Physical Sciences and Mathematics Commons^™

Trace-Element Concentrations In Streambed Sediment Across The Conterminous United States, Karen Rice

United States Geological Survey: Staff Publications

Trace-element concentrations in 541 streambed-sediment samples collected from 20 study areas across the conterminous United States were examined as part of the National Water-Quality Assessment Program of the U.S. Geological Survey. Sediment samples were sieved and the <63-μm fraction was retained for determination of total concentrations of trace elements. Aluminum, iron, titanium, and organic carbon were weakly or not at all correlated with the nine trace elements examined: arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, and zinc. Four different methods of accounting for background/ baseline concentrations were examined; however, normalization was not required because field sieving removed most of the background differences between samples. The sum of concentrations of trace elements characteristic of urban settings-copper, mercury, lead, and zinc-was well correlated with population density, nationwide. Median concentrations of seven trace elements (all nine examined except arsenic and selenium) were enriched in samples collected from urban settings relative to agricultural or forested settings. Forty-nine percent of the sites sampled in urban settings had concentrations of one or more trace elements that exceeded levels at which adverse biological effects could occur in aquatic biota.

Atrazine Degradation In A Small Stream In Iowa, Dana W. Kolpin, Stephen J. Kalkhoff

United States Geological Survey: Staff Publications

A study was conducted during 1990 through an 11.2-km reach of Roberts Creek in northeastern Iowa to determine the fate of atrazine in a surface water environment. Water samples were collected at ~1-month intervals from April through November during stable low to medium flow conditions and analyzed for atrazine and two of its initial biotic degradation products, desethylatrazine and deisopropylatrazine. Samples were collected on the basis of a Lagrangian model of streamflow in order to sample the same parcel of water as it moved downstream. Atrazine concentrations substantially decreased (roughly 25-60% ) between water entering and exiting the study reach …

Late Quaternary Loess In Northeastern Colorado: Part Ii—Pb Isotopic Evidence For The Variability Of Loess Sources, John N. Aleinikoff, Daniel R. Muhs, Rebecca R. Sauer, C. Mark Fanning

United States Geological Survey: Staff Publications

A new application of the Pb isotopic tracer technique has been used to determine the relative importance of different silt sources for late Wisconsin loess in the central Great Plains of eastern Colorado. Samples of the Peoria Loess collected throughout the study area contain K-feldspar derived from two isotopically and genetically distinct sources: (1) glaciogenic material from Early and Middle Proterozoic crystalline rocks of the Colorado province, and (2) volcaniclastic material from the Tertiary White River Group exposed on the northern Great Plains. Pb isotopic compositions of K-feldspar in loess from two dated vertical sections (at Beecher Island and Last …

Comparison Of An Enzyme-Linked Immunosorbent Assay (Elisa) To Gas Chromatography (Gc) - Measurement Of Polychlorinated Biphenyls (Pcbs) In Selected Us Fish Extracts, James L. Zajicek, Donald E. Tillitt, Ted R. Schwartz, Christopher J. Schmitt, Robert O. Harrison

United States Geological Survey: Staff Publications

The analysis of PCBs in fish tissues by immunoassay methods was evaluated using fish collected from a US monitoring program, the National Contaminant Biomonitoring Program of the US Department of Interior, Fish and Wildlife Service. Selected composite whole fish samples, which represented widely varying concentrations and sources of PCBs, were extracted and subjected to congener PCB analysis by gas chromatography (GC) and total PCB analysis using an ELISA (ePCBs) calibrated against technical Aroclor 1248. PCB congener patterns in these fishes were different from the patterns found in commercial Aroclors or their combinations as demonstrated by principal component analysis of normalized …

Abrupt Along-Strike Change In Tectonic Style: San Andreas Fault Zone, San Francisco Peninsula, Mary Lou Zoback, Robert C. Jachens, Jean A. Olson

United States Geological Survey: Staff Publications

Seismicity and high-resolution aeromagnetic data are used to define an abrupt change from compressional to extensional tectonism within a 10- to 15-km-wide zone along the San Andreas fault on the San Francisco Peninsula and offshore from the Golden Gate. This 100-km-long section of the San Andreas fault includes the hypocenter of the M_w= 7.8 1906 San Francisco earthquake as well as the highest level of persistent microseismicity along that ~470-km-long rupture. We define two distinct zones of deformation along this stretch of the fault using well-constrained relocations of all post- 1969 earthquakes based a joint one-dimensional velocity/hypocenter inversion …

200,000 Years Of Climate Change Recorded In Eolian Sediments Of The High Plains Of Eastern Colorado And Western Nebraska, Daniel R. Muhs, James Swinehart, David Loope, John N. Aleinikoff, Josh Been

