bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Methods for Determining the Vertical Distribution of Hydraulic Conductivity
Authors: Taylor Kendrick , Wheatcraft Stephen , Hess John , Hayworth Joel , Molz Fred 
Published: August 2005

ABSTRACTSix borehole methods for determining the vertical distribution of hydraulic conductivity in unconsolidated geologic formations are evaluated. Straddle packer tests are inappropriate if there is a hydraulic path around the packer on the outside of the well screen. Methods based on grain‐size analysis fail to incorporate the influence of small‐scale structure and packing. Methods based on relationships between electrical and hydraulic conductivity require special conditions and are site‐ and formation‐specific. Borehole effects invalidate methods based on the natural flow of fluid through a well bore. Stoneley wave attenuation methods are not effective in unconsolidated formations. A single‐well electrical tracer test is effective, but requires the injection of significant volumes of fluid.
Investigation by DC Resistivity Methods of a Ground‐Water Barrier Beneath the San Bernardino Valley, Southern California
Authors: Park Stephen K. , Lambert Douglas W. , Lee Tien‐Chang 
Published: August 2005

AbstractDC resistivity methods were used to confirm the existence of the Bryn Mawr fault and to evaluate its efficacy as a barrier to ground water in the Bunker Hill basin beneath the San Bernardino valley, California. Vertical electrical sounding indicates layering and vertical offsets across the fault. Dipole‐dipole measurements located the fault and determined its attitude. Our modeling indicates that the fault gouge has decreasing resistivity with depth. The resistivity trend is likely caused by increasing clay content. If the interpretation is correct, the ability of the fault to impede ground‐water flow will increase with declining water levels. This theory is supported by greater offset of water levels across the fault when the levels were deeper. DC resistivity methods independently yield models which are consistent with known hydrogeological conditions, and can be used to predict them.
Aquifer Parameters from a One‐Dimensional Steady‐Leaky Type Curve
Authors: Motz Louis H. 
Published: August 2005

AbstractA drain function and type curve were defined for the one‐dimensional steady‐state leaky aquifer case, and a match‐point procedure was developed for determining the aquifer parameters of transmissivity and leakance. Values for these parameters can be determined by plotting steady‐state values of drawdown versus distance and matching the distance‐drawdown data to the steady‐leaky type curve. The procedure is illustrated by an example that utilizes field data from a canal pumping test in the Tampa, Florida area. Values of transmissivity = 164,000 ft2/day and leakance = 4.9 X 10‐3 day‐1 were determined for the Upper Floridan aquifer from distance‐drawdown and canal flowrate data. These values compare favorably with values of transmissivity and leakance determined from pumping tests and a digital model study in the same area.
Estimating the Precision of Ground‐Water Elevation Data
Authors: Gibbons Robert D. 
Published: August 2005

1. AbstractA common problem in ground‐water monitoring and hydrogeology in general is determining the precision with which to plot ground‐water elevation contours. If ground water represented a completely static system and could be measured without error, the choice would simply be a function of the ambition of the graphic artist or the capabilities of the available computer algorithm. Since contour maps involve an interpolation from a set of irregularly spaced points (i.e., wells or piezometers) to a grid or mesh of evenly spaced points, which in general contains far more points or “nodes” than the original dataset, virtually any level of “graphical precision” is possible (e.g., one‐tenth of a foot). However, ground‐water elevation measurements represent the results of a dynamic process that, in general, does not affect all wells equally. Furthermore, as in any measuring process in which humans are involved, errors of measurement must certainly exist. The natural consequence, of course, is that one component of the total variation in ground‐water elevation data represents random sampling fluctuations. The magnitude of these random sampling fluctuations can in turn be used to make probabilistic statements regarding the precision of ground‐water elevation data such that ground‐water elevation contours may be determined at meaningful intervals.The importance of empirically determining ground‐water elevation precision is that it assures us that the plotting interval will never be less than the precision of the generating ground‐water elevation data. Without this assurance, which of course is the typical case in practice, structure and even gradients that are observed in a contour plot may be nothing more than the effects of random sampling variability.
A Study of Acid Mine Drainage Using Earth Resistivity Measurements
Authors: Ebraheem A. M. , Hamburger M. W. , Bayless E. R. , Krothe N. C. 
Published: August 2005

