Single artificial wetland successfully treats different types of wastewater

The world's first full-scale artificial wetland designed to treat both sewage effluent and mine wastewater has been found to continuously remove high levels of pollutants, a recent study concludes. Treating both types of wastewater at the same time proved to be highly beneficial because they contain pollutants which are more easily removed when mixed together

Book Reviews

Urban Planning and Land Development Control Law. By Donald Hagman. This book seeks to distill, summarize and state textually the wisdom on planning and development control law collected and serves as a supplement to Mr. Hagman\u27s casebook. The reviewer criticizes the book for not more fully addressing zoning issues and the related problem of population concentration and dispersion as evidenced in the Golden v. Planning Board case. Public Workers and Public Unions. Edited by Sam Zagoria. This book brings together divergent views on on the growth of unions and other employee organizations, the impacts ad legal issues presented by collective bargaining, and the problems of the regulation of labor relations in the public sector

Three dimensional scattering center imaging techniques

Two methods to image scattering centers in 3-D are presented. The first method uses 2-D images generated from Inverse Synthetic Aperture Radar (ISAR) measurements taken by two vertically offset antennas. This technique is shown to provide accurate 3-D imaging capability which can be added to an existing ISAR measurement system, requiring only the addition of a second antenna. The second technique uses target impulse responses generated from wideband radar measurements from three slightly different offset antennas. This technique is shown to identify the dominant scattering centers on a target in nearly real time. The number of measurements required to image a target using this technique is very small relative to traditional imaging techniques

Wetland-based passive treatment systems for gold ore processing effluents containing residual cyanide, metals and nitrogen species

Gold extraction operations generate a variety of wastes requiring responsible disposal in compliance with current environmental regulations. During recent decades, increased emphasis has been placed on effluent control and treatment, in order to avoid the threat to the environment posed by toxic constituents. In many modern gold mining and ore processing operations, cyanide species are of most immediate concern. Given that natural degradation processes are known to reduce the toxicity of cyanide over time, trials have been made at laboratory and field scales into the feasibility of using wetland-based passive systems as low-cost and environmentally friendly methods for long-term treatment of leachates from closed gold mine tailing disposal facilities. Laboratory experiments on discrete aerobic and anaerobic treatment units supported the development of design parameters for the construction of a field-scale passive system at a gold mine site in northern Spain. An in situ pilot-scale wetland treatment system was designed, constructed and monitored over a nine-month period. Overall, the results suggest that compost-based constructed wetlands are capable of detoxifying cyanidation effluents, removing about 21.6% of dissolved cyanide and 98% of Cu, as well as nitrite and nitrate. Wetland-based passive systems can therefore be considered as a viable technology for removal of residual concentrations of cyanide from leachates emanating from closed gold mine tailing disposal facilities

Integral Glass Encapsulation for Solar Arrays

Work reported was performed during the period from August 1977 to December 1978. The program objective was to continue the development of electrostatic bonding (ESB) as an encapsulation technique for terrestrial cells. Economic analyses shows that this process can be a cost-effective method of producing reliable, long lifetime solar modules. When considered in sufficient volume, both material and equipment costs are competitive with conventional encapsulation systems. In addition, the possibility of integrating cell fabrication into the encapsulation process, as in the case of the preformed cell contacts discussed in this report, offers the potential of significant overall systems cost reduction

The Electoral Consequences of Neoliberal Reform Explaining Voter Turnout in Latin America\u27s Dual Transition Era

Voter turnout has declined precipitously during Latin America\u27s 25 year experience with representative democracy. This decline has occurred in conjunction with another important trend. Across the region, economic development directed by state leaders and characterized by heavy state intervention has been replaced by a development model, commonly referred to as the Washington Consensus, in which markets are the preferred instrument for growth and the state plays a minimal role. This means that as people were casting off their undemocratic past, their economies were also undergoing fundamental change. This simultaneous turn to democratic governments and marketbased economic policy is commonly called Latin America\u27s dual transition. The twin transition gives rise to the basic research question of this work: Is the dramatic decline in democratic participation throughout Latin America somehow linked to the political or economic consequences of market reform

Vortex-induced vibration of catenary riser: reduced-order modeling and lock-in analysis using wake oscillator

A new reduced-order model capable of analyzing the vortex-induced vibration of catenary riser in the ocean current has been developed. This semi analytical-numerical approach is versatile and allows for a significant reduction in computational effort for the analysis of fluid-riser interactions. The incoming current flow is assumed to be steady, uniform, unidirectional and perpendicular to the riser plane of initial equilibrium curvatures

Experimental Study of Isothermal Wake-Flow Characteristics of Various Flame-Holder Shapes

An investigation of the isothermal wake-flow characteristics of several flame-holder shapes was carried out in a 4- by 4-inch flow chamber. The effects of flame-holder-shape changes on the characteristics of the Karman vortices and thus on the recirculation zones to which experimenters have related the combustion process were obtained for several flame holders. The results may furnish a basis of correlation, of combustion efficiency and stability for similarly shaped flame holders in combustion studies. Values of the spacing ratio-(ratio of lateral spacing to longitudinal spacing of vortices] obtained for the various shapes approximated the theoretical value of 0.36 given by the Karman stability analysis. Variations in vortex strength of more than 200 percent and in frequency of more than 60 percent were accomplished by varying flame-holder shape. A maximum increase in the recirculation parameter of 56 percent over that for a conventional V-gutter was also obtained. Varying flameholder shape and size enables the designer to select many schedules of variations in vortex strength and frequency- not obtainable by changing size only and may make it possible to approach theoretical maximum vortex strength for any given frequency

Accounting for palaeoclimate and topography: a rigorous approach to correction of the British geothermal dataset

Raw heat flow measurements typically require correction for both palaeoclimate and topography if temperatures are to be reliably extrapolated to depths greater than those where temperature is measured. Such corrections are thus an essential step in quantifying geothermal energy resources. However, although both types of correction were pioneered decades ago by British workers, they have been omitted or underplayed in subsequent assessments of the UK geothermal dataset. Furthermore, as most UK heat flow measurements to date have utilised shallow boreholes, the magnitudes of the required corrections (for both effects) are exacerbated. In addition, the location of Britain, at a range of latitude with a temperate climate at present but where arctic conditions prevailed during much of the Pleistocene, means that the palaeoclimate correction, for a borehole of a given depth, is particularly large. Outside regions of high relief relative to borehole depth, palaeoclimate corrections at sites in Britain are indeed larger in magnitude than topographic corrections, and for almost all boreholes are additive. The magnitude of the palaeoclimate correction depends on assumptions about palaeotemperature anomalies and their durations, but from the available evidence it can be assessed, for a very shallow borehole in an unglaciated part of southern Britain with rocks of thermal conductivity 3 W m−1 °C−1, as 27 mW m−2. Air temperatures during Pleistocene cold stages decreased northward, but in much of northern Britain the Earth's surface was not exposed to these low temperatures for part of the Late Pleistocene due to the insulating effect of cover by ice sheets; the detailed correction for each locality thus depends on the local histories of air temperature anomalies and of ice cover, and may therefore potentially be greater or less than is typical for southern England. The past failure to recognise the magnitude of palaeoclimate corrections at sites in Britain, and to incorporate them into studies of geothermics, has led to systematic underestimation of temperatures at depth and, thus, of the overall geothermal energy resource