Visualization of three-dimensional datasets     

Ireland  Jack  Walsh  Robert W.  Galsgaard  Klaus 《Solar physics》1998,181(1):87-90

The effective visualization of three-dimensional (3d) datasets, both observationally and computationally derived, is an increasing problem in solar physics. We present here plots of computational data derived from the 3d reconstruction of the magnetic field of a loop system, rendered as anaglyphs. By combining images of the same 3d object from two slightly different angles a realistic and useful 3d effect is obtained, aiding data visualization. The application of the same technique to real solar data (such as from the Coronal Diagnostic Spectrometer (CDS) on board the Solar and Heliospheric Observatory (SOHO)) is discussed.  相似文献   

Book reviews     

César N. Caviedes  Emilio Biagini  H. -J. Kümpel  Jack D. Ives 《GeoJournal》1996,40(4):413-419

Under thhe drought conditions that have occurred in Bulgaria during the last decade, agricultural use of non-conventional water may be an important resource. This is a specific case of simultaneous purification and utilisation by soil ecological systems. However, using non-conventional quality water presents a number of ecological and health risks and poses problems connected with soil and surface and ground water contaminated and with producing crops of acceptable quality. Bulgaria's municipal, industrial, and rural wastewater reclamation and reuse, in addition to other non conventional water resources as sea water, drainage water and mineralised groundwater, may be a reliable source even in drought years and thus is capable of replacing potable used in agriculture. This paper reviews the work of the authors and their colleagues in assessing the irrigation potentials of waste water in Bulgaria.  相似文献   

Ferromanganese nodules from MANOP Sites H,S, and R—Control of mineralogical and chemical composition by multiple accretionary processes   总被引：3，自引：0，他引：3  

Jack Dymond  Mitchell Lyle  Bruce Finney  David Z. Piper  Kim Murphy  Roberta Conard  Nicklas Pisias 《Geochimica et cosmochimica acta》1984,48(5):931-949

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Modeling Volatile Chemical Transport, Biodecay, and Emission to Indoor Air     

Jack C. Parker 《Ground Water Monitoring & Remediation》2003,23(1):107-120

A model is presented for estimating vapor concentrations in buildings because of volatilization from soil contaminated by non- aqueous phase liquids (NAPL) or from dissolved contaminants in ground water. The model considers source depletion, diffusive- dispersive transport of the contaminant of concern (COC) and of oxygen and oxygen-limited COC biodecay. Diffusive-advective transport through foundations and vapor losses caused by foundation cross-flow are considered. Competitive oxygen use by various species is assumed to be proportional to the product of the average dissolved-phase species concentration and a biopreference factor. Laboratory and field data indicate the biopreference factor to be proportional to the organic carbon partition coefficient for the fuel hydrocarbons studied. Predicted indoor air concentrations were sensitive to soil type and subbase permeability. Lower concentrations were predicted for buildings with shallow foundations caused by flushing of contaminants by cross-flow. NAPL source depletion had a large impact on average exposure concentration. Barometric pumping had a minor effect on indoor air emissions for the conditions studied. Risk-based soil cleanup levels were much lower when biodecay was considered because of the existence of a threshold source concentration below which no emissions occur. Computed cleanup levels at NAPL-contaminated sites were strongly dependent on total petroleum hydrocarbon (TPH) content and COC soil concentration. The model was applied to two field sites with gasoline-contaminated ground water. Confidence limits of predicted indoor air concentrations spanned approximately two orders of magnitude considering uncertainty in model parameters. Measured contaminant concentrations in indoor air were within model-predicted confidence limits.  相似文献   

Variable near-surface deformation along the Commerce segment of the Commerce geophysical lineament, southeast Missouri to southern Illinois, USA     

Jack K. Odum  William J. Stephenson  Robert A. Williams 《Tectonophysics》2003,368(1-4):155

