Physical Sciences and Mathematics Commons^™

Hydroperiod Of Wetlands And Reproduction In Wood Frogs (Rana Sylvatica) And Spotted Salamanders (Ambystoma Maculatum), Mary Beth Kolozsvary

Electronic Theses and Dissertations

Many amphibians rely on wetlands for reproduction and the differential distribution of amphibian species along a gradient of wetland permanence is striking, yet not absolute. Wood frogs (Rana sylvatica) and spotted salamanders (Ambystoma maculatum) are thought to rely on seasonal wetlands for greatest breeding success, but there is little documentation of their reliance on these or other habitats. In my first chapter, I studied these species in wetlands across a hydrologic gradient from seasonal wetlands of short flood duration to permanently flooded sites. My results indicate that wood frogs have greatest reproductive effort and success in …

Public Commons For Geospatial Data: A Conceptual Model, Chakravarthy Namindi Sharad

Electronic Theses and Dissertations

A wide variety of spatial data collection efforts are ongoing throughout local, state and federal agencies, private firms and non-profit organizations. Each effort is established for a different purpose but organizations and individuals often collect and maintain the same or similar information. The United States federal government has undertaken many initiatives such as the National Spatial Data Infrastructure, the National Map and Geospatial One-Stop to reduce duplicative spatial data collection and promote the coordinated use, sharing, and dissemination of spatial data nationwide. A key premise in most of these initiatives is that no national government will be able to gather …

Dramatic Nondipole Effects In Low-Energy Photoionization: Experimental And Theoretical Study Of Xe 5s, Oliver Hemmers, Renaud Guillemin, E. P. Kanter, B. Krassig, Dennis W. Lindle, S. H. Southworth, R. Wehlitz, J. Baker, A. C. Hudson, M. Lotrakul, D. Rolles, Wayne C. Stolte, I. Tran, A. Wolska, S. Yu, M. Ya Amusia, K. T. Cheng, L. V. Chernysheva, W. R. Johnson, S. T. Manson

Environmental Studies Faculty Publications

The Xe 5s nondipole photoelectron parameter γ is obtained experimentally and theoretically from threshold to ∼200  eV photon energy. Significant nondipole effects are seen even in the threshold region of this valence shell photoionization. In addition, contrary to previous understanding, clear evidence of interchannel coupling among quadrupole photoionization channels is found.

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics - Phase Three, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The proposed work will combine chemical kinetics and hydrodynamics in target and test-loop lead-bismuth eutectic (LBE) systems to model system corrosion effects. This approach will result in a predicative tool that can be validated with corrosion test data, used to systematically design tests and interpret the results, and provide guidance for optimization in LBE system designs. The task includes two subtasks. The first subtask is to try to develop the necessary predictive tools to be able to predict the levels of oxygen and corrosion products close to the boundary layer through the use of Computational Fluid Dynamics (CFD) modeling. The …

Dose Coefficients For Radionuclides Produced In A Spallation Neutron Source, John P. Shanahan

Transmutation Sciences Physics (TRP)

Internal and external dose coefficient values have been calculated for 14 anthropogenic radionuclides which are not currently presented in Federal Guidance Reports No. 11, 12, and 13 or Publications 68 and 72 of the International Commission on Radiological Protection. Internal dose coefficient values are reported for inhalation and ingestion of 1 μm and 5 μm particulates along with the f1 values and absorption types for the adult worker. Internal dose coefficient values are also reported for inhalation and ingestion of 1 μm particulates as well as the f1 values and absorption types for members of the public. Additionally, external dose …

Inside Unlv, Gian Galassi, Carol C. Harter, Gale Sinatra

Inside UNLV

No abstract provided.

