Marine Fishes in Fresh and Brackish Waters of Virginia Rivers

In the fresh and brackish waters of the James, Chickahominy, Pamunkey, Mattaponi and Rappahannock rivers in Virginia, 18 species of marine fishes ( exclusive of anadromous and catadromus forms) have been collected. Gunter\u27s (1942) exhaustive survey of the occurrence of Atlantic coast marine fishes in fresh water is here amplified for the most important tidal rivers of Virginia. Since 1949 intensive collecting has been done in brackish and tidal fresh waters of the Pamunkey and Rappahannock rivers, and numerous. collections have been made in the James, Chickahominy, and Mattaponi

Artificial Inhomogeneous Tapered Impedance Sheet Characterization and Applications

The ability to manipulate a complex impedance sheet about a PEC or general dielectric cylinder of arbitrary diameter to control the overall scattering characteristics at particular angles for shielding or scattering applications is presented. It is shown that with the capability to readily control both the real and imaginary components of a percolated lossy film\u27s effective impedance, specific impedance distributions can be obtained to effectively direct the overall nulls in the bistatic scattering pattern. The exact approach only requires negligible truncation error of the matrix solution and can be applied to cylinders of arbitrary size. This approach relies on general impedance sheet boundary conditions in addition to a Fourier series representation of the impedance sheet distribution, with the utilization of Wronskian and recurrence relations, to produce a computationally efficient matrix solution for the scattered field expansion coefficient an. This scattering coefficient an can then be included in the expression for a two-dimensional scattering width, allowing for the computation of scattering patterns of arbitrary diameter cylinder impedance sheet distributions. The ability to adapt sheet impedances to effectively control the overall nulls in the bistatic scattering pattern will be demonstrated, with practically-implemented impedance characteristics. Lastly, a novel rectangular X-band waveguide system will be utilized to characterize the electromagnetic properties of the Φ-dependent impedance sheet

Understanding the Influence of Turbulence in Imaging Fourier-Transform Spectrometry of Smokestack Plumes

An imaging Fourier-transform spectrometer (IFTS) was used to collect infrared hyper-spectral imagery of smokestack plume of a coal-burning power facility to assess the influence of turbulence on spectral retrieval of temperature (T) and pollutant concentrations (Ci). Radiance fluctuations due to plume turbulence introduced scene change artifacts (SCA) in the spectra. Time-averaging the spectra minimizes SCA magnitudes, but accurate T and Ci retrieval would require a priori knowledge of the statistical distribution of temperature and other stochastic flow field parameters. A method of quantile sorting in interferogram space that would allow the retrieval of the temperature distribution is presented and used to identify turbulence throughout the plume. Immediately above the stack exit, T and Ci estimates compared well to in situ measurements, and turbulence introduced only small systematic errors. Systematic errors, however, were more significant in other parts of the plume. While more complicated radiance fluctuations precluded retrieval of the temperature distribution, the results demonstrate the utility of additional information associated with interferogram quantiles and suggest the utility of IFTS in non-intrusive flow field analysis

Relative abundance of young fishes in Virginia estuaries

Watermen have expressed the opinion that commercial fish production varies considerably from one Virginia estuary to another. Preliminary surveys of the young fishes present in the various rivers have suggested that the relative abundance of young fishes also differs from river to river. The surface trawl (Massmann, Ladd, and McCutcheon, 1952) has been used to obtain quantitative information on the distribution and relative abundance of young fishes in five major Virginia estuaries

Lower James River pollution study, City Point to Chickahominy, August 6 - September 6, 1951 : a preliminary report of findings, conclusions and recommendations

Hopewell,m Virginia.is ·a highly industrialized city, the Celanese Corporation of .America, the Continental Can Company, the Hercules Powder Company and the Solvay Process: Division of· Allied Chemical and Dye Corporation having plants there. All of these plants have industrial and human wastes, the combined amount of which is great from. the standpoint of both volume and strength. In addition, there. are human wastes from the City cf Hopewell and its suburbs in Prince George County and from Camp Lee. All of those wastes, sewage and industrial are discharged into the James River, Bailey Creek and into other tributaries of the two. Primary treatment is given the wastes at Camp Lee; the others are discharged untreated. The location of all discharges in the Hopewell vicinity are shown in Figure I. With the exception of Bailey Creek, the impact of these wastes on the streams they enter was largely unknown, prior to this study. For many years Bailey Creek has been organized as an open sewer. Following passage of the Virginia. State Water Control -Law in 1946, the Hopewell industries all began programs leading to reduction of wastes they discharged. In order for them to determine the extent to which such reductions must ultimately be carried, it soon became apparent that information was needed regarding the effect of their wastes on the James River. During: the summer of 1951::the Hopowell industries, through the Hopewell Manufactures Association requested.the Water·Control Board\u27s help in making a study of the stream in the· Hopewell vicinity in an attempt to answer this question. The Board\u27s staff agreed to lend such assistance as was possible, and the initial phases of such a study were completed during the period ·August 6 - September 6, 1951