Book review     

Thomas A. Jones  Sterling J. Helwick Jr.  T. R. Healy  Terrell W. Miller 《Mathematical Geology》1993,25(1):99-106

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Review: the environmental status and implications of the nitrate time lag in Europe and North America     

Sara E. Vero  Nandita B. Basu  Kimberly Van Meter  Karl G. Richards  Per-Erik Mellander  Mark G. Healy  Owen Fenton 《Hydrogeology Journal》2018,26(1):7-22

The efficacy of water quality policies aiming to reduce or prevent nitrate contamination of waterbodies may be constrained by the inherent delay or “time lag” of water and solute transport through unsaturated (soil) and saturated (groundwater) pathways. These delays must be quantified in order to establish realistic deadlines, thresholds and policy expectations, and to design effective best management practices. The objective of this review is to synthesise the current state of research on nitrate-related time lags in both the European and North American environmental and legislative contexts. The durations of time lags have been found to differ according to climatic, pedological, landscape and management scenarios. Elucidation of these driving factors at a watershed scale is essential where water quality is impaired or at risk. Finally, the existence of time lags is increasingly being acknowledged at a policy level and incorporated into the development of environmental legislation. However, the full impact of these time lags is not yet fully understood or appreciated, and continued outreach and education in scientific, public and policy venues is still required.  相似文献   

Traversing Fantasies,Activating Desires: Economic Geography,Activist Research,and Psychoanalytic Methodology     

Stephen Healy 《The Professional geographer》2013,65(4):496-506

In this article I recount the ways that key concepts in Lacanian psychoanalytic theory—the relationship between language and desire, fantasy and subject formation, ethics and the traversal of fantasy—have enabled a novel methodological approach to activist research. Psychoanalysis allows us to recast research as a process of encountering and traversing fantasies, which is simultaneously a process of engendering new representations, desires, subjectivities, and societies.  相似文献   

Debris dispersal modeling for the great Sumatra Tsunamis on Banda Aceh and surrounding waters     

Gegar Prasetya  Kerry Black  Willem de Lange  Jose Borrero  Terry Healy 《Natural Hazards》2012,60(3):1167-1188

The Great Sumatra Tsunami on 26 December 2004 generated large amounts of debris and waste throughout the affected coastal region in the Indian Ocean. In Banda Aceh—Indonesia, the tsunami flows were observed carrying a thick muddy sludge that mixed with all kinds of debris from the destroyed buildings, bridges and culverts, vehicles, fallen trees, and other flotsam. This waste and debris was mostly deposited inland, but traveled both onshore and offshore. Numerical dispersal modeling is carried out to simulate the transport of debris and waste produced by the tsunamis during the event. The model solves the Lagrangian form of the transport/dispersion equations using novel particle tracking techniques. Model results show that understanding the pathway and distribution of the suspended materials and flotsam caused by tsunamis is important for a proper hazards mitigation plan and waste management action, and to minimize serious long-term adverse environmental and natural resources consequences.  相似文献   

Assemblage structure,spatial patterns,recruitment, and post‐settlement mortality of subtidal bivalve molluscs in a large harbour in north‐eastern New Zealand     

R. G. Cole  P. J. Hull  T. R. Healy 《新西兰海洋与淡水研究杂志》2013,47(2):317-329

Infaunal bivalve molluscs on the flood tidal delta of Tauranga Harbour, north‐eastern New Zealand, were surveyed twice over a 6‐month period, with the aim of assessing shellfish resources, assessing the magnitudes of temporal and spatial variability in abundances, and identifying potentially important processes. The surveys identified a total of 31 bivalve taxa from 27 sites. Species richness per site ranged between 0 and 9, and varied greatly in space and time, as did two other measures of diversity. Extremely high densities of bivalves (>20 000 m^‐2) were encountered at several sites. Densities of several abundant species varied greatly in time, as a result of recruitment pulses. The abundances of the three species that dominated the fauna (Paphies australis, Tawera spissa, and Ruditapes largillierti) had characteristic spatial scales on the order of 200 m. Comparisons of size frequency distributions for individual sites suggested that mortality or emigration in the first year of benthic life was high. Substantial populations of bivalves occur on Centre Bank, and the most abundant of these are greatly influenced by events early in their lives.  相似文献   

