Protection Dams Research Articles

Hydrotechnical facilities within the Chernobyl nuclear power plant exclusion zone: impacts on hydrologic regime and plant growth patterns of floodplain water bodies of the Pripyat River

As result of the Chernobyl nuclear power plant accident the territory of the left-bank flood-lands of the Pripyat River have undergone intensive radionuclide contamination. With the purpose of preventing the washing away of radioactive substances, a complex of flood protection dams was constructed. This construction changed the hydrological regime of these territories and caused overgrowth by higher aquatic plants. Absence of a flowing mode of reservoirs, the stagnant phenomena during spring and seasonal high waters on the embank site have caused amplification of eutrophication processes, swamping and, connected with it, increase of water-marsh floristic complex in the structure of the vegetative cover.

Experiments on High-Speed Liquid Films Over Downward-Facing Wetting and Nonwetting Surfaces

ABSTRACTThe fusion event in inertial fusion energy reactors can damage the chamber first walls. The Prometheus design study used a high-speed tangentially injected thin film of molten lead to protect the upper endcap of the reactor chamber. To assure full chamber coverage, the film must remain attached. Film detachment due to gravitational effects is most likely to occur on downward-facing surfaces.Experiments were therefore conducted on turbulent water films with initial thicknessess and speeds up to 2 mm and 11 m/s, respectively, onto the downward-facing surface of a flat plate 0-45° below the horizontal. Average film detachment and lateral extent along the plate were measured. Detachment length appears to be a linear function of Froude number. Results for film flows over wetting and nonwetting surfaces show that surface wettability has a major impact. The data are used to establish conservative “design windows” for film detachment. Film flow around cylindrical obstacles, modeling protective dams around chamber penetrations, was also studied. The results suggest that cylindrical dams cannot be used to protect penetrations, and that new chamber penetration geometries that avoid flow separation are a major design issue for this type of thin liquid protection.

Macrophytes of the Exclusion Zone of the Chernobyl Nuclear Power Station: the Formation of Plant Communities and Peculiarities of Radioactive Contamination of the Left-Bank Floodplain of the Pripyat River

The construction of a complex of flood protective dams on the left bank of the floodplain of the Pripyat river was responsible for changes in the hydrological regime of its water bodies, and also in the character of thickets of higher aquatic plants. Results of the study of the content of 90Sr and 137Cs in higher aquatic plants made it possible to reveal the peculiarities of accumulation of radionuclides by various species of macrophytes, and also to distinguish those species of macrophytes which can be used as indicators of radioactive contamination. The peculiarities of accumulation of radionuclides by various species of higher aquatic plants can essentially influence their contribution to the total content of radionuclides.

Anambe Agricultural Development Project, Senegal

The Anambe project represents a practical case of an agricultural and rural development project. It comprises all stages of development from the sectoral studies and investigations up to technical and economic feasibility, followed by final design, preparation of tender documents, tendering procedures, awarding of contracts and supervision of construction including the establishment of a pilot farmThe main purpose of the Anambe project is to provide for irrigation of about 16, 000 ha of land (mainly double cropping of rice), most of it presently being rainfed or uncultivatedThe project includes two storage dams with one featuring a small hydroelectric power plant of 5500 kW, one flood protection dam, two pumping stations and the provision of an irrigation and drainage network which will enable an area of 16'000 ha to be irrigated. Irrigation by flooding has been chosen for the rice fields, and furrow irrigation for the other crops. The project, boasting an average annual production of 88, 000 tons of rice and 9000 tons of maize and sorghum contributes to the stabilization of fcjod crop production in the Casamance

I Some hydraulic models and analogues for solving spatial lateral and bottom seepage through earth dams II Privileged way and its significance for stability of protective dams and levees

I Some hydraulic models and analogues for solving spatial lateral and bottom seepage through earth dams II Privileged way and its significance for stability of protective dams and levees

A New York State Fern Law

For the past two years, with much preceding discussion, the Syracuse Botanical Club has been working on the problem of legal action to save at least one of the rare ferns, menaced by commercialism and auto-recreationists, for which our section is famous. Green Lake, east of Jamesville, was dowered by nature with a fern flora that made it a magnet for scientists and fern lovers the world over. Though the work of the Solvay Process Co., to which the fern-clad cliffs were only raw material for baking soda, this rare and beautiful station has been utterly destroyed. Rarest of all was the hart's tongue fern, Scolopendrium, and some four or five hundred specimens of this were removed, with belated assistance from the Solvay Co., from certain destruction to a location nearby that we hope will be safe. The hart's tongue is found only in four or five spots in Onondaga and Madison counties, in Tennessee, in Ontario, and apparently in Guatemala, and in no other locality on this continent. Its appearance is so unlike the ordinary aspect of a fern that the average person might overlook it. The chief danger of extinction, aside from the destruction of its habitats, comes from students of botany who exchange plants, and from nurserymen who dig it up to sell. The members of the Syracuse Botanical Club feel that they have at last done something practical by way of protection in getting the new amendment, protecting the hart's tongue, passed by the legislature. Miss L. W. Roberts, and other active members, but chiefly Mrs. John W. Church, Chairman of the Club Legislation Committee, have worked like beavers to build the protective dam. Assemblyman Horace M. Stone, aided by Assemblyman 115