Questions and Answers for Environmental Professionals     

Daniel J. Gibby  Ralph E. Moon 《Ground Water Monitoring & Remediation》1997,17(2):56-58

  相似文献   

Spatial variation in delaware bay (U.S.A.) marsh creek fish assemblages     

Kenneth W. Able  David M. Nemerson  Ralph Bush  Phillip Light 《Estuaries and Coasts》2001,24(3):441-452

Delaware Bay is one of the largest estuaries on the U.S. eastern seaboard and is flanked by some of the most extensive salt marshes found in the northeastern U.S. While physicochemical and biotic gradients are known to occur along the long axis of the bay, no studies to date have investigated how the fish assemblage found in salt marsh creeks vary along this axis. The marshes of the lower portion of the bay, with higher salinity, are dominated bySpartina spp., while the marshes of the upper portion, with lower salinity, are currently composed primarily of common reed,Phragmites australis, S. alterniflora, or combinations of both. Extensive daytime sampling (n=815 tows) during May–November 1996 was conducted with otter trawls (4.9 m, 6 mm mesh) in six intertidal and subtidal marsh creek systems (upper and lower portions of each creek) where creek channel depths ranged from 1.4–2.8 m at high tide. The fish taxa of the marsh creeks was composed of 40 species that were dominated by demersal and pelagic forms including sciaenids (5 species), percichthyids (2), and clupeids (7), many of which are transients that spawn outside the bay but the early life history stages are abundant within the bay. The most abundant species wereMorone americana (24.3% of the total catch),Cynoscion regalis (15.4%),Micropogonias undulatus (15.3%),Anchoa mitchilli (12.0%), andTrinectes maculatus (10.8%). Non-metric Multi-Dimensional Scaling ordination of catch per unit effort (CPUE) data indicated two fish assemblages that were largely independent of the two major vegetation types, but generally corresponded with spatial variation in salinity. This relationship was more complex because some of the species for which we could discriminate different age classes by size had different patterns of distribution along the salinity gradient.  相似文献   

Computers In Geography     

Ralph E. Olson 《The Professional geographer》1970,22(3):161-161

  相似文献   

Spectral analysis in geophysics,M. Bath,Developments in Solid Earth Geophysics, 7, Elsevier,Amsterdam (1974), p. 563, U.S. $46.20     

Ralph A. Wiggins 《Earth》1976,12(1):79-80

  相似文献   

The 1970 Public Use Sample: A Geographical Context     

Ralph A. Sanders 《The Professional geographer》1975,27(3):347-350

  相似文献   

Design principles for individual transferable quotas     

Ralph E. Townsend  James McColl  Michael D. Young 《Marine Policy》2006

Individual transferable quota (ITQ) institutions should be designed to minimize two types of transaction costs. First, to minimize the costs of transferring ITQ rights among rights-holders and users, rights should be separated into three components: a permanent entitlement share, an annual catch allocation, and a license to fish. Second, ITQ rights can reduce the transactions costs for development of self-governance by owners both by specifying a non-unanimous voting rule (preferably one-share/one-vote) and also by delineating clear standards for devolution of responsibility from government. These same two principles for reduction of transactions costs can be applied, with slight variation, to individual transferable input systems.  相似文献   

Resource economies and neoliberal experimentation: the reform of industry and community in rural British Columbia   总被引：1，自引：0，他引：1  

Nathan Young  Ralph Matthews 《Area》2007,39(2):176-185

This paper argues that the current literature on neoliberalism in advanced capitalist societies has concentrated primarily on urban issues, and has thus failed to see resource economies and regions as theoretically significant sites of neoliberal reform. Using research from British Columbia, Canada, we argue that resource regions are often targets of intense neoliberal experimentation. The neoliberal project in British Columbia involves an extreme shift in state policy from a strong Fordist-Keynesian programme to recent efforts to 'liberate' corporate actors from non-market social and spatial obligations (to environment, labour and community). We argue that such policy shifts have exceptional consequences in resource regions due to strong and direct state influence in corporate-resource and community-level economies. We draw several theoretical lessons from this research for the mainstream literature on neoliberal reform.  相似文献   

Comparison of Wind-tunnel and Water-channel Simulations of Plume Dispersion through a Large Array of Obstacles with a Scaled Field Experiment     

Eugene Yee  Ralph M. Gailis  Alexander Hill  Trevor Hilderman  Darwin Kiel 《Boundary-Layer Meteorology》2006,121(3):389-432

We report on measurements of the near-field dispersion of contaminant plumes in a large array of building-like obstacles at three scales; namely, at full-scale in a field experiment, at 1:50 scale in a wind-tunnel simulation, and at 1:205 scale in a water-channel simulation. Plume concentration statistics extracted from the physical modelling in the wind-tunnel and water-channel simulations are compared to those obtained from a field experiment. The modification of the detailed structure of the plume as it interacts with the obstacles is investigated. To this purpose, measurements of the evolution of the mean concentration, concentration fluctuation intensity, concentration probability density function, and integral time scale of concentration fluctuations in the array plume obtained from the field experiment and the scaled wind-tunnel and water-channel experiments are reported and compared, as well as measurements of upwind and within-array velocity spectra. Generally, the wind-tunnel and water-channel results on the modification of the detailed plume structure by the obstacles were qualitatively similar to those observed in the field experiments. However, with the appropriate scaling, the water-channel simulations were able to reproduce quantitatively the results of the full-scale field experiments better than the wind-tunnel simulations.  相似文献   

On the Origin of Near-Surface Streaks in the Neutrally-Stratified Planetary Boundary Layer     

Philippe Drobinski  Ralph C. Foster 《Boundary-Layer Meteorology》2003,108(2):247-256

The dynamics of near-surface streak formation in the neutrallystratified, rotating planetary boundary layer areinvestigated. The purpose of this note is to compare large-eddysimulation results to theoretical predictions suggesting thatstreaks are associated with non-normal mode optimal perturbations.Streaks are regions near the surface of alternating high and lowspeed fluid organized into nearly linear bands, with horizontalspacing of several hundred metres, oriented up to 30° relativeto the geostrophic wind, that evolve through a continuous cycle ofgeneration, growth, decay and reformation. We find that the earlystages of streak formation and growth are consistent with thelinear theory.  相似文献   

Thermalized Newtonian Bose Stars     

Heinz Dehnen  Ralph N. Gensheimer 《Astrophysics and Space Science》1998,259(4):355-369

We consider star models consisting of spin 0 particles interacting only gravitationally, e.g. Higgs-particles as possible dark matter objects. The particle gas of finite temperature is treated according to the Bose-Einstein-statistics in its non- relativistic limit; then the use of Newtonian gravity is sufficient too. The limits of these restrictions are estimated. The local temperature is determined with the use of energy conservation. The mass-radius relation of the objects and their further behaviours as Bose-Einstein-condensation in the outer regions are calculated. We find strong similarities with the features of white dwarfs and neutron stars. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献