The Distribution Of Phoshorus In The Nature Preserve At Clark County Wetlands Park In Las Vegas, Rosangela Gomez Brazao

UNLV Theses, Dissertations, Professional Papers, and Capstones

The main objective of this thesis was to investigate the distribution of phosphorus among three different compartments of the Upper Pond at the Nature Preserve at the Clark County Wetlands Park in Las Vegas, NV: influent and effluent water, sediments, and plants. Samples were collected from September 2002 to January of 2003 and analyzed for phosphorus content. Results showed that the Upper Pond removed 55% of the ortho phosphate (OP) and 39% of the total phosphorus (TP) loadings during the study period. Sediment results showed that the East Outflow concentrated the most P (644.85 ± 120.26 mg P Kg'1), followed …

Learning Real-Time A* Path Planner For Sensing Closely-Spaced Targets From An Aircraft, Jason K. Howlett, Michael A. Goodrich, Timothy W. Mclain

Faculty Publications

This work develops an any-time path planner, based on the learning real-time A* (LRTA*) search, for generating flyable paths that allow an aircraft with a specified sensor footprint to sense a group of closely-spaced targets. The LRTA* algorithm searches a tree of flyable paths for the branch that accomplishes the desired objectives in the shortest distance. The tree of paths is created by assembling primitive turn and straight sections of a specified step size. The operating parameters for the LRTA* search directly influence the running time and path-length performance of the search. A modified LRTA* search is presented that terminates …

Consensus-Based Table Form Recognition, William A. Barrett, Heath E. Nielson

Faculty Publications

Zoning documents increases the resolution of indexing from the image level to the field level. A line-delimited tabular document forms a well defined series of regions. However, as image quality decreases, accurate zoning becomes increasingly difficult. Given a sequence of documents with the same layout, we present a robust zoning method which exploits both intra- and inter-document consensus to form a more accurate combined result (template) that can be applied to any other document with the same layout.

Three-Dimensional Nonlinear Evolution Ofequatorial Ionospheric Spread-F Bubbles, M. J. Keskinen, S. L. Ossakow, Bela G. Fejer

Bela G. Fejer

[1] Using numerical simulation techniques, we present the first study of the three-dimensional nonlinear evolution of an equatorial spread-F bubble. The background ionosphere used to initialize the bubble evolution is computed using a time-dependent first-principles equatorial plasma fountain model together with a prereversal enhancement vertical drift model. We find that finite parallel conductivity effects slow down both the linear and nonlinear bubble evolution compared to the two-dimensional evolution. In addition we find that bubble-like structures with extremely sharp density gradients can be generated off the equator at equatorial anomaly latitudes in agreement with recent observations.

Interlocked Open And Closed Linkages With Few Joints, Erik D. Demaine, Stefan Langerman, Joseph O'Rourke, Jack Snoeyink

Computer Science: Faculty Publications

We study collections of linkages in 3-space that are interlocked in the sense that the linkages cannot be separated without one bar crossing through another. We explore pairs of linkages, one open chain and one closed chain, each with a small number of joints, and determine which can be interlocked. In particular, we show that a triangle and an open 4-chain can interlock, a quadrilateral and an open 3-chain can interlock, but a triangle and an open 3-chain cannot interlock.

User Controlled Privacy Protection In Location-Based Services, Anuket Bhaduri

Electronic Theses and Dissertations

The rapid development of location-determining technologies has enabled tracking of people or objects more accurately than ever before and the volume and extent of tracking has increased dramatically over time. Within the broader domain of tracking technologies, location-based services (LBS) are a subset of capabilities that allow users to access information relative to their own physical location. However, the personal location information generated by such technologies is at risk of being misused or abused unless protection capabilities are built into the design of such systems. These concerns may ultimately prevent society from achieving the broad range of benefits that otherwise …

Synthesis Of Porous Monoclinic Tungsten Oxides And Their Application In Sensors, Anil Bhalchandra Waghe

Electronic Theses and Dissertations

Semiconducting metal oxide sensors are limited in their usage because of their poor detection selectivity. The current approach to achieve better selectivity in SMO detection uses prefiltering/preconcentration schemes to reduce the number of gases in contact with the sensor in combination with array-based detection. In this thesis we have investigated different materials and approaches for use as elements in an array based detection system.

