An Air Quality Data Analysis System for Interrelating Effects,Standards, and Needed Source Reductions: Part 8. An Effective Mean O3 Crop Reduction Mathematical Model

A plant injury mathematical model, applied previously to acute and chronic leaf injury data, is used here to model National Crop Loss Assessment Network (NCLAN) data for 15 cultivars and to calculate species parameters from the cultivar analyses. Percent crop yield reduction is estimated as a function of a new parameter, the effective mean O₃ concentration: m_e = [(Σ c_h ^?1/v)/n]^?v, where c_h is the hourly average ambient O₃ concentration for each daytime hour (defined here as 9:00 A.M.–4:00 P.M., always standard time) of data available at an air sampling site for summer (defined here as June 1–August 31), n is the total number of such available hours, and v is an exposure time-concentration parameter, calculated here to be approximately –0.376. Crop yield reduction for soybean is calculated here as z = 0.478 In (tm_e ^2-66) – 0.42, where z is the Gaussian transform of percent crop reduction, t is the hours of exposure (525 h is used here; 7 h/day for 75 days), and In indicates that the natural logarithm is taken of the quantity within parentheses. Crop yield reductions for seven plant species are estimated with similar equations for each of the 1824 site-years of 1981–1983 hourly O₃ concentration data available in the National Aerometric Data Bank (NADB). County-average effective mean O₃ concentrations are indicated by shading on a U.S. map. State-average O₃ parameters and estimated percent crop yield reductions are tabulated. The National Ambient Air Quality Standard (NAAQS) for O₃ specifies that, on the average, the second highest daily maximum 1-h average O₃ concentration in a year shall not exceed 0.12 ppm. For years 1981-1983,71% of the NADB sites recorded annual second highest daily maximum 1-h average O3 concentrations below 0.125 ppm (for summer daytime hours). Ambient O₃ concentrations reduced the total U.S. crop yield an estimated 5% for years 1981–1983. (Summer, daytime, and all acronyms are always used herein as defined above.)     

Issues and Trends in Electrostatic Precipitation Technology for U.S. Utilities

The pace and direction of electrostatic precipitator (ESP) technology evolution in the United States will be governed by two key forces. The first is new clean air legislation passed by the U.S. Congress and signed by President Bush on November 15,1990. This law requires electric utilities to further reduce SO₂ and NO_x emissions, which may impact particulate controls. In addition, very fine (< 10 micron) participates and potentially toxic trace emissions from utility power plants may be regulated. The second major factor is the expected upsurge in new plant construction beginning in the late 1990s. Together, these forces should define the performance requirements and market for new ESPs.

This paper identifies and briefly describes technologies that the Electric Power Research Institute (EPRI) is developing to help U.S. utilities meet these challenges cost-effectively. Among the technologies addressed are: advanced digital voltage controls, flue gas conditioning, intermittent energization, temperature-controlledprecharging (i.e., two-stage ESP), wide plate spacing, positive energization of corona electrodes for hot-side ESPs, and integration of conventional ESPs with pulse-jet baghouses.     

An Air Quality Data Analysis System for Interrelating Effects,Standards, and Needed Source Reductions: Part 10. Potential Ambient O3 Standards to Limit Soybean Crop Reduction

Soybean percent crop reduction was estimated as a function of ambient O₃ concentrations for each of 80 agricultural sites in the National Aerometric Data Bank (NADB) for each available year of data for years 1981-1985. Fourteen O₃ concentration statistics were calculated for each of the resulting 320 site-years of data. The two statistics that correlated best with estimated crop reduction were an effective mean O₃ concentration (1 percent of variance unexplained) and an arithmetic mean O₃ concentration (4 percent unexplained). The worst correlation of the 14 was for the statistic used in the present O₃ National Ambient Air Quality Standard (NAAQS), the second highest daily maximum 1-h O₃ concentration (42 percent unexplained). The number of site-years for estimated percent soybean yield reductions was plotted versus increasing O₃ concentrations for each of the 14 O₃ statistics. A maximum crop reduction line was drawn on each plot. These lines were used to estimate (and list) potential ambient O₃ standards for each of the 14 statistics that would limit soybean crop reduction at agricultural. NADB sites to 5, 10, 15, or 20 percent.     

Advances In Out Door Lysimeter Techniques

Different methods exist for measuring soil water and solute fluxes in and below the root zone and have been critically reviewed. Besides indirect methods (e.g. water balance, tensiometer, time domain reflectometry – TDR, frequency domain reflectometry – FDR, environmental tracer) direct methods (e.g. drainage-type lysimeter, water fluxmeter) have a long tradition and have been successfully used in seepage research. A large weighable out door lysimeter is the best method for obtaining reliable data about seepage water quantity and quality, but it involves significant investment and additional expenses for maintenance. To tackle this problem new methods for the vertical collection of large volume soil monoliths (up to 6 m³) as well as for the horizontal collection (up to 6 m³) have been developed. For the placement of the lysimeter a container lysimeter unit was constructed, which is cheaper than a conventional steel or concrete cellar. Furthermore, the technical design of the newly developed lysimeter types as a weighable gravitation lysimeter, a weighable groundwater lysimeter and a lateral flow lysimeter are presented.     

Growth of two Antarctic lamellibranchs: Adamussium colbecki and Laternula elliptica

The growth of two Antarctic lamellibranchs, Adamussium colbecki (E.A. Smith) and Laternula elliptica (King and Broderip), has been investigated. A. colbecki is a pectinid that grows to a shell height of approximately 70 mm in 6 to 7 years; L. elliptica is a deep-burrowing form, ecologically similar to the genus Mya and grows to a shell length of approximately 90 mm in 12 to 13 years. The growth pattern of both species is accurately described by the Bertalanffy growth equation and both have smaller values of the Bertalanffy K coefficient than comparable temperate species (A. colbecki K=0.24, L. elliptica K=0.16).     

THE IMPACT OF HIGHWAY CONSTRUCTION ON A NORTH FLORIDA WATERSHED1

ABSTRACT A 20 month study of some effects of highway construction on water quality was conducted during construction of Interstate 10 at Tallahassee, Florida. Highway construction resulted in significant increases in turbidity, suspended solids, total phosphorus, and dissolved silicon in downstream waters despite use of recommended procedures for erosion control. Highway construction did not result in significant increases in dissolved phosphorus or nitrogen.     

Political influence on non-cooperative international climate policy

We analyze non-cooperative international climate policy in a setting of political competition by national interest groups. In the first stage, countries decide whether to link their domestic emission permit markets to an international market, which only forms if it is supported by all countries. In the second stage, countries non-cooperatively decide on the number of tradable emission allowances. In both stages, special interest groups try to sway the government in their favor. We find that (i) both the choice of regime and the levels of domestic and global emissions only depend on the aggregate levels of organized stakes in all countries and not on their distribution among individual interest groups and (ii) an increase in lobbying influence by a particular lobby group may backfire by inducing a change towards the lobby group's less preferred regime.