Physical Sciences and Mathematics Commons^™

The Crab Nebula's Dynamical Age As Measured From Its Northern Filamentary Jet, G. C. Rudie, R. A. Fesen, T. Yamada

Dartmouth Scholarship

We present a deep [O III] 4959,5007 image of the northern filamentary jet in the Crab Nebula taken with the 8.2m Subaru telescope. Using this image and an image taken with the KPNO 4m in 1988 (Fesen & Staker 1993), we have computed proper motions for 35 locations in the jet. The results suggest that when compared to the main body of the remnant, the jet experienced less outward acceleration from the central pulsar's rapidly expanding synchrotron nebula. The jet's apparent expansion rate yields an undecelerated explosion date for the Crab Nebula of 1055 plus or minus 24 C.E., a …

The Origin Of The Bemaraha Tsingy (Madagascar), Márton Veress, Dénes Lóczy, Zoltán Zentai, Gábor Tóth, Roland Schläffer

International Journal of Speleology

On Madagascar the most representative occurrences of tsingy are at Ankarana and Bemaraha. The tsingy are built up of giant grikes developed along cracks as well as karren features of much smaller size which cover the surfaces between grikes. We investigated the Bemaraha tsingy of Madagascar (surveyed profiles, measured grike directions, etc.) in order to reconstruct their development. The observations indicate that the majority of grikes of the tsingy are created from caves formed under the karst water table and subsequently opened up to the surface. The predominant processes may have been downward progressing dissolution or the collapse of cave …

Iowa Academy Of Science: The New Bulletin, V04n4, Winter 2008, Iowa Academy Of Science

New Bulletin

Inside This Issue:

--Message from the Executive Director

--IAS NWR Website

--Science: Our Past and Future

--Iowa Academy of Science Fellows

--IAS Board Retreat

--Announcements, Events & Deadlines

--Spotlight on Des Moines University

--Iowa Academy of Science Membership Overview

--ISTJ—Practical Science Education Applications from Iowans to the World

An Investigation Of Meromixis In Cave Pools, Lechuguilla Cave, New Mexico, David B. Levy

International Journal of Speleology

Chemical characteristics of permanent stratification in cave pools (meromixis) may provide insight into the geochemical origin and evolution of cave pool waters. The objective of this study was to test the hypothesis that some pools in Lechuguilla Cave may be subject to ectogenic meromixis, where permanent chemical stratification is induced by input of relatively saline or fresh water from an external source. However, because organic C concentrations in Lechuguilla waters are low (typically < 1 mg L^-1), biogenic meromixis resulting in O₂(g)-depleted subsurface waters is not expected. Four pools at various depths below ground surface (0 m) were studied: (1) …

Monitoring Climatological, Hydrological And Geochemical Parameters In The Père Noël Cave (Belgium): Implication For The Interpretation Of Speleothem Isotopic And Geochemical Time-Series, Sophie Verheyden, Dominique Genty, Guy Deflandre, Yves Quinif, Eduard Keppens

International Journal of Speleology

Père Noël cave climatology (air and water temperature, P_CO2), hydrology (drip rate, conductivity) and geochemistry of water and calcite deposits (δ¹⁸O, δ¹³C, Mg/Ca and Sr/Ca) where studied to better interpret stable isotopic and trace element variations of speleothems. Results of an automated monitoring station and of manual sampling between 1991 and 1998 have demonstrated the highly seasonal signal of drip rate, its control by water excess and rainfall, and, at a shorter scale to air pressure changes. The modern calcite deposit study suggests a relationship between cave calcite isotopic composition (δ¹⁸O and …

Analysis Of Residual Solvents In Pharmaceuticals By Comprehensive Two-Dimensional Gas Chromatography, Cristina Marie Crimi

Seton Hall University Dissertations and Theses (ETDs)

.

Geologic Map Of The O'Neill 1º X 2º Quadrangle, Nebraska, With Configuration Maps Of Surfaces Of Formations, Robert Diffendal, Jr., Michael R. Voorhies, E. Jane Voorhies, H. E. Lagarry, C. L. Timperley, M. E. Perkins

School of Natural Resources: Faculty Publications

SCALE 1:250,000

CONTOUR INTERVAL 200 FEET

Geology mapped principally from 1991-2000 by RFD, M.RV, E.JV, H. LG , and C.LT

Editing and layout by R.F. Diffendal, Jr. and D. Ebbeka

Map production by J. Nothwehr and L. Howard

Revised slightly 6 January 2009, 20 July 2010, 5 October 2010, 10 September 2012.

