Agricultural and Urban Pollution

I have modified the scope of this paper slightly to include urban pollution because the pollution problems produced by the agricultural industry are essentially the same as those produced by municipalities. We know that environmental degradation occurs as a result of the discharge and the byproducts from both sources. In the case of agricultural activities, the terrain has and still is being modified to convert it to crop production. In the livestock industry, large populations of animals are being concentrated into relatively small areas to meet the economic pressures of meat production. With the human population, the numbers of people are not only increasing but are also concentrating. Probably more important, countless square miles of terrain have been denuded and modified to make way for highway and street construction or for the development of housing units. From both sources the results are the same. We have increased siltation; we have increased organic loading; and we have increased nutrient loadinghttps://scholarworks.wm.edu/vimsbooks/1030/thumbnail.jp

Nearshore Bottom Currents off Virginia Beach, Virginia

The Virginia Institute of Marine Science instituted a study of the nearshore currents in the Atlantic Ocean off Virginia Beach, Virginia in December 1967 under Contract No. NAOSU P-68-1595 and continued under Contract DACW-65-69-C-0019 _through March 1970. The program was designed to determine the\u27net current patterns in the area and attempted to determine the physical parameters responsible. The net current patterns determined could then be utilized to determine the fate of dredge spoil material discharged from hopper dredges at a disposal site located in the vicinity of latitude 36 ° 48\u27, longitude 75° 54\u27, ·or 3 nautical miles offshore

Heavy metals tolerance limits : terminal progress report

The toxicity of .metal ions Lo fresh-water organisms has received considerable attention but little is known regarding their effects on estuarine and marine forms. These studies were initiated to aid in the evaluation of marine pollution problems

Nutrient assimilation in a Virginia tidal system

Over-enrichment leading to environmental degradation and the production of aquatic nuisance conditions have destroyed the multi-use potential of several coastal tidal systems in the United States. The Middle and South Atlantic and the Gulf Coast drainage basins are especially vulnerable to this type of destruction because of their hydraulic characteristics. Many are drowned pre-Pleistocene river valleys having a large basin capacity relative to the fresh-water inflow. This results in a horizontal-boundary type estuary characterized by higher salinities on the left side (looking downstream) and the absence of a sharp salinity gradient from surface to bottom of the water column . The surface waters have a net downstream movement and the bottom waters have a net upstream movement with a theoretical level of no net motion near mid -depth. The time of passage or net non -tidal movement in t he fresh -water tidal section is almost directly related to the inflow rate at the most downstream physical barrier and to the basin capacity.https://scholarworks.wm.edu/vimsbooks/1186/thumbnail.jp

Biological and chemical study of Virginia\u27s estuaries

The field program of the chemical and biological investigation of Virginia\u27s three main estuarine systems--the James, York and Rappahannock rivers--was completed during this period. Eighteen regular cruises plus daily special cruises involving three vessels were made following the passage of Hurricane Camille. The final months of the period were utilized for the analyses of sediment samples and for data reduction

An Exactly Solvable Model of Generalized Spin Ladder

A detailed study of an $S={1\over2}$ spin ladder model is given. The ladder consists of plaquettes formed by nearest neighbor rungs with all possible SU(2)-invariant interactions. For properly chosen coupling constants, the model is shown to be integrable in the sense that the quantum Yang-Baxter equation holds and one has an infinite number of conserved quantities. The R-matrix and L-operator associated with the model Hamiltonian are given in a limiting case. It is shown that after a simple transformation, the model can be solved via a Bethe ansatz. The phase diagram of the ground state is exactly derived using the Bethe ansatz equation

Seasonal Occurrence of Epifauna on Test Panels In Hampton Roads, Virginia

A two-year study was made on settling patterns of some marine epifaunal frmcrtebrales in the port of Hampton Roads, Virginia. Asbestos fiber test panels, submerged to a depth of 5 m from a pier at the Norfolk Navy Base, wf:re used as substrates. The fouling assemblage consisted of species characteristic of the temperate North American Atlantic coast. Over half of the 41 species identified were either coelenterates or arthropods, although sponges, tttrbellarians, ectoprocts, J\u3eolychaetes, mollusks, and ascidians were present as well. Four species, Aselomaris michaeli, Clytia edwardsi, Obelia bicuspidata and 0. commissuralis, all hydroids, represent new distributional records for Virginia. The large annual range of water temperature results in distinct seasonal patterns of settlement. Attachment was heaviest froni May to November and lightest fi·om January to March. Barnacles (Balanus improvisus) were prevalent during spring and autumn, while ascidians (Molgula manhattensis, Botryllus schlosseri) and serpulids (Hydroides hexagona) were predominant in summer. Only Balanus improvisus occurred on the panels throughout the year

The ugly faces of pollution

Pt. 1. [no title] pt. 2. Toxic wastes pt. 3. Oxygen-removing wastes pt. 5. Over-enrichment pt. 5. Other pollutants

Phase diagram of an exactly solvable t-J ladder model

We study a system of one-dimensional t-J models coupled to a ladder system. A special choice of the interaction between neighbouring rungs leads to an integrable model with supersymmetry, which is broken by the presence of rung interactions. We analyze the spectrum of low-lying excitations and ground state phase diagram at zero temperature.Comment: LaTeX, 8 pp. incl. 1 figur