Physical Sciences and Mathematics Commons^™

Double Ionization Of Helium And Neon For Fast Heavy-Ion Impact: Correlated Motion Of Electrons From Bound To Continuum States, R. Moshammer, J. Ullrich, H. Kollmus, W. Schmitt, M. Unverzagt, O. Jagutzki, V. Mergel, H. Schmidt-Böcking, R. Mann, C. J. Woods, Ronald E. Olson

Physics Faculty Research & Creative Works

Double ionization of He and Ne by charged particle impact was explored in kinematically complete experiments measuring the final momenta of the two emerging electrons(Pfe1, Pfe2) and of the recoiling target ion PRf. The momentum transfer from the 3.6 MeV/u Se28+projectile to the electrons is found to be negligibly small. Thus distinct patterns observed in the Pfe1- versus - Pfe2spectra sensitively reflect the details of the electrons' correlated motion. Classical calculations reasonably describe the data only when the (e-e)interaction during the ionization reaction is included. © 1996 The American Physical Society.

Neutron Diffraction And Magnetic Studies Of Nd₂Fe₁₇₋ₓtₓ (T=Si, Mn) Alloys, William B. Yelon, Z. Hu, Mingxing Chen, H. Luo, F. Pourarian, Peter C. Ezekwenna, G. K. Marasinghe, K. H. J. Buschow, D. P. Middleton, William Joseph James

Physics Faculty Research & Creative Works

We have carried out neutron and magnetic studies on Nd₂Fe_17-xT_x (T=Si, Mn) alloys. the unit cell of the compounds contracts with both Si and Mn substitution. Si atoms avoid the 6c site, prefer the 18h site strongly, fill the 9d site steadily and fill the 18f site only at relatively high Si concentration. Mn atoms avoid the 9d sites but prefer the 6c site strongly, while the 18f site and 18h site fill slowly. the Si site occupancies appear to be dominated by the crystal environment while the Mn site occupancies are dominated by steric …

Measurements Of Recoil And Projectile Momentum Distributions For 19-Mev [Formula Presented] + Ne Collisions, V. Frohne, S. Cheng, R. M. Ali, M. L.A. Raphaelian, C. L. Cocke, Ronald E. Olson

Physics Faculty Research & Creative Works

The collision system of 19-MeV [Formula Presented] on Ne has been studied using recoil and projectile momentum spectroscopy. For each event, identified by final recoil and projectile charge state, the three-dimensional momentum vector of the recoil ion and the transverse momentum vector of the projectile ion were measured. The transverse momenta of the recoil and projectile ions were found to be equal in magnitude and opposite in direction, indicating that the transverse momentum exchange is dominated by interactions between the two ion cores. The transverse momentum distributions are well described by nCTMC calculations. The longitudinal momentum distributions of the recoil …

Donald J. Montgomery, Sitaram Jaswal, John Hardy, Paul M. Parker

John R. Hardy Papers

Donald J. Montgomery, long a research professor at Michigan State University, died suddenly from a stroke on 19 January at the age of 78.

Remote Ergonomic Research In Space: Spacelab Findings And A Proposal, Stewart I. Donaldson, Harvey Wichman

CGU Faculty Publications and Research

This paper discusses ergonomics research using remotely situated video camerasin spacecraft. Two prototype studies of crewmembers working in the micro-G environments aboard the first two flights of Spacelab are described. Various aspects of crew restraint, stabilization, manipulation of controls, and mobilization were observed, operationally defined, and quantified by observing videotaped scenes of Spacelab crewmembers. In the first study, four performance behaviors were quantified to provide estimates of their frequency of occurrence and variation over the course of each of the flights. The behaviors and their mean percent of observed times were: Hand-Hold 32.2%, Foot Restraint 35.3%, Translation 9.4%, and Struggle …

Cover - Table Of Contents

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

The Natural History Of Aconitum Noveboracense Gray (Northern Monkshood), A Federally Threatened Species, Margaret A. Kuchenreuther

Journal of the Iowa Academy of Science: JIAS

Aconitum noveboracense Gray (Ranunculaceae), commonly known as northern monkshood, is a federally threatened herbaceous perennial that occurs in disjunct populations in Iowa, Wisconsin, Ohio and New York. It appears to be a glacial relict, existing today only in unique areas with cool, moist microenvironments, such as algific talus slopes. Field studies reveal that A. noveboracense has a complex life history. Perennation of individual plants occurs through the annual production of daughter tubers. Vegetative reproduction is commonly observed, and can occur by means of aerial and subterranean bulbils, as well as by development of adventitious root buds. Populations also reproduce sexually …

Geochemistry Of Buried Midcontinent Rift Volcanic Rocks In Iowa: Data From Well Samples, Karl E. Seifert, Raymond R. Anderson

Journal of the Iowa Academy of Science: JIAS

We analyzed welt cores and cuttings from deep wells into Precambrian igneous rocks from five separate pacts of the buried Midcontinent Rife System in Iowa for major and trace elements. A total of 21 samples, 9 cores and 12 cuttings, were analyzed for trace elements by instrumental neutron activation analysis (INAA) and 11 of these, 9 cores and 2 cuttings, were analyzed for major elements by inductively coupled plasma (ICP) analysis.