Chinese Liver Flukes In Latrine Sediments From Wong Nim’S Property, San Bernardino, California: Archaeoparasitology Of The Caltrans District Headquarters (Galley Proofs), Karl J. Reinhard, Adauto Araújo, Luciana Sianto, Julia G. Costello, Karen Swope

School of Natural Resources: Faculty Publications

Parasitological analysis of 5 sediment samples from latrine deposits spanning the time period from about 1880 to the 1930s are presented. Two sediment samples are from a latrine used by European-Americans. Three sediment samples are from latrines used by Chinese-Americans on the property of Wong Nim, an important member of the Chinese community. Two of the Chinese latrines were positive for human parasites. The human parasites encountered include the human whipworm (Trichuris trichiura), the giant intestinal roundworm (Ascaris lumbricoides, c.f.), and the Chinese liver fluke (Clonorchis sinensis). Evidence of the liver fluke is especially …

Power Laws, Discontinuities And Regional City Size Distributions, Ahjond S. Garmestan, Craig R. Allen, Colin M. Gallagher

School of Natural Resources: Faculty Publications

Urban systems are manifestations of human adaptation to the natural environment. City size distributions are the expression of hierarchical processes acting upon urban systems. In this paper, we test the entire city size distributions for the southeastern and southwestern United States (1990), as well as the size classes in these regions for power law behavior. We interpret the differences in the size of the regional city size distributions as the manifestation of variable growth dynamics dependent upon city size. Size classics in the city size distributions are snapshots of stable states within urban systems in flux.

Stable Isotope Analysis Of Upper Tithonian Limestones With Dinosaur Footprints From Kirmenjak Quarry (Istria, Croatia), Blanka Cvetko Tešović, Aleksandar Mezga, Bosiljka Glumac

Geosciences: Faculty Publications

The Kirmenjak locality of western Istria, Croatia, represents the oldest evidence of a dinosaur presence on the Adriatic-Dinaridic Carbonate Platform (ADCP). In a quarry at this locality, almost a thousand sauropod footprints are recognized in one distinctive trackbearing horizon within the Upper Tithonian limestones. The stable isotopes of oxygen and carbon, in conjunction with microfacies analysis of carbonate rocks exposed in this quarry, unravel details about the marginal marine or coastal environments in which sauropods left their footprints. Rocks from the trackbearing horizon, and laterally adjacent area, represent intertidal fenestral mudstones that form the top of a shallowing-upward succession, capped …

Fossil Palm Frond And Tree Trunk Molds: Occurrence And Implications For Interpretation Of Bahamian Quaternary Carbonate Eolianites, H. Allen Curran, Mark A. Wilson, John E. Mylroie

Geosciences: Faculty Publications

Molds of palm fronds and vertical, cylindrical structures interpreted as molds of palm tree trunks were reported from Holocene and upper Pleistocene carbonate eolianites on several islands in the Bahamas in the early 1990s. As a result of recent discoveries described herein, palm frond and tree trunk molds are now known to be widespread in Bahamian eolianites, including Holocene beds on Cat Island, Eleuthera, Lee Stocking Island of the Exuma Cays, Long Island, and Stocking Island offshore from Georgetown, Exuma. Late Pleistocene occurrences are known from Eleuthera, Long Island, Norman's Pond Cay of the Exuma Cays, and San Salvador Island. …

Multiple Sedimentary Sequences, Bird Tracks And Lagoon Beaches In Last Interglacial Oolites, Boiling Hole, North Eleuthera Island, Bahamas, Pascal Kindler, H. Allen Curran, Damiel Marty, Elias Samankassou

Geosciences: Faculty Publications

Our review of the last interglacial (Marine Isotope Stage 5e) stratigraphic record from the Boiling Hole exposure in northern Eleuthera Island, Bahamas, revealed the occurrence of two vertically stacked shallowing-upward sequences of oolitic coastal deposits showing beach facies at about 3 and 6 m above mean sea level, respectively. These beach strata dip towards the bank interior and the upper one includes a paleosurface on top of an oolitic grainstone bed with a 2-m-long bird trackway. These fossil beaches correspond to two distinctive sea-level highstands during the last interglacial that could have possibly reached +5 and +8 m above modem …

Eigenvalue Comparisons For Boundary Value Problems Of The Discrete Elliptic Equation, Jun Ji, Bo Yang

Faculty Articles

In this paper we study a boundary value problem for a discrete elliptic equation. The focus will be on the structure of the spectrum of this problem and the existence of a positive eigenvector corresponding to the smallest eigenvalue. Comparison results for the eigenvalues are also established as the coefficients of the problem changes.

