A5025197986- Atomic and Subatomic Physics Research
- Nuclear Physics and Applications
- Quantum, superfluid, helium dynamics
- Advanced NMR Techniques and Applications
- Radiation Detection and Scintillator Technologies
- Particle physics theoretical and experimental studies
- Nuclear physics research studies
- Neutrino Physics Research
- Cold Atom Physics and Bose-Einstein Condensates
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Radioactive Decay and Measurement Techniques
- Particle Detector Development and Performance
- Advanced MRI Techniques and Applications
- Nuclear reactor physics and engineering
- Dark Matter and Cosmic Phenomena
- Wastewater Treatment and Nitrogen Removal
- Enzyme function and inhibition
- Medical Imaging Techniques and Applications
- Cold Fusion and Nuclear Reactions
- Chemical Reactions and Isotopes
- Wood Treatment and Properties
- Race, History, and American Society
- Pharmaceutical and Antibiotic Environmental Impacts
- Meat and Animal Product Quality
Hamilton College
2010-2024
Tulane University
2005-2021
University of Warwick
2013
National Institute of Standards and Technology
1998-2011
University of Surrey
2009
DePauw University
2005
Harvard University
2005
Indiana University Bloomington
2000-2005
Kurchatov Institute
2005
University of Sussex
2005
SUMMARY: Examination of the growth kinetics Bacterium NCIB 8250 in a two-stage continuous culture showed that this organism on phenol could be accounted for by Haldane function substrate inhibition. The magnitude constants (K s < 1 mg/l; and K i, 110 mg/l) was such inhibition dominant factor governing even at concentrations less than 10 mg/l. maintenance requirement high (0.24 to 0.28 g/g h), probably owing energy rupture aromatic nucleus substrate. influence treatment inhibitory wastes...
The NPDGamma collaboration reports results from the first phase of a measurement parity violating up-down asymmetry Aγ with respect to neutron spin direction γ rays emitted in reaction n⃗+p→d+γ using capture polarized cold neutrons on protons liquid parahydrogen target. One expects parity-odd effects hadronic weak interaction between nucleons be induced by quarks. is dominated ΔI=1, 3S1-3P1 transition amplitude n-p system. was completed at Los Alamos Neutron Science Center spallation source...
We report the first result for electron-antineutrino angular correlation ($a$ coefficient) in free neutron $\ensuremath{\beta}$ decay from aCORN experiment. uses a novel method which $a$ coefficient is proportional to an asymmetry proton time of flight events where electron and recoil are detected delayed coincidence. Data presented 15 month run at NIST Center Neutron Research. obtained...
The aCORN experiment measures the neutron-decay electron-antineutrino correlation ($a$ coefficient) using a novel method based on an asymmetry in proton time-of-flight for events where beta electron and recoil are detected delayed coincidence. We report data analysis result from second run at NIST Center Neutron Research, high-flux cold neutron beam new NG-C guide end position:...
We report the results of an improved determination triple correlation $D P \cdot(p_{e}\times p_{\nu})$ that can be used to limit possible time-reversal invariance in beta decay polarized neutrons and constrain extensions Standard Model. Our result is $D=(-0.96\pm 1.89 (stat)\pm 1.01 (sys))\times 10^{-4}$. The corresponding phase between g_A g_V $\phi_{AV} = 180.013^\circ\pm0.028^\circ$ (68 % confidence level). This represents most sensitive measurement D decay.
Over a period of well over decade, large number and variety polarized 3He cells for neutron applications have been developed tested at the U.S. National Institute Standards Technology (NIST). These primarily employed spin-exchange optical pumping (SEOP), applied to scattering fundamental physics. We describe procedures we producing these cells, as their characteristics applications. Whereas our best results are blown from boron-free aluminosilicate glass, summarize with range other methods....