AbstractA resistivity survey was conducted in a reclaimed mine spoils disposal site near Wheatland, Indiana to study the ground‐water contamination. Due to the high conductivity of the acidic leachate from coal refuse, it was possible to detect the valleys in which this material was dumped (gob valleys) by using the horizontal resistivity profiling technique. The thickness of the gob valleys and information about the stratigraphy of the site were obtained by using the vertical electrical sounding (VES) technique. The VES data for sounding points located near monitoring wells, together with the chemical analyses of water samples taken from these wells, were used to obtain an empirical relationship between the inferred earth resistivity and the amount of Total Dissolved Solids (TDS) in the ground water. The horizontal resistivity profiling data and the VES data at a 30‐ft electrode spacing were contoured. The resulting isoresistivity map, together with the empirical relationship, can be used to predict the approximate TDS concentration at a depth of approximately 30 ft at any point on the Wheatland site.
Survey of Microbial Populations in Buried‐Valley Aquifer Sediments from Northeastern Kansas
Authors: Sinclair James L. , Randtke Stephen J. , Denne Jane E. , Hathaway Lawrence R. , Ghiorse William C. 
Published: August 2005

AbstractTwenty‐two aseptically collected sediment core samples were obtained from below the water table (60 to 280 feet deep) at four pristine sites along a major buried‐valley aquifer system in northeastern Kansas. Samples were examined for total numbers of bacteria, viable aerobic bacteria, protozoa, and fungi. Contiguous samples were obtained in some transition zones of sediment texture or color in order to detect possible population shifts over small vertical distances related to changes in sediment characteristics. Total counts of bacteria varied between 106 and 108 per gram of dry sediment. Viable bacterial counts varied between 0 and 108 colony forming units per gram, usually being higher in sandy or gravelly sediments than in silty or clayey sediments. The relationship between sediment texture and microbial population density was confirmed statistically. Total numbers of bacteria correlated highly with variations in sediment sand and clay content. The population densities of viable bacteria and protozoa correlated moderately with these indicators of sediment texture. In some samples, populations of viable bacteria approached the total count of bacteria and the diversity of bacterial colony types appraoched that found in surface soil. Protozoa were found at low population densities in the coarser textured samples. The protozoa were similar to types commonly encountered in surface soil. No actinomycetes, fungi, or algae were detected in any samples.
Estimation of Leak Rates from Underground Storage Tanks
Authors: Levy Benjamin S. , Riordan Peter J. , Schreiber Robert P. 
Published: August 2005

AbstractA methodology for estimating the rate and volume of leakage from an underground storage tank (UST) is presented; by estimating leak rate and volume, the leak duration may be calculated. This is accomplished by measuring liquid hydrocarbon thickness upon the water table at two or more monitoring wells located at differing distances from the leaking UST. The methodology is based on Hantush (1967, 1968) and uses type‐curve fitting. Two solutions are developed: one for the case of a flat, rigid water table, and another for the case of a deflected water table. These solutions provide upper and lower estimates for leak rate and duration. The use of the technique is demonstrated by its application to a field case. The technique is best applied to sites with medium‐ to coarse‐grained sands and gravels with minimal capillary effects; application of the technique to sites of fine‐grained porous media may produce unreasonable results.
Causes of Soil Salinization: 1. A Basin in Southern Alberta, Canada
Authors: Hendry M. J. , Buckland G. D. 
Published: August 2005

AbstractThe cause of soil Salinization affecting 1700 ha of a basin in southern Alberta, Canada was examined. Water‐table data indicate that ground water recharges over a large diffuse area to the south of the salinized lands. Hydraulic‐head and hydraulic‐conductivity data and stream‐function modeling show that the recharging ground water travels laterally towards the salinized area in shallow, permeable beds of the Foremost Formation. The presence of an angular unconformity between the shallow, flat‐lying bedrock and the overlying Quaternary deposits causes the ground water to discharge at the salinized area. Calculated discharge rate to the salinized area ranges from 2 to 40 mm/yr.
The Role of Pumping Tests in Site Characterization: Some Theoretical Considerations
Authors: Butler James J. 
Published: August 2005