Expanding The Database Curriculum, Meg Murray, Mario Guimaraes

Faculty Articles

As database concepts and technologies continue to evolve there exists a need to expand the topics included in database curricula. This is challenging given the restraints on the number of courses that can be included in a typical CS or IS program. While a set of commonly identified core concepts and principles exists, there is little consensus on what supplemental materials should be included in database courses. Through an NSF proof-of-concept grant, we designed and developed courseware incorporating the use of animations to deepen and enrich standard presentations of core database concepts and to complement database teachings as found in …

Subcoid: An Attempt To Explore Cluster-Outlier Iterative Detection Approach To Multi-Dimensional Data Analysis In Subspace, Yong Shi

Faculty Articles

Many data mining algorithms focus on clustering methods. There are also a lot of approaches designed for outlier detection. We observe that, in many situations, clusters and outliers are concepts whose meanings are inseparable to each other, especially for those data sets with noise. Clusters and outliers should be treated as the concepts of the same importance in data analysis. In our previous work [22] we proposed a cluster-outlier iterative detection algorithm in full data space. However, in high dimensional spaces, for a given cluster or outlier, not all dimensions may be relevant to it. In this paper we extend …

Fuzzyshrinking: Improving Shrinking-Based Data Mining Algorithms Using Fuzzy Concept For Multi-Dimensional Data, Yong Shi

Faculty Articles

In this paper, we present continuous research on data analysis based on our previous work on the shrinking approach. Shrinking[19] is a novel data preprocessing technique which optimizes the inner structure of data inspired by the Newton's Universal Law of Gravitation[16]in the real world. It can be applied in many data mining fields. In this approach data are moved along the direction of the density gradient, thus making the inner structure of data more prominent. It is conducted on a sequence of grids with different cell sizes. In this paper, we applied the Fuzzy concept to improve the performance …

Detecting Clusters And Outliers For Multi-Dimensional Data, Yong Shi

Faculty Articles

Nowadays many data mining algorithms focus on clustering methods. There are also a lot of approaches designed for outlier detection. We observe that, in many situations, clusters and outliers are concepts whose meanings are inseparable to each other, especially for those data sets with noise. Thus, it is necessary to treat clusters and outliers as concepts of the same importance in data analysis. In this paper, we present a cluster-outlieriterative detection algorithm, tending to detect the clusters and outliers in another perspective for noisy data sets. In this algorithm, clusters are detected and adjusted according to the intra-relationship within clusters …

Plasma Medicine, Mounir Laroussi, Alexander Fridman

Electrical & Computer Engineering Faculty Publications

Recent demonstrations of plasma technology in the treatment of living cells, tissues, and organs are creating a newfield at the intersection of plasma science and technology with biology and medicine - Plasma Medicine.

Specification And Automatic Code Generation Of The Data Layer For Data-Intensive Web-Based Applications, Sergei Golitsinski

Dissertations and Theses @ UNI

In this thesis I propose a new code generation approach to developing data-intensive web-based applications. I hypothesize that it is possible to build a code generator which will significantly improve development of data-intensive web-based applications by generating at least 50% of the data access code based on a specification of the application's data model. My main argument is that the application's data model is sufficient for deriving most of the data access functionality. To test this hypothesis I designed a data definition language, came up with a set of rules for deriving data access operations from the application's data model, …

Classification Of Chemical Reactions: Stages Of Expertise, Marilyne Stains, Vicente Talanquer

Department of Chemistry: Faculty Publications

In this study we explore the strategies that undergraduate and graduate chemistry students use when engaged in classification tasks involving symbolic and microscopic (particulate) representations of different chemical reactions. We were specifically interested in characterizing the basic features to which students pay attention when classifying chemical reactions at the symbolic and microscopic levels. We identified the categories that students create when classifying chemical reactions, and compared the performance in simple classification tasks of students with different levels of preparation in the discipline. Our results suggest that advanced levels of expertise in chemical classification do not necessarily evolve in a linear …