United States Geological Survey: Staff Publications

Loess and eolian sand cover vast areas of the western Great Plains of Nebraska, Kansas and Colorado (Fig. 1). In recent studies of Quaternary climate change, there has been a renewed interest in loess and eolian sand. Much of the attention now given to loess stems from new studies of long loess sequences that contain detailed records of Quaternary glacial-interglacial cycles, thought to be a terrestrial equivalent to the foraminiferal oxygen isotope record in deep-sea sediments (Fig. 2). Loess is also a direct record of atmospheric circulation, and identification of loess paleowinds in the geologic record can test atmospheric general …

A Memorial For William V. Sliter, Robert G. Douglas, Jere H. Lipps, James C. Ingle Jr., John Barron

United States Geological Survey: Staff Publications

William V. (Bill) Sliter, an internationally known micropaleontologist and research geologist for the U.S. Geological Survey, passed away suddenly, October, 1997, while talking to a colleague in his office. In his honor, B. Huber, T. Bralower, and M. Leckie organized a keynote symposium ‘‘Paleoecological and Geochemical Signatures of Cretaceous Anoxic Events’’ at the 1998 annual meeting of the Geological Society of America in Toronto, Canada. This theme issue of the Journal of Foraminiferal Research contains the published papers from the symposium and is dedicated to his memory.

Biogenic Silica Records From The Bdp93 Drill Site And Adjacent Areas Of The Selenga Delta, Lake Baikal, Siberia, Steven M. Colman, John A. Peck, Josephine Hatton, Eugene B. Karabanov, John W. King

United States Geological Survey: Staff Publications

Biogenic silica contents of sediments on the lower Selenga Delta and Buguldeika saddle in Lake Baikal show distinct fluctuations that reflect changes in diatom productivity, and ultimately, climate. The pattern of the upper 50 m of the section, dating from about 334 ka, is similar to that of the marine oxygen isotope record, increasingly so as the younger sediments become progressively finer grained and less locally derived with time. The last two interglaciations are marked by biogenic silica abundances similar to those of the Holocene. The equivalent of marine oxygenisotope stage 3 is distinctly intermediate in character between full glacial …

Kentucky Water Resources Research Institute Annual Technical Report Fy 1998, Kentucky Water Resources Research Institute, University Of Kentucky

KWRRI Annual Technical Reports (USGS’s 104b Grant Program)

This document consolidates the reporting requirements of the base grant and regional competitive grant awards in a single technical report which includes: 1) a synopsis of each ongoing research project and of each research project completed during the period, 2) a list of reports published, 3) a brief description of information transfer activities, 4) a summary of student support during the reporting period, and 5) notable achievements and awards during the year.

The He-Lih Potential Energy Surface Revisited. I. An Interpolated Rigid Rotor Surface, Robert Hinde

Chemistry Publications and Other Works

We reconsider the potential energy surface of the He–LiH system recently examined by Gianturco and co-workers [F. A. Gianturco et al., Chem. Phys. 215, 227 (1997)]. We compute the He–LiH interaction energy at the CCSD(T) level using large correlation consistent atomic basis sets supplemented with bond functions. To capture the severe anisotropy of the He–LiH potential, we interpolate our ab initio points in the angular direction with cubic splines, then expand the splines in terms of Legendre polynomials. The resulting smooth potential surface differs substantially from that of Gianturco et al.; in particular, our attractive He–LiH well is more …

Management Of Software Engineering, The - Part I: Principles Of Software Engineering, Harlan D. Mills

The Harlan D. Mills Collection

Software engineering may be defined as the systematic design and development of software products and the management of the software process. The general principles of software engineering are set forth in Part I, in which the author relates software engineering to the whole field of the system development process--system engineering, hardware engineering, software engineering, and system integration. Presented briefly are overviews of the major aspects of software engineering--design, development, and management.

1999 File Geodatabase Containing Photo Point Locations, Aerial Photos, And Flight Maps, City Of Tampa Department Of Sanitary Sewers Bay Study Group, Pete Reehling, Richard Mckenzie

Data Sets

The Bay Study Group was created by the City of Tampa in 1976 to monitor the effects of pollution abatement that occurred in Hillsborough Bay when the city’s wastewater treatment plant was upgraded from primary to advanced treatment in 1979. The Bay Study Group documented a remarkable restoration of water quality parameters and biological indicators in Hillsborough Bay from the mid 1980s until 2009, when it was disbanded. This zip Geodatabase file contains the photo point locations, aerial photos, and flight maps for the year 1999.

