Search Results - (Author, Cooperation:T. G. Jones)

2013-02-01

Nature Publishing Group (NPG)

0028-0836

1476-4687

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Chemistry and Pharmacology

Medicine

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Physics

*Carbon Cycle ; Carbon Radioisotopes/analysis ; *Conservation of Natural Resources ; Indonesia ; Seasons ; Soil/*chemistry ; Trees/*metabolism

2012-07-17

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

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Animals ; *Archaeology ; *Caves ; DNA/analysis ; Emigration and Immigration/history ; Feces ; *Fossils ; History, Ancient ; Humans ; Molecular Sequence Data ; North America ; Oregon ; Population Dynamics ; Radiometric Dating ; Rodentia ; Technology/history ; Time

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

A simple technique has been developed to image intense pulsed proton beams with radiachromic film and to measure their spatial distribution. The optical density (OD) of 50 μm thick film, sufficient to stop 1.5 MeV protons, is measured to infer the incident beam fluence. The OD increases nearly linearly with fluence up to 0.25 cal/cm2. This film is used to measure the uniformity of large-area beams as well as the detector in a multiple-pinhole camera to determine the source uniformity and divergence of applied-magnetic field and pinched-beam ion diodes. © 1999 American Institute of Physics.

Electronic Resource

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

A novel, spatially resolved diagnostic is being developed to measure magnetic fields associated with intense ion beam propagation through a low-pressure gas, as is envisioned for ion-driven inertial confinement fusion. The diagnostic technique uses laser-induced fluorescence spectroscopy, and can be varied to measure either small or large fields. Small fields, as expected in ballistic beam transport, produce Zeeman shifts, ΔλZ, much smaller than the transition linewidth Δλ. High sensitivity to measure these sub-Doppler shifts is achieved by a variation on the Babcock technique.〈citeref RID="R1" STYLE="SUPERIOR"〉1 Large fields, as expected in self-pinched beam transport, produce ΔλZ larger than Δλ. These ΔλZ will be resolved using a Fabry–Pérot interferometer, in a novel technique similar to that for small fields. Results from benchtop experiments using calibrated B fields for the small-field technique will be presented. Available results from a proof-of-principle experiment for the large-field technique will also be presented.© 1999 American Institute of Physics.

Electronic Resource

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

A novel, spatially and temporally resolved diagnostic is being developed to measure small B fields by detecting Zeeman shifts much smaller than the transition linewidth. This diagnostic technique will be used to measure magnetic fields associated with intense ion beam propagation through a low-pressure gas, as envisioned for particle beam fusion. High sensitivity is achieved by a variation on the Babcock technique using laser-induced fluorescence (LIF) spectroscopy. The LIF from a J=1→0 transition in a probe species is viewed parallel to B. In this direction, ΔM=0 fluorescence is not observed, while ΔM=±1 fluorescence is right- and left-circularly polarized and can be measured separately using polarization filters. If a narrow-band pump laser is tuned to a half-maximum point of the unsplit transition line, the presence of the magnetic field shifts one of the ΔM=±1 absorption transitions into resonance with the laser and shifts the other transition further out of resonance. For small field strengths, the difference in the fluorescence signals is proportional to the Zeeman split. © 1997 American Institute of Physics.

Electronic Resource

1432-5225

Springer Online Journal Archives 1860-2000

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Summary Non-steady state desorption of dissolved carbon dioxide gas from green Nothofagus fusca heartwoood boards saturated with carbon dioxide gas at a pressure of 1.5 MPa was used to measure transverse dissolved carbon dioxide gas diffusivities at 1, 20 and 30 °C. Mean transverse diffusion coefficients were 0.6×10-11m2s-1 at 1 °C, 4.2×10-11m2s-1 at 20 °C, and 8.4×10-11m2s-1 at 30 °C. These are 0.6, 2.5 and 3.8% of the dissolved carbon dioxide gas diffusivities in water at 1, 20 and 30 °C respectively. The activation energy of dissolved carbon dioxide gas diffusion in green N. fusca heartwood is 59. 4 kJ mol-1. This is three times the activation energy of dissolved carbon dioxide gas diffusion in water. This suggests the presence of a reaction mechanism between the dissolved carbon dioxide molecules and the cell wall constituents.

Electronic Resource