Charge Order, Dynamics, And Magnetostructural Transition In Multiferroic Lufe2o4, X. S. Xu, M. Angst, T. V. Brinzari, R. P. Hermann, J. L. Musfeldt, A. D. Christianson, D. Mandrus, B. C. Sales, S. Mcgill, J. -W. Kim, Z. Islam

Xiaoshan Xu Papers

We investigated the series of temperature and field-driven transitions in LuFe₂O₄ by optical and Mossbauer spectroscopies, magnetization, and x-ray scattering in order to understand the interplay between charge, structure, and magnetism in this multiferroic material. We demonstrate that charge fluctuation has an onset well below the charge ordering transition, supporting the ‘‘order by fluctuation’’ mechanism for the development of charge order superstructure. Bragg splitting and large magneto-optical contrast suggest a low-temperature monoclinic distortion that can be driven by both temperature and magnetic field.

Measurements Of The Gvd Of Water And Methanol And Laser Pulse Characterization Using Direct Imaging Methods, Timothy Scarborough, Chad Petersen, Cornelis J. Uiterwaal

C.J.G.J. Uiterwaal Publications

We report experimental values of the group velocity dispersion (GVD) of water and methanol at 800 nm. We find GVD^water ₈₀₀ = (25.71± 0.5) fs² mm⁻¹ and GVD^methanol ₈₀₀ = (33.56±0.5) fs² mm^-1. These were measured by sending 50 fs, 800 nm pulses with various amounts of chirp through a glass cell filled with a solution of fluorescein in these solvents and recording the production of visible light from the side using a commercial digital camera. This simple setup also gives quantitative information on the duration of our pulses and lets us check …

Examining The Cognitive Processes Used By Adolescent Girls And Women Scientists In Identifying Science Role Models: A Feminist Approach, Gayle A. Buck, Vicki L. Plano Clark, Diandra Leslie-Pelecky, Yun Lu, Patricia R. Cerda-Lizarraga

Diandra Leslie-Pelecky Publications

Women remain underrepresented in science professions. Studies have shown that students are more likely to select careers when they can identify a role model in that career path. Further research has shown that the success of this strategy is enhanced by the use of gender-matched role models. While prior work provides insights into the value of using role models, it does not explain the cognitive process involved in girls identifying role models from nontraditional careers for women. This feminist study addresses this gap by examining the cognitive process eighth-grade girls use in identifying a person as a science role model …

Experimental Evidence Of Strain Relaxed Domain Structure In (100)/(001)-Oriented Epitaxial Lead Titanate Thick Films Grown By Metal Organic Chemical Vapor Deposition, Hiroshi Nakaki, Yong Kwan Kim, Shintaro Yokoyama, Rikyu Ikariyama, Hiroshi Funakubo, S. K. Streiffer, Ken Nishida, Keisuke Saito, Alexei Gruverman

Alexei Gruverman Publications

Epitaxial (100)/(001)-oriented PbTiO₃ films with thickness of 2.8 μm were grown on Nb-doped (100) SrTiO₃ substrates by pulsed metal organic chemical vapor deposition. Complex domain structures consisting of c-domains (c1) and three types of a-domains (a1, a2, and a3) were observed by piezoresponse force microscopy in conjunction with high-resolution x-ray diffraction analysis. The obtained results suggest that (a2/a3) and (a1/c1) domain configurations represent mostly strain-relaxed structures. This conclusion is in good agreement with theoretical predictions made for thick films [Phys. State., Solidi 37, 329 (1976)].

Relativistic Magnetic Monopole Flux Constraints From Rice, Daniel P. Hogan, Dave Z. Besson, John P. Ralston, Ilya Kravchenko, D. Seckel

Department of Physics and Astronomy: Faculty Publications

We report an upper limit on the flux of relativistic monopoles based on the nonobservation of in-ice showers by the Radio Ice Cherenkov Experiment (RICE) at the South Pole.We obtain a 95% C.L. limit of order 10^-18 (cm² s sr)^-1 for intermediate-mass monopoles of 10⁷ ≤ γ ≤ 10¹² at the anticipated energy E_tot = 10¹⁶ GeV. This bound is over an order of magnitude stronger than all previously published experimental limits for this range of boost parameters γ and exceeds 2 orders of magnitude improvement over most of the range. We review …