AbstractPumping tests are the primary means of estimating the large‐scale storage and transmissive properties of an aquifer for site‐characterization investigations. Most analyses of pumping‐induced drawdown are performed using either the Theis log‐log curve‐matching procedure or the approximate Cooper‐Jacob semilog method. These two procedures provide dissimilar estimates in nonuniform aquifers due to their emphasis on properties in different portions of a unit. The log‐log curve‐matching approach heavily weights the properties of local material, while the semilog procedure emphasizes the properties of material within the front of the cone of depression. The different emphasis of the two procedures results in log‐log parameters being more appropriate for estimating pumping‐well drawdown, while semilog parameters are better for estimating well yield. The magnitude of the difference between parameters estimated by the two approaches is a function of the degree of aquifer nonuniformity and the distance between the observation and pumping wells. The further the observation well is from the pumping well, the smaller the difference between the parameters. The difference between parameters estimated by slug tests and those estimated by pumping tests, on the other hand, will increase with this distance. Due to their emphasis on near‐well materials, slug‐test parameters may be of use in estimating pumping‐well drawdown when employed in a patchy aquifer model. In general, predictions of aquifer behavior can be improved by more careful application of the conventional techniques used in pumping‐test analyses.
Ground‐Water Contamination by High‐Density Immiscible Hydrocarbon Slugs in Gravity‐Driven Gravel Aquifers
Authors: Corapcioglu M. Yavuz , Hossain M. Akhter 
Published: August 2005

AbstractIn contrast to light hydrocarbons like gasoline that float on the water table, high‐density chlorinated hydrocarbons such as TCE and TCA released to the environment sink into the aquifer and remain at the bottom for extended periods of time. The migration of these hydrocarbons is generally governed by the vertical component instead of lateral transport as for low‐density hydrocarbons. The Buckley‐Leverett approach is extended to a two‐dimensional case to simulate the migration of a high‐density hydrocarbon displacing ground water in a highly pervious gravity‐driven natural‐gradient gravel aquifer. Governing equations are solved by modifying the USGS solute transport model (Konikow and Bredehoeft, 1978). The modification incorporates the fractional flow curves of water and their saturation derivatives in vertical and horizontal directions as functions of degree of water saturation. As an example, a contamination incident representing a TCE spill from a storage tank buried in the saturated zone is considered. Numerical results show that high‐density, low‐viscosity immiscible chlorinated hydrocarbons can travel deeper and further in contrast to lower‐density, higher‐viscosity compounds, and that the migration is dominated by gravity‐driven vertical flow until the plume reaches the lower boundary.
Quantitative Analysis for the Cleanup of Hydrocarbon‐Contaminated Soils by In‐Situ Soil Venting
Authors: Johnson Paul C. , Kemblowski Marian W. , Colthart James D. 
Published: August 2005

AbstractThe efficiency of any soil venting operation will depend significantly on three factors: vapor flowrate, vapor flow path relative to the contaminant distribution, and composition of the contaminant. Simple mathematical models were developed to be used as screening tools to help determine if soil venting will be a viable remediation option at any given spill site. The models relate the applied vacuum, soil permeability, and spill composition to the vapor flowrates, velocities, mass removal rates, and residual composition changes with time. In this report the screening models and some sample calculations are presented. The results illustrate the advantages and limitations of venting as a remediation tool, under both ideal and nonideal conditions.
Two Approaches to Design of Monitoring Networks
Authors: Spruill Timothy B. , Candela Lucila 
Published: August 2005

