A Portable Optical Planimeter for Measuring Leaf Area

Author Institution: Department of Botany, Ohio University, Athens, Ohi

Ecological effects and environmental fate of solid rocket exhaust

Specific target processes were classified as to the chemical, chemical-physical, and biological reactions and toxic effects of solid rocket emissions within selected ecosystems at Kennedy Space Center. Exposure of Citris seedlings, English peas, and bush beans to SRM exhaust under laboratory conditions demonstrated reduced growth rates, but at very high concentrations. Field studies of natural plant populations in three diverse ecosystems failed to reveal any structural damage at the concentration levels tested. Background information on elemental composition of selected woody plants from two terrestrial ecosystems is reported. LD sub 50 for a native mouse (peromysous gossypinus) exposed to SRM exhaust was determined to be 50 ppm/g body weight. Results strongly indicate that other components of the SRM exhaust act synergically to enhance the toxic effects of HCl gas when inhaled. A brief summary is given regarding the work on SRM exhaust and its possible impact on hatchability of incubating bird eggs

Multipole methods for nanoantennas design: applications to Yagi-Uda configurations

International audienceWe present a detailed formalism allowing analytical calculations of the radiative properties of nanoantennas. This formalism does not rely on dipole approximations and utilizes multipolar multiple-scattering theory. The improvement in both accuracy and calculation speeds offered by this formulation provides significant advantages that are used in this work to study Yagi-Uda-type nanoantennas. We provide a study that questions the necessity of the reflector particle in nanoantennas

Independent and Combined Effects of Menhaden Oil and High Fructose on Hepatic Lipid Metabolism

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Regeneratively Cooled Liquid Oxygen/Methane Technology Development Between NASA MSFC and PWR

The National Aeronautics & Space Administration (NASA) has identified Liquid Oxygen (LOX)/Liquid Methane (LCH4) as a potential propellant combination for future space vehicles based upon exploration studies. The technology is estimated to have higher performance and lower overall systems mass compared to existing hypergolic propulsion systems. NASA-Marshall Space Flight Center (MSFC) in concert with industry partner Pratt & Whitney Rocketdyne (PWR) utilized a Space Act Agreement to test an oxygen/methane engine system in the Summer of 2010. PWR provided a 5,500 lbf (24,465 N) LOX/LCH4 regenerative cycle engine to demonstrate advanced thrust chamber assembly hardware and to evaluate the performance characteristics of the system. The chamber designs offered alternatives to traditional regenerative engine designs with improvements in cost and/or performance. MSFC provided the test stand, consumables and test personnel. The hot fire testing explored the effective cooling of one of the thrust chamber designs along with determining the combustion efficiency with variations of pressure and mixture ratio. The paper will summarize the status of these efforts

Spectral analysis of three-dimensional photonic jets

International audienceThe spatial and spectral properties of three-dimensional photonic jets are studied in a framework employing rigorous Lorentz-Mie theory. The contributions to the field from each spectral component are studied quantitatively and highlight the distinctive features of photonic jets. In particular, the presence of secondary lobes in the propagative frequency distribution are singled out as a fundamental distinctive property between photonic jets and classical Gaussian beams. It is shown that these differences can lead to divergences of photonic jets at least twice as small as those in corresponding ‘Gaussian' beams