Theory Of The Piezomagnetic Effect In Mn-Based Antiperovskites, Pavel Lukashev, Renat F. Sabirianov, Kirill D. Belashchenko

Department of Physics and Astronomy: Faculty Publications

Recent experimental and theoretical studies of the magnetoelectric (ME) effect in the nanocomposite structures and in laminates show an enhanced ME coefficient. These materials combine piezoelectric properties of the paramagnetic phase and piezomagnetic properties of the magnetic phase. We propose to fabricate heterostructures formed by piezoelectric materials and magnetic antiperovskites as magnetoelectric materials. We show that the magnetic structure of antiperovskite, such as Mn₃GaN, can be controlled by a small applied biaxial strain. The lowering of symmetry with the strain causes the local magnetic moments of Mn atoms to rotate from the trigonal Γ^5g structure with symmetric …

Aharonov–Bohm Phase Shifts Induced By Laser Pulses, Brett E. Barwick, Herman Batelaan

Department of Physics and Astronomy: Faculty Publications

An experimentally accessible scalar Aharonov–Bohm (AB)-effect is proposed using a ponderomotive potential induced by a pulsed laser. This ponderomotive AB (PAB)-effect is unique in that the time-averaged description is classified as type-I, whereas the underlying time-dependent theory is classified as type-II. Not only is the PAB-effect of fundamental interest, it may also be used to characterize ultrashort electron pulses (fs), using low power femtosecond lasers, which is important for ultrafast electron diffraction and microscopy.

Limited Occurrence Of Denitrification In Four Shallow Aquifers In Agricultural Areas Of The United States, Christopher T. Green, Larry J. Puckett, John Karl Böhlke, Barbara A. Bekins, Steven P. Phillips, Leon J. Kauffman, Judith M. Denver, Henry M. Johnson

United States Geological Survey: Staff Publications

The ability of natural attenuation to mitigate agricultural nitrate contamination in recharging aquifers was investigated in four important agricultural settings in the United States. The study used laboratory analyses, field measurements, and flow and transport modeling for monitoring well transects (0.5 to 2.5 km in length) in the San Joaquin watershed, California, the Elkhorn watershed, Nebraska, the Yakima watershed, Washington, and the Chester watershed, Maryland. Ground water analyses included major ion chemistry, dissolved gases, nitrogen and oxygen stable isotopes, and estimates of recharge date. Sediment analyses included potential electron donors and stable nitrogen and carbon isotopes. Within each site and …

Whole-Stream Response To Nitrate Loading In Three Streams Draining Agricultural Landscapes, John H. Duff, Anthony J. Tesoriero, William B. Richardson, Eric A. Strauss, Mark Munn

United States Geological Survey: Staff Publications

Physical, chemical, hydrologic, and biologic factors affecting nitrate (NO₃^-) removal were evaluated in three agricultural streams draining orchard/dairy and row crop settings. Using 3-d “snapshots” during biotically active periods, we estimated reachlevel NO₃^- sources, NO₃^- mass balance, in-stream processing (nitrification, denitrification, and NO₃^- uptake), and NO₃^- retention potential associated with surface water transport and ground water discharge. Ground water contributed 5 to 11% to stream discharge along the study reaches and 8 to 42% of gross NO₃^- input. Streambed processes potentially reduced 45 to 75% of ground …

Comparative Study Of Transport Processes Of Nitrogen, Phosphorus, And Herbicides To Streams In Five Agricultural Basins, Usa, Joseph L. Domagalski, Scott Ator, Richard Coupe, Kathleen Mccarthy, David Lampe, Mark Sandstrom, Nancy Baker

United States Geological Survey: Staff Publications

Agricultural chemical transport to surface water and the linkage to other hydrological compartments, principally ground water, was investigated at five watersheds in semiarid to humid climatic settings. Chemical transport was affected by storm water runoff , soil drainage, irrigation, and how streams were linked to shallow ground water systems. Irrigation practices and timing of chemical use greatly affected nutrient and pesticide transport in the semiarid basins. Irrigation with imported water tended to increase ground water and chemical transport, whereas the use of locally pumped irrigation water may eliminate connections between streams and ground water, resulting in lower annual loads. Drainage …