Pathogenicity Of Septoria Aquilina Isolated From Black Hills Bracken, A. Gabel, C. Salazar

Journal of the Iowa Academy of Science: JIAS

Septoria aquilina, a pathogenic fungus isolated from Pteridium aquilinum growing in the Black Hills was studied from 1991-1995. S. aquilina sprayed at 8,000 conidia/ml on transplanted fronds followed by high humidity caused severe necrosis seven days after inoculation and disease severity increased until fronds died. Severe necrosis also developed from inoculations at 4,000 and 2,000 conidia/ml. Less severe symptoms developed from inoculations at 1,000 conidia/ml. Inoculations at 4,000 conidia/ml not followed by high humidity caused less necrosis than inoculations at the same concentration with high humidity. Inoculations at 4,000, 2,000, and 1,000 conidia/ml on fronds grown from spores caused similar …

Awards And Recognition, Iowa Academy Of Science, 1996

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Index For Volume 103

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Linking Sediment Transport And Stratigraphy On The Continental Shelf, Patrica Wiberg, David Cacchione, Richard Sternberg, L. Donelson Wright

VIMS Articles

The goal of the shelf sediment dynamics component of STRATAFORM is to link sediment transport processes active on the continental shelfto the formation and preservation of event beds inshelf sediment deposits. An approach combining
shelf sediment-transport models with high-resolution measurements of water-column and bed properties over periods from several months to several
years allows us to make quantitative estimates of bed modification caused by sediment resuspension during episodic transport events.

Phosphorous Limitation And Trophic Status In Limestone Quarry Lakes, Dade County, Fl, Isaac Peter Chase

HCNSO Student Theses and Dissertations

While limestone quarry lakes have existed in South Florida for many years, only recently have they received serious scrutiny. A thorough understanding of the trophic dynamics of these lakes has yet to be achieved. Questions have arisen as to the value of these lakes for such purposes as water reclamation, conservation, and recreational use. The purpose of this study was twofold, 1) to investigate the trophic processes within these lakes with special regard to phosphorus limitation, and 2) to help provide a better understanding of the linmology of these lakes, specifically through the quantification and identification of the invertebrate life …

Diet And Seasonal Feeding Habits Of The Yellow Stingray, Urolophus Jamaicensis, T. Patrick Quinn

HCNSO Student Theses and Dissertations

Urolophus jamaicensis, the yellow stingray, is a common elasmobranch found on and around the coral reefs off Florida's southeastern coast. Its diet consists of polychaetes, crustaceans, nemerteans, sipunculids, nematodes, and chaetognaths with polychaetes and crustaceans comprising almost 67% of the stomach contents by volume. There does not appear to be any diet preference between the male and females stingrays. The seasonal changes in diet preference are limited to an increase in the proportion of polychaetes found in the stomach during spring when compared to fall.

Regulation Of Beta-Glucosidase In Marine Bacteria, Dennis Stetter

HCNSO Student Theses and Dissertations

The following is a study of the regulation of production of a catabolic enzyme, beta-glucosidase, by isolated strains of marine bacteria. Catabolic enzymes transform organic matter to monosaccharides which are utilized as an energy source for growth by bacteria. The bacterial strains were isolated from the Gulf Stream off the coast of Florida, as well as from particulate matter collected from waters adjacent to the Florida coast.

The first section describes the preparation of a liquid medium using sterile saltwater supplemented with inorganic nutrients and a carbohydrate component. This medium allowed growth of marine bacteria under carbohydrate-limiting conditions. A solid …

Factors Affecting Attwater's Prairie-Chicken Decline On The Attwater Prairie Chicken, Michael E. Morrow, Robert S. Adamcik, Jenny D. Friday, Lloyd B. Mckinney

United States Geological Survey: Staff Publications

We examined the association between changes in the number of Attwater's prairie- chicken (Tympanuchus cupido attwateri) on the Attwater Prairie Chicken National Wildlife Refuge from 1972 to 1993 and changes in refuge management practices (burning and grazing). We also examined the relationship of prairie-chicken population increases and decreases on the refuge to rainfall and off-refuge prairie-chicken populations. Burning within the prairie-chicken's core habitat on the refuge and variability in grassland structure were directly correlated (P< 0.05) with increases and declines in prairie-chicken populations. Refuge population increases and declines were inversely correlated (P< 0.1) with average April rainfall/event, May absolute departure from long-term average rainfall, May number of rainfall events, annual absolute departure of rainfall from the long-term average, and the annual number of rainfall events. Refuge population increases and declines were directly correlated (P < 0.1) with off-refuge populations, although the off- refuge population decline began 4 years earlier than on-refuge.