Soliton Stability In A Z (2) Field Theory, J. J. P. Veerman, D. Bazeia, Fernando Moraes

Mathematics and Statistics Faculty Publications and Presentations

We investigate the stability of the coupled soliton solutions of a two-component Z(2) vector fieldmodel, in contraposition to similar solutions of a Z(2)×Z(2)model recently introduced. We demonstrate that the coupled soliton solutions of the Z(2) model are classically unstable.

Search For Supersymmetry With A Dominant R-Parity Violating Lqd̄ Coupling In E+E- Collisions At Centre-Of-Mass Energies Of 130 Gev To 172 Gev, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

A search for pair-production of supersymmetric particles under the assumption that R-parity is violated via a dominant LQD¯LQD¯ coupling has been performed using the data collected by ALEPH at centre-of-mass energies of 130–172 GeV. The observed candidate events in the data are in agreement with the Standard Model expectation. This result is translated into lower limits on the masses of charginos, neutralinos, sleptons, sneutrinos and squarks. For instance, for m0=500m0=500 GeV/c2/c2 and tanβ=2–√tan⁡β=2 charginos with masses smaller than 81 GeV/c2/c2 and neutralinos with masses smaller than 29 GeV/c2/c2 are excluded at the 95% confidence level for any generation structure of …

Making Sharing Pervasive: Ubiquitous Computing For Shared Note Taking, James A. Landay, Richard C. Davis

Research Collection School Of Computing and Information Systems

As a variety of low-cost note-taking devices becomes pervasive, shared notes can help work groups better communicate ideas and information. To explore this idea further, we carried out three related case studies of how members of a large research group shared meeting notes. The group found value in combining personal notes and presentation slides with a single, unifying document, such as regular meeting minutes. The minutes provided structure when there were too many sources of notes. We used this insight in our design of NotePals, a note-sharing system with a lightweight process, an interface, and hardware that distinguish it from …

Bounds On A Bug, Arthur T. Benjamin, Matthew T. Fluet '99

All HMC Faculty Publications and Research

In the game of Cootie, players race to construct a "cootie bug" by rolling a die to collect component parts. Each cootie bug is composed of a body, a head, two eyes, one nose, two antennae, and six legs. Players must first acquire the body of the bug by rolling a 1. Next, they must roll a 2 to add the head to the body. Once the body and head are both in place, the remaining body parts can be obtained in any order by rolling two 3s for the eyes, one 4 for the nose, two 5s for the …

On The Number Of Radially Symmetric Solutions To Dirichlet Problems With Jumping Nonlinearities Of Superlinear Order, Alfonso Castro, Hendrik J. Kuiper

All HMC Faculty Publications and Research

This paper is concerned with the multiplicity of radially symmetric solutions u(x) to the Dirichlet problem

Δu+f(u)=h(x)+cφ(x)

on the unit ball Ω⊂R^N with boundary condition u=0 on ∂Ω. Here φ(x) is a positive function and f(u) is a function that is superlinear (but of subcritical growth) for large positive u, while for large negative u we have that f'(u)<μ, where μ is the smallest positive eigenvalue for Δψ+μψ=0 in Ω with ψ=0 on ∂Ω. It is shown that, given any integer k≥0, the value c may be chosen so large that there are 2k+1 solutions with k or less interior nodes. Existence of positive solutions is excluded for large enough values of c.

Model Updating By Adding Known Masses And Stiffnesses, Philip D. Cha, Lisette G. De Pillis

All HMC Faculty Publications and Research

New approaches are developed to update the analytical mass and stiffness matrices of a system. By adding known masses to the structure of interest, measuring the modes of vibration of this mass-modified system, and finally using this set of new data in conjunction with the initial modal survey, the mass matrix of the structure can be corrected. A similar approach can also be used to update the stiffness matrix of the system by attaching known stiffnesses. Manipulating the mass and stiffness correction matrices into vector forms, the connectivity information can be enforced, thereby preserving the physical configuration of the system, …

An Inverse Function Theorem, Alfonso Castro, J. W. Neuberger

All HMC Faculty Publications and Research

In this note we present a local surjectivity result which is applicable to differential equations for which full boundary conditions may not be known. Our method uses continuous steepest descent and Sobolev gradients.

Black Holes And The Sym Phase Diagram, Miao Li, Emil Martinec, Vatche Sahakian

All HMC Faculty Publications and Research

Making combined use of the matrix and Maldacena conjectures, the relation between various thermodynamic transitions in super Yang-Mills (SYM) theory and supergravity is clarified. The thermodynamic phase diagram of an object in DLCQ M theory in four and five non-compact space dimensions is constructed; matrix strings, matrix black holes, and black p-branes are among the various phases. Critical manifolds are characterized by the principles of correspondence and longitudinal localization, and a triple point is identified. The microscopic dynamics of the matrix string near two of the transitions is studied; we identify a signature of black hole formation from SYM physics.