One approach we have investigated involves the use of porous monoclinic WO₃ to obtain size selectivity in detection within the sensing element itself. In chapter 3 we describe the synthetic protocol used to generate high …

Pushing Blocks Is Hard, Erik D. Demaine, Martin L. Demaine, Michael Hoffmann, Joseph O'Rourke

Computer Science: Faculty Publications

We prove NP-hardness of a wide class of pushing-block puzzles similar to the classic Sokoban, generalizing several previous results [E.D. Demaine et al., in: Proc. 12th Canad. Conf. Comput. Geom., 2000, pp. 211-219; E.D. Demaine et al., Technical Report, January 2000; A. Dhagat, J. O'Rourke, in: Proc. 4th Canad. Conf. Comput. Geom., 1992, pp. 188-191; D. Dor, U. Zwick, Computational Geometry 13 (4) (1999) 215-228; J. O'Rourke, Technical Report, November 1999; G. Wilfong, Ann. Math. Artif. Intell. 3 (1991) 131-150]. The puzzles consist of unit square blocks on an integer lattice; all blocks are movable. The robot may move horizontally …

The John Muir Newsletter, Fall 2003, The John Muir Center For Environmental Studies

Muir Center Newsletters (1981-2015)

LETTER UwiVfeRsnYoFTHfi Pacific, Stockton, CA- Volume 13, Number 4 Fall 2003! uir & his Reading Interests by Ronald Limbaugh (Editor's note: Ronald Limbaugh retired in 2000 after thirty-four years at the University of the Pacific, serving concurrently as director of the John Muir Center for Regional Studies and Rockwell Hunt Professor of California History) ven without considering his published works, John Muir's surviving journals and private correspondence demonstrate that he was a voluminous writer with unusual gifts. With his family and friends— and with himself— he carried on an effusive dialog, describing events, recalling anecdotes, lecturing and philosophizing, opening a …

High-Frequency Volume And Boundary Acoustic Backscatter Fluctuations In Shallow Water, Timothy C. Gallaudet, Christian De Moustier

Center for Coastal and Ocean Mapping

Volume and boundary acoustic backscatter envelope fluctuations are characterized from data collected by the Toroidal Volume Search Sonar (TVSS), a 68 kHz cylindrical array capable of 360° multibeam imaging in the vertical plane perpendicular to its axis. The data are processed to form acoustic backscatter images of the seafloor, sea surface, and horizontal and vertical planes in the volume, which are used to attribute nonhomogeneous spatial distributions of zooplankton, fish, bubbles and bubble clouds, and multiple boundary interactions to the observed backscatter amplitude statistics. Three component Rayleigh mixture probability distribution functions (PDFs) provided the best fit to the empirical distribution …

Haptic-Geozui3d: Exploring The Use Of Haptics In Auv Path Planning, Rick Komerska, Colin Ware, Matthew D. Plumlee, Roland J. Arsenault

Center for Coastal and Ocean Mapping

No abstract provided.

Tev Black Hole Fragmentation And Detectability In Extensive Air Showers, Eun-Joo Ahn, Maximo Ave, Marco Cavaglia, Angela V. Olinto

Physics Faculty Research & Creative Works

In models with large extra dimensions, particle collisions with a center-of-mass energy larger than the fundamental gravitational scale can generate nonperturbative gravitational objects. Since cosmic rays have been observed with energies above 10⁸ TeV, gravitational effects in the TeV energy range can, in principle, be observed by ultrahigh energy cosmic ray detectors. We consider the interaction of ultrahigh energy neutrinos in the atmosphere and compare extensive air showers from TeV black hole formation and fragmentation with standard model processes. Departures from the standard model predictions arise in the interaction cross sections and in the multiplicity of secondary particles. Large …

Solving Multi-Objective Multi-Constrained Optimization Problems Using Hybrid Ants System And Tabu Search, Hoong Chuin Lau, Min Kwang Lim, Wee Chong Wan, Hui Wang, Xiaotao Wu

