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Magnetized Liner Inertial Fusion experiments have been performed at the Z facility at Sandia National Laboratories. These experiments use deuterium fuel, which produces 2.45 MeV neutrons on reaching thermonuclear conditions. To study the spatial structure of neutron production, the one-dimensional imager of neutrons diagnostic was fielded to record axial resolved neutron images. In this diagnostic, neutrons passing through a rolled edge aperture form an image on a CR-39-based solid state nuclear track detector. Here, we present a modified generalized expectation–maximization algorithm to reconstruct an axial neutron emission profile of the stagnated fusion plasma. We validate the approach by comparing the reconstructed neutron emission profile to an x-ray emission profile provided by a time-integrated pinhole camera. [ABSTRACT FROM AUTHOR]

Black rot of sweetpotato, caused by Ceratocystis fimbriata, has recently reemerged as a significant threat to sweetpotato production in North Carolina and other states across the United States. This disease has historically been controlled largely through cultural management strategies and. in some cases, fungicide application. The sudden and destructive reemergence of this disease in 2015 created the need for rapidly evaluating disease control strategies. Genetic diversity of current C. fimbriata isolates infecting sweetpotato in North Carolina was assessed using ITS, TEF, and MAT-2 sequences. All 50 tested isolates were confirmed to be of a single mating type, MAT-2, based on PCR amplification. Alignment of ITS, TEF, and MAT-2 sequences revealed all isolates were identical at each locus. Fourteen common sweetpotato cultivars and advanced breeding lines were screened for black rot resistance using two isolates. None of the cultivars were completely resistant to the disease and most were equally susceptible. 'Stokes Purple' and 'Covington' were the least susceptible, but significantly (P < 0.05) differed only from 'Bellevue', the most susceptible cultivar. Sensitivity of 50 C. fimbriata isolates to difenoconazole, fludioxonil, thiabendazole, dicloran, azoxystrobin, pyraclostrobin, fenamidone, and fluazinam was evaluated in vitro. Difenoconazole, thiabendazole, and fluazinam were most effective in reducing mycelia growth. Postharvest fungicide application on black rot-infected roots provided similar results. Low efficacy of dicloran, as well as a range of EC5() values among isolates, suggests potential resistance to this commonly applied fungicide. Results obtained in this study provide current and useful information so that improved recommendations can be made to reduce losses in sweetpotato to black rot. [ABSTRACT FROM AUTHOR]

The 1-D one-speed slab-geometry PNequations with isotropic scattering can be modified via an alternative moment closure to preserve the two asymptotic eigenmodes associated with the transport equation. Pomraning referred to these equations as the asymptotic PNequations. It is well-known that the 1-D slab-geometry SN+1equations with Gauss quadrature are equivalent to the standard PNequations. In this article, we first show that if any quadrature set meets a certain criterion, the corresponding SN+1equations will be equivalent to a set of PNequations with a quadrature-dependent closure. We then derive a particular family of quadrature sets that make the SN+1equations equivalent to the asymptotic PNequations. Next we theoretically demonstrate several of the properties of these sets, relate them to an existing family of quadratures, numerically generate several example quadrature sets, and give numerical results that confirm several of their theoretically predicted properties. [ABSTRACT FROM PUBLISHER]

The final Z-pinch stage of a dense plasma focus (DPF) could be used as a simple, compact, and potentially rugged plasma-based high-gradient accelerator with fields at the 100-MV/m level. In this paper, we review previously published experimental beam data that indicate the feasibility of such a DPF-based accelerator, qualitatively discuss the physical acceleration processes in terms of the induced voltages, and as a starting point, examine the DPF acceleration potential by numerically applying a self-consistent DPF system model that includes the induced voltage from both macroscopic and instability-driven plasma dynamics. Applications to the remote detection of high explosives and a multistaged acceleration concept are briefly discussed. [ABSTRACT FROM AUTHOR]

This paper introduces yellowness index (YI) as a measure for chlorosis of leaves in stressed plants. YI provides a measure of the change in shape of the reflectance spectra between the maximum near 0.55 mu m and the minimum near 0.65 mu m. Quantitatively, YI is a simple, three-point approximation of the second derivative of the spectra, calculated using a finite divided difference approximation. YI is compared with two vegetation indices based on spectral changes in the region of the red edge, VI and NDVI. For manganese-deficient soybean leaves, YI, VI and NDVI were all closely related to leaf chlorophyll concentrations. YI is calculated from wavelengths in the visible that are thought to be less sensitive to changes in leaf structure or water content. Because YI is an approximation of a spectral second derivative, it should be less sensitive to atmospheric effects than many other vegetation indices. Finally, although the results reported here are promising, they are based on leaf-level observations and must be verified at the canopy level for remote sensing applications. An example of the correlation between NDVI and YI in AVIRIS data is given. [ABSTRACT FROM AUTHOR]

Dynamics of rotating machinery has long been an active field of study and research because of its importance to a wide variety of applications. Extensive analysis of complex machinery configurations is now a routine practice in many quarters as a result of advancements in computerized methods. However, basic physical insights are often obscured in the presence of enormous computational power. To a large extent, this is because certain fundamental properties of rotor-bearing systems have not been sufficiently exposed in the literature, in contrast to computational methods and results. Specifically, the equations of motion for typical rotor-bearing systems [MX, + CX + KX = F(t)l frequently result in nonsymmetric C and K matrices. Decomposition into symmetric and skew-symmetric matrices can readily be shown to amount to a separation of conservative and non-conservative interactive force fields [see M. L. Adams and J. Padovan, 'Insights Into Linearized Rotor Dynamics,' J. Sound Vib. (in press)]. The skew-symmetric portion of K embodies a nonconservative circulatory force field which is responsible for classical rotor-bearing instability. The skew-symmetric portion of C embodies a conservative force field which produces spectrum bifurcation, e.g., gyroscopic and fluid-annulus inertia effects. [ABSTRACT FROM AUTHOR]