A5017648594- X-ray Spectroscopy and Fluorescence Analysis
- Astro and Planetary Science
- Nuclear Physics and Applications
- Mass Spectrometry Techniques and Applications
- Ion-surface interactions and analysis
- Planetary Science and Exploration
- Mycotoxins in Agriculture and Food
- Lichen and fungal ecology
- Radiopharmaceutical Chemistry and Applications
- Indoor Air Quality and Microbial Exposure
- Geology and Paleoclimatology Research
- Metal-Organic Frameworks: Synthesis and Applications
- Medical Imaging Techniques and Applications
- Stellar, planetary, and galactic studies
- Analytical chemistry methods development
- Adaptive optics and wavefront sensing
- Electron and X-Ray Spectroscopy Techniques
- Spacecraft and Cryogenic Technologies
- Advanced Proteomics Techniques and Applications
- Astronomy and Astrophysical Research
- Atmospheric chemistry and aerosols
- Boron Compounds in Chemistry
- Radioactivity and Radon Measurements
- Trace Elements in Health
- Gamma-ray bursts and supernovae
Lawrence Livermore National Laboratory
2001-2012
University of California, Davis
2007
Drexel University
2007
SUNY Plattsburgh
2006
State University of New York
2006
European Synchrotron Radiation Facility
2006
Institut d'Astrophysique Spatiale
2006
Goethe University Frankfurt
2006
Jet Propulsion Laboratory
2006
Campus France
2006
Pan-STARRS1 has carried out a set of distinct synoptic imaging sky surveys including the $3π$ Steradian Survey and Medium Deep in 5 bands ($grizy_{P1}$). The mean 5$σ$ point source limiting sensitivities stacked 3$π$ $grizy_{P1}$ are (23.3, 23.2, 23.1, 22.3, 21.4) respectively. upper bound on systematic uncertainty photometric calibration across is 7-12 millimag depending bandpass. astrometric using Gaia frame comes from comparison results with Gaia: standard deviation median residuals ($...
The Stardust spacecraft collected thousands of particles from comet 81P/Wild 2 and returned them to Earth for laboratory study. preliminary examination these samples shows that the nonvolatile portion is an unequilibrated assortment materials have both presolar solar system origin. contains abundance silicate grains are much larger than predictions interstellar grain models, many high-temperature minerals appear formed in inner regions nebula. Their presence a proves formation included...
We measured the elemental compositions of material from 23 particles in aerogel and residue seven craters aluminum foil that was collected during passage Stardust spacecraft through coma comet 81P/Wild 2. These are chemically heterogeneous at largest size scale analyzed (â¼180 ng). The mean composition this Wild 2 is consistent with CI meteorite composition, which thought to represent bulk solar system, for elements Mg, Si, Mn, Fe, Ni 35%, Ca Ti 60%. Cu, Zn, Ga appear enriched material,...
Metal-organic frameworks containing an organic fluorophore such as stilbene dicarboxylate emit prompt visible light when they interact with ionizing radiation (e.g., high-energy protons or alpha particles). A completely new class of scintillation materials is created by this development, the potential to rationally tailor properties for specific detection applications. Detailed facts importance specialist readers are published "Supporting Information". Such documents peer-reviewed, but not...
Previously, hydrated sodium calcium aluminosilicate (HSCAS), a phyllosilicate clay of the smectite class, was shown to tightly bind aflatoxins and prevent aflatoxicosis in animals. HSCAS is commercial feed additive that approved be used as an anticaking agent. In this study, aflatoxin B1 (AfB1) isothermally mixed with at 15, 25, 37 °C study adsorption process. An L isotherm characterized from data, which were fitted multiple equations (i.e., Langmuir, multi-Langmuir, general Freundlich,...
Acidic montmorillonite clay was chemically modified via exchange with various ammonium- and pyridinium-based organic cations. These organo clays were then shown to adsorb zearalenone (ZEN) an efficacy related the exchanged cation hydrophobicity, as gauged by estimated critical micelle concentration values (cmc) length of alkyl chain. ZEN adsorption greatest for samples that had been interlayer cations possessing 16-carbon chains: hexadecyltrimethylammonium (HDTMA) cetylpyridinium (CP)....