Research Collection School Of Computing and Information Systems

Many real-world optimization problems today are multi-objective multi-constraint generalizations of NP-hard problems. A classic case we study in this paper is the Inventory Routing Problem with Time Windows (IRPTW). IRPTW considers inventory costs across multiple instances of Vehicle Routing Problem with Time Windows (VRPTW). The latter is in turn extended with time-windows constraints from the Vehicle Routing Problem (VRP), which is extended with optimal fleet size objective from the single-objective Traveling Salesman Problem (TSP). While single-objective problems like TSP are solved effectively using meta-heuristics, it is not obvious how to cope with the increasing complexity systematically as the problem is …

Towards A Role-Based Metadata Scheme For Educational Digital Libraries: A Case Study In Singapore, Dian Melati Md Ismail, Ming Yin, Yin-Leng Theng, Dion Hoe-Lian Goh, Ee Peng Lim

Research Collection School Of Computing and Information Systems

In this paper, we describe the development of an appropriate metadata scheme for GeogDL, a Web-based digital library application containing past-year examination resources for students taking a Singapore national examination in geography. The new metadata scheme was developed from established metadata schemes on education and e-learning. Initial evaluation showed that a role-based approach would be more viable, adapting to the different roles of teachers/educators and librarians contributing geography resources to GeogDL. The paper concludes with concrete implementation of the role-based metadata schema for GeogDL.

A Generic Object-Oriented Tabu Search Framework, Hoong Chuin Lau, Wee Chong Wan, Xiaomin Jia

Research Collection School Of Computing and Information Systems

Presently, most tabu search designers devise their applications without considering the potential of design and code reuse, which consequently prolong the development of subsequent applications. In this paper, we propose a software solution known as Tabu Search Framework (TSF), which is a generic C++ software framework for tabu search implementation. The framework excels in code recycling through the use of a welldesigned set of generic abstract classes that clearly define their collaborative roles in the algorithm. Additionally, the framework incorporates a centralized process and control mechanism that enhances the search with intelligence. This results in a generic framework that is …

Just-In-Time Browsing For Digitized Microfilm And Other Similar Image Collections, William A. Barrett, Douglas J. Kennard

Faculty Publications

This paper describes “Just-In-Time Browsing” (JITB), a method for image browsing (at modem-like speed) in which image data is transmitted and presented to the user progressively, in prioritized order, based on image content and user interaction. Spatial resolution and grayscale or color fidelity is increased first for the portions of the image that are immediately of most interest to the user. JITB is specifically geared toward digitized microfilm and other similar document image collections, although it can also be used for other types of images. A series of common browsing tasks performed by multiple users demonstrates that JITB compares favorably …

Electrical Conductivity Measurements Of Lithium-Ammonia Solutions, Mariana Constantin Barbu

Masters Theses

The topic covered in this thesis is the study of electronic interactions for liquid metal-ammonia solutions, lithium-ammonia solutions in particular. To obtain a theoretical understanding of so-called correlated electron systems.

The work focuses on sample creation and measurement of electrical conductivity of lithium-ammonia solutions varying with temperature for different concentrations. We have taken measurements in liquid lithium-ammonia mixtures using four-wire method to minimize the contact resistance. We have shown how it is possible to carry out accurate measurements of the electrical conductivity in these systems with the four wire measurements.

Investigation Of The Relationship Between Particulate Bound Mercury And Properties Of Fly Ash In A Full-Scale 100 Mwe Pulverized Coal Combustion Boiler, Sen Li

Masters Theses & Specialist Projects

There is an increasing concern over mercury emissions from coal-fired boilers. Coal-fired power generation accounts for approximately 33% of total mercury emission in the United States. Once it is emitted into the atmosphere and deposited on land or water, mercury can transform into methylmercury, an organic form. Mercury can then enter the food chain, which poses a potential threat to human health and the environment. To study the relationship between particulate bound mercury and fly ash properties, fly ash samples were collected from the mechanical hopper (MHP) and the electrostatic precipitator (ESP) of a 100 MWe pulverized coal-fired boiler and …

Model-Independent Quantum Approach For Intense Laser Detachment Of A Weakly Bound Electron, M.V. Frolov, N. L. Manakov, E.A. Pronin, Anthony F. Starace

Anthony F. Starace Publications

We present a model-independent theory for laser detachment of a weakly bound electron having a nonzero angular momentum. Our treatment reduces to the well-known Keldysh result for tunnel ionization upon neglecting rescattering effects. Numerical results for the above-threshold detachment spectrum of a negative ion having an outer p electron show significant modification of the rescattering plateau as compared to that for an ion having an outer s electron.