Observations On Bats At Badlands National Park, South Dakota, Michael A. Bogan, Jeffrey G. Osborne, Jennifer A. Clarke

United States Geological Survey: Staff Publications

During the summers of 1992 and 1993, we conducted a survey of bats at Badlands National Park, South Dakota. Using mist nets, we captured bats and recorded species, sex, age class, and reproductive condition for each individual netted. We recorded five species, Myotis ciliolabrnm (n = 198), M. thysanodes (29), M volans (13), Eptesicus foscus (91), and Plecotus tawnsendii (43), previously known from the park. In addition, we added four species, M lucifugus (18), M. septentrionalis (9), Lasionycteris noctivagans (1), and Lasiurns cinereus (3) to the confirmed fauna of the park. Most bats captured were male (76.3%) although maternity colonies …

Detailed Observations Of California Foreshock Sequences: Implications For The Earthquake Initiation Process, Douglas A. Dodge, Gregory C. Beroza, W. L. Ellsworth

United States Geological Survey: Staff Publications

We find that foreshocks provide clear evidence for an extended nucleation process before some earthquakes. In this study, we examine in detail the evolution of six California foreshock sequences, the 1986 Mount Lewis (M_L = 5.5), the 1986 Chalfant (M_L = 6.4), the 1986 Stone Canyon( M_L = 4.7), the 1990 Upland (M_L = 5.2), the 1992 Joshua Tree (M_w= 6.1), and the 1992 Landers (M_w = 7.3) sequence. Typically, uncertainties in hypocentral parameters are too large to establish the geometry of foreshock sequences and hence to understand their evolution. However, the similarity …

Origin Of The Late Quaternary Dune Fields Of Northeastern Colorado, Daniel R. Muhs, Thomas W. Stafford, Scott D. Cowherd, Shannon A. Mahan, Rolf Kihl, Paula B. Maat, Charles A. Bush, Jennifer Nehring

United States Geological Survey: Staff Publications

Stabilized eolian deposits, mostly parabolic dunes and sand sheets, cover much of the landscape of northeastern Colorado and adjacent parts of southwestern Nebraska in four geographically distinct dune fields. Stratigraphic and soil-geomorphic relations and accelerator radiocarbon dating indicate that at least three episodes of eolian sand movement occurred between 27 ka and 11 ka. possibly between 11 ka and 4 ka. and within the past 1.5 ka. Thus, eolian sand deposition took place under both glacial and interglacial climatic conditions. In the youngest episodes of eolian sand movement. Holocene parabolic dunes partially buried Pleistocene sand sheet deposits.

Late Holocene sands …

Sources Of Variation In Counts Of Meristic Features Of Yellowstone Cutthroat Trout (Oncorhynchus Clarki Bouvieri), Carter Kruse, Wayne Hubert, Frank Rahel

United States Geological Survey: Staff Publications

We determined variability in counts of meristic features (pyloric caecae, vertebrae, pelvic fin rays, gillrakers, basibranchial teeth, scales above the lateral line, and scales in the lateral series) of Yellowstone cutthroat trout (Oncorhynchus clarki bouvieri ) by 3 independent readers, by the same reader on 3 different occasions, and among fish from 12 sampling sites within a 650-km² watershed. Genetic purity of the cutthroat trout was determined by electrophoretic analysis. Significant differences in meristic counts were observed among 3 readers and among sampling sites, but not among 3 occasions by a single reader. Scale counts were within the …

Late Pliocene Diatoms In A Diatomite From Prydz Bay, East Antarctica, Albert D. Mahood, John A. Barron

United States Geological Survey: Staff Publications

Very well-preserved Pliocene diatoms from a diatomite unit interbedded within glacial sediments at Ocean Drilling Program Site 742 in Prydz Bay, Antarctica are documented and illustrated. The presence of Thalassiosira kolbei, T torokina, Actinocyclus actinochilus, A karstenii and the absence of Nitzschia interfrigidaria, T. insigna and T. vulnifica in Sample 119-742A-15R-4, 44-46 cm constrain its age to ca. 2.2-1.8 Ma (late Pliocene). Diatoms associated with sea ice constitute 35% of the Pliocene diatom assemblage, compared with 71% of the modern sediment assemblage at the site, suggesting that sea ice was present during the late Pliocene period of deposition of the …

Kybasin: A Water Supply Assessment Model For The Kentucky River Basin, J. Herman, L. Ormsbee