Recent studies have demonstrated a plausible link between surface and near-surface tectonic features and the vertical projection of the Commerce geophysical lineament (CGL). The CGL is a 5- to 10-km-wide zone of basement magnetic and gravity anomalies traceable for more than 600 km, extending from Arkansas through southeast Missouri and southern Illinois and into Indiana. Twelve kilometers of high-resolution seismic reflection data, collected at four sites along a 175-km segment of the CGL projection, are interpreted to show varying amounts of deformation involving Tertiary and some Quaternary sediments. Some of the locally anomalous geomorphic features in the northern Mississippi embayment region (i.e., paleoliquefaction features, anomalous directional changes in stream channels, and areas of linear bluff escarpments) overlying the CGL can be correlated with specific faults and/or narrow zones of deformed (faulted and folded) strata that are imaged on high-resolution seismic reflection data. There is an observable change in near-surface deformation style and complexity progressing from the southwest to the northeast along the trace of the CGL. The seismic reflection data collaborate mapping evidence which suggests that this region has undergone a complex history of deformation, some of which is documented to be as young as Quaternary, during multiple episodes of reactivation under varying stress fields. This work, along with that of other studies presented in this volume, points to the existence of at least one major crustal feature outside the currently defined zone of seismic activity (New Madrid Seismic Zone) that should be considered as a significant potential source zone for seismogenic activity within the midcontinent region of the United States.  相似文献   

The use of aquifer-media characteristics to model vulnerability to contamination,Manawatu region,New Zealand   总被引：1，自引：2，他引：1  

Gabor Bekesi  Jack McConchie 《Hydrogeology Journal》2002,10(2):322-331

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Book Reviews: Geology in South-West Scotland: an Excursion Guide Edited by P. Stone. British Geological Survey, 1996. No. of Pages: 214. Price: £10.     

Jack Treagus 《Geological Journal》1997,32(3):293-293

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The Mapping of Geological Structures by Ken McClay,Open University Press, 1988. No of pages: 168. Price: £7.95 (paperback).     

Jack Treagus 《Geological Journal》1989,24(3):235-236

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Quest for the origins of the first Americans. E. James Dixon, 1993, University of New Mexico Press,xvi + 154 pp., $24.95 (clothbound)     

Jack Donahue 《Geoarchaeology》1993,8(5):434-436

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Preserving Ground Water Samples With Hydrochloric Acid Does Not Result in the Formation of Chloroform     

Paul J. Squillace  James F. Pankow  Jack E. Barbash  Curtis V. Price  John S. Zogorski 《Ground Water Monitoring & Remediation》1999,19(1):67-74

Water samples collected for the determination of volatile organic compounds (VOCs) are often preserved with hydrochloric acid (HCl) to inhibit the biotransformation of the analytes of interest until the chemical analyses can he performed. However, it is theoretically possible that residual free chlorine in the HCl can react with dissolved organic carbon (DOC) to form chloroform via the haloform reaction. Analyses of 1501 ground water samples preserved with HCl from the U.S. Geological Survey's National Water-Quality Assessment Program indicate that chloroform was the most commonly detected VOC among 60 VOCs monitored. The DOC concentrations were not significantly larger in samples with detectable chloroform than in those with no delectable chloroform, nor was there any correlation between the concentrations of chloroform and DOC. Furthermore, chloroform was detected more frequently in shallow ground water in urban areas (28.5% of the wells sampled) than in agricultural areas (1.6% of the wells sampled), which indicates that its detection was more related to urban land-use activities than to sample acidification. These data provide strong evidence that acidification with HCl does not lead to the production of significant amounts of chloroform in ground water samples. To verify these results, an acidification study was designed to measure the concentrations of all trihalomethanes (THMs) that can form as a result of HCl preservation in ground water samples and to determine if ascorbic acid (C₆H₈O₆) could inhibit this reaction if it did occur. This study showed that no THMs were formed as a result of HCl acidification, and that ascorbic acid had no discernible effect on the concentrations of THMs measured.  相似文献