AbstractTwo different approaches to the design of a ground‐water‐quality monitoring network may be appropriate, depending on the type of information desired. First, where the objective is to determine what ground‐water‐quality characteristics are like in an area (statistical quantification of typical concentrations, as given by the mean or median, or percentage of wells exceeding various use standards), networks can be designed to provide estimates of known reliability using standard parametric and nonparametric statistical techniques. This approach can provide information adequate to perform general water‐quality assessments where the intention of the monitoring network is to provide data about general suitability of the water for various uses. Second, where the objective is to maximize areal ground‐water‐quality information, networks also can be designed using geostatistical techniques, such as kriging. This second approach would be appropriate when information is needed on where particular problem areas may exist.Both approaches were applied to 1965 chloride data from a deep confined aquifer in the Llobregat delta near Barcelona, Spain. Traditional statistical techniques are demonstrated to design a network that would provide an estimated median chloride concentration. A method is introduced that can be used to determine the sample size necessary to describe any selected quantile with known precision. On the basis of 120 observations in the 1965 data set, between 13 and 25 wells would be necessary to estimate the median chloride concentration within 40 percent of the true median with 95‐percent confidence. Kriging, a geostatistical technique, was applied to the data set to determine the minimum number of wells necessary to include in the network to retain the essential spatial information of the original network. By use of this technique, the original network of 120 wells was reduced by 17.5 percent to 99 wells, while the standard error was increased by only 1 percent.A comparison of these two approaches indicates that a network designed by use of geostatistical techniques generally will require larger sample sizes than networks designed by use of traditional techniques, but the geostatistical techniques can provide data adequate to describe both stochastic and spatial features of water‐quality variables. Detailed description of spatial variability requires many sample points for extremely variable data. On the basis of results presented in this paper, prediction errors for chloride concentrations in ground water at selected points in the Llobregat delta were as much as 300 percent. Nevertheless, even the modified network of 99 wells would produce statistical estimates adequate for most general water‐quality assessments, in addition to retaining the spatial information contained in the original 1965 data set.
Identification of Genes of VSH-1, a Prophage-Like Gene Transfer Agent of
Brachyspira hyodysenteriae
Authors: Matson Eric G. , Thompson M. Greg , Humphrey Samuel B. , Zuerner Richard L. , Stanton Thad B. 
Published: August 2005

ABSTRACT

VSH-1 is a mitomycin C-inducible prophage of the anaerobic spirochete
Brachyspira hyodysenteriae
. Purified VSH-1 virions are noninfectious, contain random 7.5-kb fragments of the bacterial genome, and mediate generalized transduction of
B. hyodysenteriae
cells. In order to identify and sequence genes of this novel gene transfer agent (GTA), proteins associated either with VSH-1 capsids or with tails were purified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The N-terminal amino acid sequences of 11 proteins were determined. Degenerate PCR primers were designed from the amino acid sequences and used to amplify several VSH-1 genes from
B. hyodysenteriae
strain B204 DNA. A λ clone library of
B. hyodysenteriae
B204 DNA was subsequently screened by Southern hybridization methods and used to identify and sequence overlapping DNA inserts containing additional VSH-1 genes. VSH-1 genes spanned 16.3 kb of the
B. hyodysenteriae
chromosome and were flanked by bacterial genes. VSH-1 identified genes and unidentified, intervening open reading frames were consecutively organized in head (seven genes), tail (seven genes), and lysis (four genes) clusters in the same transcriptional direction. Putative lysis genes encoding endolysin (Lys) and holin proteins were identified from sequence and structural similarities of their translated protein products with GenBank bacteriophage proteins. Recombinant Lys protein hydrolyzed peptidoglycan purified from
B. hyodysenteriae
cells. The identified VSH-1 genes exceed the DNA capacity of VSH-1 virions and do not encode traditional bacteriophage early functions involved in DNA replication. These genome properties explain the noninfectious nature of VSH-1 virions and further confirm its resemblance to known prophage-like, GTAs of other bacterial species, such as the GTA from
Rhodobacter capsulatus
. The identification of VSH-1 genes will enable analysis of the regulation of this GTA and should facilitate investigations of VSH-1-like prophages from other
Brachyspira
species.
APPROXIMATION OF THE STOCHASTIC RAYLEIGH–BÉNARD PROBLEM NEAR THE ONSET OF CONVECTION AND RELATED PROBLEMS
Authors: BLÖMKER DIRK 
Published: August 2005

It is well known that complicated stochastic evolution systems near a change of stability are often dominated by slow modes. We rigorously approximate the evolution of the system by stochastic ordinary differential equations describing the amplitudes of the dominating modes on a slow time-scale.In this paper we focus on equations with quadratic nonlinearity and give applications to the Rayleigh–Bénard problem and a model from surface growth perturbed by fractional noise.The unique existence of global solutions is not necessary.
Desmond Morris's Two Spheres
Authors: Root-Bernstein Robert 
Published: August 2005