KWRRI Research Reports

KYBASIN is a computer model developed for the Kentucky River Authority by the Kentucky Water Reource Research Institute (KWRRI) for the express purpose of simulating the Kentucky River Basin under a severe drought. The model was developed as part of the KWRRI Kentucky River Basin Water Supply Assessment Study. This study was authorized by the KRA in a contract with the KWRRI dated April 1, 1995. Ownership of the model is exclusively that of the Authority and specific rules governing KYBASIN'S distribution or license agreement nay be applicable. It is strongly recommended the user contact the Authority concerning this matter …

Kyrom: A Drought Management Model For The Kentucky River Basin Users Manual, J. Herman, L. Ormsbee

KWRRI Research Reports

The Kentucky River Operation and Management model is a computer application developed for the Kentucky River Authority by the Kentucky Water Resources Research Institute (KWRRI) for the purpose of simulating the Kentucky River Basin during drought periods. The model was developed as part of the KWRRI Kentucky River Basin Water Supply Assessment Study. This study was authorized by the KRA in a contract with the KWRRI dated April 1, 1995. Ownership of the model is exclusively that of the Authority and specific rules governing KYROM's distribution or license agreement may be applicable. It is strongly recommended the user contact the …

Task L Report: Summary And Evaluation Of Water Supply Studies For The Kentucky River Basin, L. Ormsbee, J. Herman, G. Blomquist, W. Hoyt

KWRRI Research Reports

This report provides a review and critique of previous water supply studies for the Kentucky River Basin. The main focus of the review is on the 1990 Harza study, entitled Phase 1 Report: Water Demands and Water Supply Yield and Deficit.

Task Lll Report: Deficit Analysis, L. Ormsbee, J. Herman

KWRRI Research Reports

This report summarizes the water supply deficit results of Phase lll of the KWRRI Kentucky River Basin Water Supply Assessment Study commissioned by the Kentucky River Authority. The purpose of Phase lll is to quantify water supply in the Kentucky River Basin during a severe drought for the existing supply system/resources under current and projected demand forecasts. A quantification of the susceptibility of the basin to a severe drought is necessary for the Authority to properly develop a long-range water supply plan.

This is part 3 of a three part Assessment Study of the River basin water supply.

Task I Report: Summary And Evaluation Of Previous Water Supply Studies For The Kentucky River Basin, Kentucky Water Resources Research Institute

KWRRI Research Reports

This report summarizes the results of Task I of the KWRRI Kentucky River Basin Water Supply Assessment Study.The KWRRI study was requested by the Kentucky River Authority in order to provide a basis for management decisions for the Kentucky River Basin. This study was necessitated as a result of unexamined or changing conditions that could significantly impact the conclusions and recommendations of the previous HARZA studies (Harza, et al, 1990; Harza, et al, 1991).

Fixed Points And Completeness, Z. Liu

Turkish Journal of Mathematics

We give five necessary and sufficient conditions for a metric space to be complete.

The Inverse Nonstationary Scattering Problem For A Hyperbolic System Of Equations On Semi-Axis, N. Sh. Iskenderov, A. Yildiz

Turkish Journal of Mathematics

In this paper, the direct and inverse nonstationary scattering problem for a hyperbolic system of n equations (n>3) on a semi-axis is studied. The coefficients of the system are uniquely determined according to scattering operator. The solution of the problem is generalized for an arbitrary natural number n applying the properties of separation of factors by means of operator transformations to some elements of the scattering operator and its inverse as well as reducing the scattering problem given on a semi-axis to the scattering problem on the whole-axis.

On Affine Selection And Separation Of Vector Valued Functions, S. Alpay, Z. Ercan

Turkish Journal of Mathematics

Let K be a Choquet simplex, E a Fr\'{e}chet space and \Phi: K \ra 2^E a map such that \Phi(x) is closed and convex for each x \in K. A sufficient condition is given for \Phi to have a continuous affine selection.This is employed to prove a separation theorem for vector valued semicontinuous functions from a Choquet simplex into an ordered Fr\'{e}chet space.

Energy And Angular Distributions Of Electrons From Ion Impact On Atomic And Molecular Hydrogen. Iv. 28–114-Kev He+ + H Collisions, Y.-Y. Hsu, M. W. Gealy, G. W. Kerby Iii, M. Eugene Rudd, D. R. Schultz, C. O. Reinhold

M. Eugene Rudd Publications

Absolute ionization cross sections for 28–114-keV helium ion impact on atomic hydrogen, differential in energy and angle of the ejected electrons, have been obtained from crossed-beam measurements and previously measured cross sections for molecular hydrogen targets. A radio frequency discharge source produced a mixed atomic and molecular target with a typical dissociation fraction of 74%. Energy spectra were measured from 1.5 to 130 eV by an electrostatic analyzer with a resolution of 5%. The angular range was 15° –160°. Results are compared with calculations based on the first Born, continuum-distorted-wave–eikonal-initial-state, and classical trajectory Monte Carlo methods. Total electron yields are …