Effects Of Nitrogen Deposition And Flow Permanence On Stream Organic Matter Dynamics, Michael Andrew Joseph Chadwick

Electronic Theses and Dissertations

The objective of this study was to investigate the effects of N enrichment and flow permanence on stream organic matter dynamics at the Bear Brook Watershed in Maine (BBWM). BBWM is a paired-catchment manipulation of atmospheric (NH₄)₂SO₄ deposition, and the goal of the experiment is to understand how increased N affects forested catchments. The treatment has increased stream nitrate and foliar N concentrations in the treatment watershed. Because streams draining BBWM are intermittent, this investigation provided an opportunity to investigate the combined effects of stream flow permanence and human alteration of N cycling in a …

Computational Models For Diffusion Of Second Messengers In Visual Transduction, Harihar Khanal

Publications

The process of phototransduction, whereby light is converted into an electrical response in retinal rod and cone photoreceptors, involves, as a crucial step, the diffusion of cytoplasmic signaling molecules, termed second messengers. A barrier to mathematical and computational modeling is the complex geometry of the rod outer segment which contains about 1000 thin discs. Most current investigations on the subject assume a well-stirred bulk aqueous environment thereby avoiding such geometrical complexity. We present theoretical and computational spatio-temporal models for phototransduction in vertebrate rod photoreceptors, which are pointwise in nature and thus take into account the complex geometry of the …

Self-Potential, Soil Co2 Flux, And Temperature On Masaya Volcano, Nicaragua, J. L. Lewicki, Charles B. Connor, K. St-Armand, J. Stix, W. Spinner

School of Geosciences Faculty and Staff Publications

We investigate the spatial relationship between self-potential (SP), soil CO₂ flux, and temperature and the mechanisms that produce SP anomalies on the flanks of Masaya volcano, Nicaragua. We measured SP, soil CO₂ fluxes (× 10⁴ g m⁻² d⁻¹), and temperatures (26 to 80°C) within an area surrounding a normal fault, adjacent to Comalito cinder cone (2002–2003). These variables are well spatially correlated. Wavelengths of SP anomalies are ≤100 m, and high horizontal SP gradients flank the region of elevated flux and temperature. Carbon isotopic compositions of soil CO₂ (δ¹³C = −3.3 …

Photofragmentation Dynamics Of Core-Excited Water By Anion-Yield Spectroscopy, Wayne C. Stolte, M. M. Sant'anna, Gunnar Ohrwall, Maria Novella Piancastelli, I. Dominguez-Lopez, Dennis W. Lindle

Chemistry and Biochemistry Faculty Research

Partial-anion and- cation yields from H₂O are presented for photon energies near the oxygen K edge. The O^- yield exhibits a feature above threshold attributed to doubly excited states, in contrast to the H^- and cation yields, which are nearly featureless above threshold. Additionally, the lack of the OH^- fragment indicates radiative decay and provides a negligible amount of anion formation.

The Characteristics That Control The Stability Of Eroding Coastal Bluffs In Maine, Corinn C. Keblinsky

Electronic Theses and Dissertations

Bluffs of glacigenic sediment exist along 53% of the tidal shoreline of Maine. Under the current regime of rising sea level, waves, groundwater, and sub-aerial processes easily erode these materials. The hazardous nature of the bluffs is not widely recognized by the public, and new homeowners are often shocked to find out that their property is disappearing. To better educate the public, the Maine Geological Survey is mapping the stability of coastal bluffs. This report utilizes that database along with other available data to determine what controls the relative stability of bluffs. A geographic information system (GIs) was used to …