Background: Time-reversal-invariance violation, or equivalently CP may explain the observed cosmological baryon asymmetry as well signal physics beyond Standard Model. In decay of polarized neutrons, triple correlation D<J_{n}>\cdot(p_{e}\timesp_{\nu}) is a parity-even, time-reversal- odd observable that uniquely sensitive to relative phase axial-vector amplitude with respect vector amplitude. The also possible contributions from scalar and tensor amplitudes. Final-state effects contribute D...
Motivated by applications to neutron spin filters and recent advances in spectrally narrowed laser diode arrays (LDAs), we are exploring exchange optical pumping of He3 at pressures near 1 bar. Among our more interesting results has been the production glass cells with extremely long relaxation times. The best these a lifetime T1=840 h [where polarization decays versus time, t, as exp(−t/T1)], dominated dipole–dipole contribution 950 partial pressure 0.85 Using broadband LDA, have obtained...
Abstract Conventional nuclear ventilation/perfusion (V/Q) scanning is limited in spatial resolution and requires exposure to radioactivity. The acquisition of pulmonary V/Q images using MRI overcomes these difficulties. When inhaled, hyperpolarized helium‐3 ( 3 He) permits gas distribution. Magnetic labeling blood (arterial spin‐tagging (AST)) provides perfusion. Three normal subjects, two patients who had undergone single lung transplantation for emphysema, one subject with embolism (PE),...
We describe an experiment that has set new limits on the time reversal invariance violating D coefficient in neutron beta-decay. The emiT measured angular correlation J . p_e x p_p using octagonal symmetry optimizes electron-proton coincidence rates. result is D=[-0.6+/-1.2(stat)+/-0.5(syst)]x10^(-3). This improves constraints phase of g_A/g_V and contributions to T violation due leptoquarks. paper presents details experiment, data analysis, investigation systematic effects.
A neutron spin filter based on transmission through nuclear-spin-polarized 3 He gas has been applied to polarization analysis of small angle scattering (SANS). Such filters, which are the large dependence absorption neutrons by He, make SANS possible because their angular acceptance. In present experiment, a He-based analyzer was employed separate nuclear into its coherent and spin-incoherent components. Polarized analyzers were prepared two different optical pumping methods installed NG3...
High precision fundamental neutron physics experiments have been proposed for the intense pulsed spallation beams at JSNS, LANSCE, and SNS to test standard model search new physics. Certain systematic effects in some of these be controlled few ppb level. The NPDGamma experiment, a small parity-violating $\ensuremath{\gamma}$-ray asymmetry ${A}_{\ensuremath{\gamma}}$ polarized cold capture on parahydrogen, is one example. For experiment we developed radio-frequency resonant spin rotator...
SUMMARY: Further evidence for the inclusion of polythionates in pathway thiosulphate oxidation by members genus Thiobacillus is presented. Manometric experients showed tetrathionate to be a stage tspensions T. thioparus and thiocyanoxidans. accumulated sufficient concentration polythionate medium allow chromatorams prepared, type was influenced ratio between sodium potassium ions medium. The restriction at lower concentrations K+ may due entry phosphate into cell during growth; this discussed.
Hyperpolarized gas magnetic resonance imaging has recently emerged as a method to image lungs, sinuses, and the brain. The best lung images date have been produced using hyperpolarized 3He, which is by either spin-exchange or metastability-exchange optical pumping. For MRI, metastable demonstrated higher polarization levels polarizing rates, but it requires compression of gas. Prior this work, had only accomplished large, complex expensive apparatus. Here, human ventilation are presented...
Nuclear spin-polarized (3)He gas at pressures on the order of 100 kPa (1 bar) are required for several applications, such as neutron spin filters and magnetic resonance imaging. The metastability-exchange optical pumping (MEOP) method polarizing can rapidly produce highly polarized gas, but best results obtained much lower pressure (~0.1 kPa). We describe a compact compression apparatus that is based modified commercial diaphragm pump. by MEOP typical 0.25 (2.5 mbar), compressed into storage...