/s through four moderators total nuclear heating estimated 17.2 for proton beam power 5 MW. The first phase TMCP installation and commissioning compressor skids cold box was completed in 2019. 2 300 m-long transfer lines...
The expression of glypican-3 (GPC3), a heparan-sulfate proteoglycan associated with the Simpson-Golabi-Behmel fetal overgrowth syndrome, was studied in normal human placental tissue and cell lines derived from placentae. Cytotrophoblasts term placentae expressed GPC3 mRNA at low levels culture. increased markedly during trophoblast differentiation. By contrast, fibroblast did not express Similarly, choriocarcinoma (BeWo, JAR, JEG) failed to mRNA. In situ hybridization confirmed localization...
Background: The Illinois WISEWOMAN Program (IWP) was designed to address the disproportionate risk of cardiovascular disease (CVD) among disadvantaged, low-income women. In total, 1021 women aged 40 64 years were recruited from Breast and Cervical Cancer Program. randomized either a minimum intervention (MI) or an enhanced (EI) group. Both groups received CVD factor screening educational materials, EI group 12-week lifestyle change intervention. Methods: Demographic clinical data collected...
Products evolved during the detonation of high explosives are primarily a collection molecular gases and solid carbon condensates. Electron microscopy studies have revealed that (soot) can contain variety unique particles possessing novel morphologies, such as onions ribbons. Despite these observations very little is known about conditions leads to production nanoparticles. A fuller understanding on generate nanoparticles would greatly benefit from time-resolved probe particle formation...
Poly(fluorene-alt-thiophene) (PFT) is a conjugated polyelectrolyte that self-assembles into rod-like micelles in water, with the polymer backbone running along length of micelle. At modest concentrations (∼10 mg/mL aqueous solutions), PFT forms hydrogels, and this work focuses on understanding structure intermolecular interactions those gel networks. The network can be directly visualized using cryo electron microscopy. Oscillatory rheology studies further tell us about connectivity within...