lower rate of methyl bromide usage. The tolerance of cabbage, cipollini, garlic, and yams to such fumigation has been discussed by Roth and Richardson {9, 10).Residues in yams (Table III) from atmospheric pressure fumigation (NAP) are variable, but generally lower at 55°F. than at 80°to 86°F. The residue from the vacuum fumigation at 80°F. is about the same as would be produced by an atmospheric fumigation at that temperature. Peas show little temperature dependence in this study. The residue levels in the honeydew melons are all below the level of sensitivity of the x-ray fluorescence method used.Fumigation of apples results in a very low rate of bromide residue accumulation (Table III), similar to peaches and plums (Table I). The residue in blueberries, slightly higher, is comparable with grapes and cherries (Table I).Cabbage accumulates residue at a significantly higher rate, comparable with carrots and peppers (Table I) and yams (Table III). Although the results are not directly comparable because of different chamber loading, the residues on cabbage after 15-inch sustained vacuum fumigation appear slightly higher than those after atmospheric pressure fumigation in two paired tests at 34°and 51°F.

No abstract

We derive coupled partial differential equations that accurately describe the propagation of pseudo-acoustic Pwaves in orthorhombic media but do not require explicit knowledge of shear velocities. These allow extension to orthorhombic media of efficient methods commonly used for modeling and for reverse time migration of P-waves in transversely isotropic media.

Advances in acquisition and processing technology help overcome imaging challenges in complex structural settings. The widespread adoption of wide-azimuth (WAZ) and the move towards full-azimuth (FAZ) acquisition geometries, both combined with increasing offsets, result in significantly improved illumination. Reduced compute cost and improved performance enabled reverse time migration (RTM) to emerge as the imaging algorithm of choice in such settings. Of course, an accurate velocity model is a key component in realizing the full potential of these acquisition geometries and algorithms. The trend is towards increasingly more complex anisotropic models, with a move from vertical transverse isotropy (VTI) to tilted transverse isotropy (TTI) and even orthorhombic. In the Gulf of Mexico (GoM), though the importance of defining an accurate anisotropic model in the supra-salt section cannot be understated, the largest contributing factor to a good image subsalt is often the correct delineation of the "salt body" itself. Without an accurate definition of the salt geometry, the subsalt image invariably remains distorted and poorly resolved. In this paper, we will focus on this portion of the depth imaging workflow and illustrate how the techniques of RTM scenario testing and image partitioning can be used in combination to both help define the salt geometry and improve the final post-migration image. We will describe a practical workflow and the key components that we feel are necessary for its success. In addition, we will illustrate a number of lessons learned during the course of recent projects executed in the GoM.

Field research conducted in 2003 and 2004 evaluated hyperspectral radiometry as a tool to detect localized dry spots on creeping bentgrass (Agrostis stolonifera L.) putting greens. Discriminant analysis identified 14 wavebands between 861 and 887 nm that distinguished drought severity. An overall accuracy of 85% was achieved using these wavebands with low‐stressed greens correctly classified 91%. High‐stressed greens were correctly classified 100% of the time with individual wavebands between 905 and 992 nm using 2003 data as a training model to cross‐validate 2004 data. These results suggest these individual wavebands are highly sensitive to early season drought‐stress in creeping bentgrass greens and could be considered a more stable portion of the spectrum over time concerning high‐stressed creeping bentgrass putting greens. A significant relationship (p = 0.034) was established between average reflectance values of wavebands between 1480 and 1530 nm and volumetric soil water content (VWC). Although not highly correlated, this relationship demonstrated that as VWC increased, reflectance decreased. Data collected in late spring/early summer may be the optimal time to detect areas of putting greens most susceptible to drought stress before unfavorable growth conditions occur.