In January 2006, the Stardust mission will return first samples from a solid solar-system body since Apollo, and of contemporary interstellar dust ever collected. Although sophisticated laboratory instruments exist for analysis samples, techniques recovery particles particle residues aerogel collectors remain primitive. Here we describe our recent progress in developing extracting small volumes aerogel, which have called ``keystones,'' completely contain impacts but minimize damage to...
Older men tend to have poorer semen quality and are generally at higher risks for infertility abnormal reproductive outcomes.We employed proton-induced X-ray emission (PIXE, 3 MeV proton beam) investigate the concentrations of zinc, copper, calcium, sulfur, chlorine, potassium, titanium, iron nickel in washed sperm seminal plasma from non-smoking groups 10 older (65-80 years old) younger (22-28 who were concurrently assayed function genomicly defective sperm.The group showed elevated copper...
Standard isotherm equations do not estimate capacity (Qmax) and distribution coefficient (Kd) for complex or non-Langmuir-shaped plots. In this study, two mycotoxins, that is, aflatoxin B1 (AfB1) cyclopiazonic acid (CPA), were mixed with kaolinite a naturally acidic montmorillonite clay (LPHM) at 25 °C, respectively. Isotherm data gave S-type The fitted to the models of Langmuir (LM) multi-Langmuir (MLM); however, these did provide good fit displayed multisite adsorption multiple plateaus....
A method has been developed for measuring profiles of aerosol mass on thin (480 w g/cm 2 ) Apiezon-L coated Mylar films employed in rotating drum impactor samplers using the ion beam analysis technique scanning transmission microscopy (STIM). The greased are excellent impaction substrates and possess uniformity projected density, making them an ideal substrate STIM analysis. density a film enables with 3 MeV proton to produce accuracy better than 90% sensitivity approaching 10 . Further, we...
Although studies have demonstrated that zinc can bind to sperm nuclear proteins, specifically protamine 2, it has not been shown the metal is sufficiently abundant inside nucleus interact stoichiometrically with these proteins. In this study proton-induced X-ray emission (PIXE) used measure amount of sulfur and within nuclei individual cells infer stoichiometry binding 2 in six species mammal: bull, chinchilla, stallion, hamster, human, mouse (protamine comprises from 0% (bull) 67% (mouse)...
Neurotoxicity from chronic metal inhalation has been suggested as an underlying contributor to late-developing neurodegenerative diseases that have symptoms similar Alzheimer's and Parkinson's syndromes. If inhaled metals contribute pathogenesis of these diseases, identifying, localizing, quantitating deposition(s) within specific target regions the central nervous system will be critical our understanding mechanisms. Standard analytical techniques used date require exposure extremely high...
The collapse of the World Trade Center (WTC) buildings #2 (South Tower), #1 (North and #7 created an enormous pile which emitted intense plumes acrid smoke dust until roughly mid-December, when last spontaneous surface fire occurred. We collected particles by size (8 modes, ≈12 to 0.09 micrometers diameter) time (typical resolution 1 3 h) from October 2 late December at EML 201 Varick Street site 1.8 km NNE 50 m above ground level. Here we show some 70,000 mass elemental data period through...
ABSTRACT We evaluate two dominant nuclear reaction rates and their uncertainties that affect 44 Ti production in explosive nucleosynthesis. Experimentally we develop thick target yields for the 40 Ca(α, γ) at E α = 4.13, 4.54, 5.36 MeV using γ-ray spectroscopy. At highest beam energy, also performed an activation measurement which agrees with result. From measured a stellar rate was developed is smaller than current statistical-model calculations recent experimental results, would suggest...
A cross section of the vagrant soil lichen Xanthoparmelia chlorochroa was analyzed using proton microprobe PIXE. Data were used to generate quantitative, two‐dimensional element distribution maps for Al, Si, P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, and Sr. Element show differential partitioning between stratified layers thallus. These data document transfer inorganic nutrients across thallus algal layer. Inorganic particle entrapment also evident in maps. Dense accumulations calcium...