A Theoretical Study Of The Electronic Coupling Element For Electron Transfer In Water, Newt E. Miller '99, Matthew C. Wander '97, Robert J. Cave

All HMC Faculty Publications and Research

The electronic coupling element for electron transfer between a donor and acceptor in water is examined using simulations combining molecular dynamics and semiempirical quantum mechanics. In the first phase of the simulations a model donor and acceptor are solvated in water, using realistic potentials. Following equilbration, molecular dynamics simulations are performed with the donor, acceptor, and water at approximately 300 K, under periodic boundary conditions. In the second phase of the simulation, the electronic coupling element between the donor and acceptor is calculated for a number of time slices, in the presence of the intervening water molecules (those having a …

The Bordalo Order On A Commutative Ring, Melvin Henriksen, Frank A. Smith

All HMC Faculty Publications and Research

If R is a commutative ring with identity and ≤ is defined by letting a ≤ b mean ab = a or a = b, then (R,≤) is a partially ordered ring. Necessary and sufficient conditions on R are given for (R,≤) to be a lattice, and conditions are given for it to be modular or distributive. The results are applied to the rings Z_n of integers mod n for n ≥ 2. In particular, if R is reduced, then (R,≤) is a lattice iff R is a weak Baer ring, and (R,≤) is a distributive lattice iff R …

Observation And Application Of Optical Interference And Diffraction Effects In Reflection From Photochemically Fabricated Gaussian Interfaces, Lynne Koker, Kurt W. Kolasinski

Chemistry Faculty Publications

No abstract provided.

Procedure For Raising Trout In The Classroom As Part Of Environmental Education, Ronn Chapman

Theses Digitization Project

No abstract provided.

A Lower Bound For The Cyclic Cutwidth Of The N-Cube, James Shigeo Namekata

Theses Digitization Project

No abstract provided.

Neural Computation Of All Eigenpairs Of A Matrix With Real Eigenvalues, Serafim Theodore Perlepes

Theses Digitization Project

No abstract provided.

Mercury Contamination From Hydraulic Placer-Gold Mining In The Dutch Flat Mining District, California, Michael P. Hunerlach, James J. Rytuba, Charles N. Alpers

United States Geological Survey: Publications

Mercury contamination at historic gold mining sites represents a potential risk to human health and the environment. Elemental mercury (quicksilver) was used extensively for the recovery of gold at both placer and hardrock mines throughout the western United States. In placer mine operations, loss of mercury during gold recovery was reported to be as high as 30 percent. In the Dutch Flat mining district located in the Sierra Nevada region of California, placer mines processed more than 100,000,000 cubic yards of gold-bearing gravel. The placer ore was washed through mercury-charged ground sluices and drainage tunnels from 1857 to about 1900, …

Areas Susceptible To Irrigation-Induced Selenium Contamination Of Water And Biota In The Western United States, Ralph L. Seiler, Joseph P. Skorupa, Lorri A. Peltz

United States Geological Survey: Publications

The U.S. Department of the Interior (DOI) studied contamination induced by irrigation drainage in 26 areas of the Western United States during 1986–95. Comprehensive compilation, synthesis, and evaluation of the data resulting from these studies were initiated by DOI in 1992. Soils and ground water in irrigated areas of the West can contain high concentrations of selenium because of (1) residual selenium from the soil’s parent rock beneath irrigated land; (2) selenium derived from rocks in mountains upland from irrigated land by erosion and transport along local drainages, and (3) selenium brought into the area in surface water imported for …

Evaluation Of Special Sensor Microwave / Imager Sea-Ice Products, Kim Partington, Cheryl Bertoia

United States Department of Commerce: Staff Publications

Existing SSM/I algorithms are imperfect at mapping total and partial ice concentrations. This paper reviews recent findings based on comparisons of sea-ice products against other satellite data and U.S. National Ice Center (NIC) ice charts.

Characterisation And Optimisation Of Gypsum Crystallization, Catherine H. Shannon

Theses

Gypsum is produced as a by-product during the citric acid production process at ADM Ringaskiddy. The particle size and filterability of the gypsum has a critical bearing on the overall citric acid production rate. Prior to August 1996, research in the area of gypsum crystal optimisation at ADM had concentrated on the application of vortex mixing to perform the gypsum formation reaction. While the gypsum crystals produced with vortex mixing were found to be desirably clear of microcrystalline gypsum, the crystals were considerably smaller and more difficult to filter and wash. This research project sought to retain the advantages conferred …