Applications of parallel processing to astrodynamics     

S. Coffey  L. Healy  H. Neal 《Celestial Mechanics and Dynamical Astronomy》1996,66(1):61-70

Parallel processing is being used to improve the catalog of earth orbiting satellites and for problems associated with the catalog. Initial efforts centered around using SIMD parallel processors to perform debris conjunction analysis and satellite dynamics studies. More recently, the availability of cheap supercomputing processors and parallel processing software such as PVM have enabled the reutilization of existing astrodynamics software in distributed parallel processing environments, Computations once taking many days with traditional mainframes are now being performed in only a few hours. Efforts underway for the US Naval Space Command include conjunction prediction, uncorrelated target processing and a new space object catalog based on orbit determination and prediction with special perturbations methods.GRC International, Colorado Springs, currently located at Naval Laboratory  相似文献   

Interpolation of TC0₂ data on a 1° × 1° grid throughout the water column below 500 m depth in the Atlantic Ocean     

C. Goyet  R. Healy  S.J. McCue  D.M. Glover 《Deep Sea Research Part I: Oceanographic Research Papers》1997,44(12):1945-1955

We have combined the available total CO₂, temperature, salinity and oxygen data from the TTO, SAVE and WOCE programs in the Atlantic Ocean to parameterize TCO₂ below 500 m depth as a function of potential temperature, salinity and apparent oxygen utilization. We then use the Levitus data set of temperature, salinity and oxygen to compute the TCO₂ profiles at the resolution of the Levitus data set on a 1° × 1° grid with a vertical resolution of 33 layers, more densely spaced in the upper 1500 m than below. Depending on the method used to interpolate the data (along isopycnals or vertically by station), the estimated random uncertainty of the computed TC0₂ values in the Atlantic Ocean throughout the water column below the wintertime mixed layer depth ranges from ± 7.1 μmol kg⁻¹ to t 5.9 μmol kg⁻¹.  相似文献   

An investigation into the removal of oil from rock utilising magnetic particle technology     

Orbell JD  Dao HV  Kapadia J  Ngeh LN  Bigger SW  Healy M  Jessop R  Dann P 《Marine pollution bulletin》2007,54(12):1958-1961

The application of magnetic particle technology to environmental remediation has tended to focus, up to now, upon the removal of oil contamination from plumage and fur. The present research demonstrates the potential of this technology to remove oil contamination from the surface of rock. Specifically, a single treatment has been demonstrated to remove more than 80% by weight of heavy bunker oil from the surface of a common foreshore rock type. A further three treatments have been shown to result in an optimum removal of up to 94% by weight. The results are highly reproducible and offer the possibility of achieving up to 100% removal with the appropriate use of pre-conditioners.  相似文献   

Quantifying the sensitivity of simulated climate change to model configuration     

Barry H. Lynn  Richard Healy  Leonard M. Druyan 《Climatic change》2009,92(3-4):275-298

This study used “factor separation” to quantify the sensitivity of simulated present and future surface temperatures and precipitation to alternative regional climate model physics components. The method enables a quantitative isolation of the effects of using each physical component as well as the combined effect of two or more components. Simulation results are presented from eight versions of the Mesoscale Modeling System Version 5 (MM5), one-way nested within one version of the Goddard Institute for Space Studies Atmosphere-Ocean Global Climate Model (GISS AOGCM). The MM5 simulations were made at 108 km grid spacing over the continental United States for five summers in the 1990s and 2050s. Results show that the choice of cumulus convection parameterization is the most important “factor” in the simulation of contemporary surface summer temperatures and precipitation over both the western and eastern USA. The choice of boundary layer scheme and radiation package also increases the range of model simulation results. Moreover, the alternative configurations give quite different results for surface temperature and precipitation in the 2050s. For example, simulated 2050s surface temperatures by the scheme with the coolest 1990s surface temperatures are comparable to 1990s temperatures produced by other schemes. The study analyzes the spatial distribution of 1990s to 2050s projected changes in the surface temperature for the eight MM5 versions. The predicted surface temperature change at a given grid point, averaged over all eight model configurations, is generally about twice the standard deviation of the eight predicted changes, indicating relative consensus among the different model projections. Factor separation analysis indicates that the choice of cumulus parameterization is the most important modeling factor amongst the three tested contributing to the computed 1990s to 2050s surface temperature change, although enhanced warming over many areas is also attributable to synergistic effects of changing all three model components. Simulated ensemble mean precipitation changes, however, are very small and generally smaller than the inter-model standard deviations. The MM5 versions therefore offer little consensus regarding 1990s to 2050s changes in precipitation rates.  相似文献   

Contents of Volume 24     

W. P. De Lange  T. R. Healy 《Natural Hazards》2001,24(3):321-322

Table of Contents

Contents of Volume 24  相似文献