What is the value of artistic practices, techniques, inventions, aesthetics and knowledge for the working scientist? What is the value of scientific practices, techniques, inventions, aesthetics and knowledge for the artist? When does art become science and science, art? Can an individual excel at both science and art, or is even a passing familiarity with one sufficient to influence the other significantly? Guest editor Robert Root-Bernstein continues the exploration of such questions in the second installment of the Leonardo special project “ArtScience: The Essential Connection.” Interested authors: please send proposals, queries and/or manuscripts to the Leonardo Editorial Office: < isast@leonardo.info >. Additional information available on the Leonardo web site: < www.leonardo.info >.
Dimitrios Doukas and the Accentuation of the New Testament Text of the Complutensian Polyglot
Authors: Lee John 
Published: August 2005

AbstractThis paper begins by pointing out the previously unobserved fact that the accentuation of the Greek New Testament text of the Complutensian Polyglot (1514) follows a monotonic system almost exactly the same as that now in use in Modern Greek. Next is considered the information on the matter in the preface to the volume. The Greek text of the preface is presented with English translation and notes. A number of misconceptions are dealt with. The question of the identity of the inventor of the accentuation is then explored in full. The evidence in favour of Dimitrios Doukas as editor of the text and author of the preface is summarised and augmented. The paper then argues that it was he who conceived and applied the system of accentuation. Possible other sources of the idea are considered and eliminated. Finally the question of who might have been behind the initial intention to print an unaccented text is discussed.
Virgin Territory: Purity and Divine Knowledge in Late Medieval Catoptromantic Texts[1] Le territoire vierge: Pureté et savoir divin dans les textes catoptromantiques du Moyen Âge tardif
Authors: Fanger Claire 
Published: August 2005

Abstract La catoptromancie (divination par l'observation d'objets brillants) est une pratique abondamment attestée dans l'histoire, depuis l'Antiquité. Toutefois, les travaux académiques consacrés aux rituels de catoptromancie médiévaux sont encore assez rares. Cet article traite d'abord des prières et des rituels catoptromantiques pratiqués à l'aide d'un médium—toujours un enfant vierge—, lesquels se trouvent, notamment, dans deux manuels de nécromancie mediévale (Bodleian Library, University of Oxford, Rawl. D. 252, et le manuel publié par Richard Kieckhefer sous le titre Forbidden Rites). Après une analyse de l'idée de virginité, qui apparaît dans les mots des prières, l'article se concentre sur l'explication qu'un philosophe du XIIIe siècle, Guillaume d'Auvergne, fournit en matière d'utilisation d'enfants vierges au cours d'expériences catoptromantiques. Guillaume s'emploie longuement à réfuter la doctrine platonicienne selon laquelle la science n'est qu'une sorte de réminiscence; mais malgré son opposition à l'idée de “science-réminiscence”, il se montre naturellement favorable à la notion, également platonicienne, selon laquelle la pureté virginale peut, en principe, donner plus facilement accès aux régions de lumière appartenant à l'ordre du Créateur. Selon Guillaume, la lumière divine habite tout naturellement l'âme qui n'est pas encombrée et accablée de vices corporels; toutefois, il est pratiquement impossible à l'âme seule, sans l'assistance de Dieu, de franchir les frontières de ces régions. Ici, Guillaume fait allusion aux expériences d'ascèse infructueuses, auxquelles il s'est lui-même livré dans son adolescence. Bien évidemment, malgré l'opposition théologique à l'encontre de l'expérience théurgique, il existe une intéressante continuité entre la pratique et la théorie de la catoptromancie médiévale. En conclusion, l'article fait brièvement état de quelques autres continuités entre, d'une part, les formes de théurgie médiévale (notamment, dans les prières de l'ars notoria et dans celles de Jean de Morigny); et d'autre part, les conversations de John Dee avec les anges. Enfin, l'auteur présente une suggestion peut-être susceptible de résoudre “l'énigme Edward Kelly”.