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2010

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Articles 4201 - 4230 of 8620

Full-Text Articles in Physical Sciences and Mathematics

The Influence Of Mechanical Circulation On Water Column Stability And Dissolved Oxygen In Stratified Lakes, Paal Engebrigtsen Apr 2010

The Influence Of Mechanical Circulation On Water Column Stability And Dissolved Oxygen In Stratified Lakes, Paal Engebrigtsen

Civil & Environmental Engineering Theses & Dissertations

Surface circulators have been used in wastewater and industrial lagoons for many years, but only recently have they been designed for lakes and reservoirs as a water quality management tool. Their relatively low capital investment and operational costs make them an attractive chemical free option for ameliorating the symptoms of eutrophication. Little research has been conducted on their effectiveness in impacting water quality. Today many lake managers are waiting for independent research on surface circulators' performance before installing such systems.

The Occoquan Reservoir was the primary site for a study conducted to examine the influence of surface circulation on water …


Ecological And Genetic Status Of The Purple Pitcher Plant, Sarracenia Purpurea L., In Maryland And Virginia, Philip M. Sheridan Apr 2010

Ecological And Genetic Status Of The Purple Pitcher Plant, Sarracenia Purpurea L., In Maryland And Virginia, Philip M. Sheridan

Biological Sciences Theses & Dissertations

Sarracenia purpurea is a rare wetland plant in Virginia and a threatened species in Maryland, with two potential subspecies in the region. I utilized restriction fragments from the intron of the chalcone synthase gene to compare S. purpurea populations and determine whether the subspecies concept was supported. I performed a census of existing populations, compiled all known historical data on the species, and investigated the reasons for the species demise and predicted dates of extinction. Bloom phenology was examined to see if climate change may have influenced bloom period. Soil, vegetation, and climatic information was obtained to determine if taxonomic …


Nuclear Electromagnetic Currents In Chiral Effective Field Theory, Saori Pastore Apr 2010

Nuclear Electromagnetic Currents In Chiral Effective Field Theory, Saori Pastore

Physics Theses & Dissertations

A nucleon-nucleon potential and consistent nuclear electromagnetic currents are derived in chiral effective field theory retaining pions and nucleons as explicit degrees of freedom. The calculation of the potential is carried out up to next-to-next-to leading order (N2LO), while the currents include up to N3LO corrections. The potential at N2 LO and currents at N3LO consist of two-pion-exchange and contact contributions. The currents are then utilized to study a number of low-energy electromagnetic observables induced by magnetic dipole transitions, such as the deuteron and trinucleon magnetic moments and the np, nd and n …


Exclusive Π- Electro-Production From The Neutron In The Resonance Region, Jixie Zhang Apr 2010

Exclusive Π- Electro-Production From The Neutron In The Resonance Region, Jixie Zhang

Physics Theses & Dissertations

The study of baryon resonances is crucial to our understanding of nucleon structure. Although the excited states of the proton have been studied in great detail, there are very few data available for the neutron resonances because of the difficulty inherent in obtaining a free neutron target. To overcome this limitation, the spectator tagging technique was used in one of the CEBAF Large Acceptance Spectrometer (CLAS) collaboration experiments, Barely off-shell Nuclear Structure (BoNuS), in Hall-B at Jefferson Lab. We have constructed a radial time projection chamber (RTPC) based on the gaseous electron multiplier (GEM) technology to detect low momentum …


Providing Location Security In Vehicular Ad Hoc Networks, Gongjun Yan Apr 2010

Providing Location Security In Vehicular Ad Hoc Networks, Gongjun Yan

Computer Science Theses & Dissertations

Location is fundamental information in Vehicular Ad-hoc Networks (VANETs). Almost all VANET applications rely on location information. Therefore it is of importance to ensure location information integrity, meaning that location information is original (from the generator), correct (not bogus or fabricated) and unmodified (value not changed). We present validation mechanisms to provide location integrity for VANETs. In the initial mechanism, we assume that all vehicles are equipped with a radar, a GPS receiver, and a transceiver. Since radar has a limited radar range and transceiver has a limited transmission range, we build network cells as a security unit as well …


Molecular Characterization Of The Soluble Fraction Of Atmospheric Particulate Matter Obtained By Chemical Oxidation With Nitric Acid, Amanda Susan Priest Apr 2010

Molecular Characterization Of The Soluble Fraction Of Atmospheric Particulate Matter Obtained By Chemical Oxidation With Nitric Acid, Amanda Susan Priest

Chemistry & Biochemistry Theses & Dissertations

The availability of information regarding the composition of ambient atmospheric particulate matter and the transformations that these compounds may undergo upon atmospheric transit is surprisingly absent. Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry is used in this study to rapidly evaluate the composition of the water-soluble organic fraction of standard and collected atmospheric particulate matter samples, and the changes that these mixtures undergo upon oxidation with nitric acid. The standard samples include representative particulate matter collected over the course of a year in Washington, D.C. and particulate matter from the exhaust of a diesel-powered engine. The collected sample …


Selective Phase-Based De-Weathering (Spdw), Christopher Morris Apr 2010

Selective Phase-Based De-Weathering (Spdw), Christopher Morris

Electrical & Computer Engineering Theses & Dissertations

No Abstract.


How To Improve Project Management For Agile Federation Development, Priyanka Kotikalpudi Apr 2010

How To Improve Project Management For Agile Federation Development, Priyanka Kotikalpudi

Engineering Management & Systems Engineering Theses & Dissertations

Developing a simulation federation out of a variety of heterogeneous simulation solutions is a complex task requiring very effective project management support in order to accomplish the common objectives and goals of this M&S federation. This thesis study conducts a detailed survey of available literature to identify the project management methods that can be extended to be applied to manage the development of simulation systems. The literature review led to the following two main results: (a) in general, there is insufficient literature dealing with M&S challenges for project management, (b) in particular, the two challenges of often changing requirements leading …


Conformational Change And Topological Stability Of Proteins, Jeffrey Andrew Tibbitt Apr 2010

Conformational Change And Topological Stability Of Proteins, Jeffrey Andrew Tibbitt

Chemistry & Biochemistry Theses & Dissertations

The conformation and topology of a protein changes when stabilizing forces are absent, but the mechanisms by which these changes occur remains elusive. This dissertation aims to broaden the understandings. On the conformational level, the M20 loop conformers of E. coli dihydrofolate reductase are interrogated to identify factors responsible for their stability as well as to determine how one conformer might change into another. Molecular dynamics is used to simulate the open, closed and occluded conformers (observed in X-ray crystal structures) under a series of different single ligand conditions. Analysis shows that all open conformers move to a similar new …


A Test Of The Area Of Refuge Hypothesis In Indo-Pacific Marine Biogeography, Jonnell C. Sanciangco Apr 2010

A Test Of The Area Of Refuge Hypothesis In Indo-Pacific Marine Biogeography, Jonnell C. Sanciangco

Biological Sciences Theses & Dissertations

Many hypotheses have been proposed to explain the marine biogeographic patterns of species richness of the Indo-Pacific. One of these hypotheses suggests that available habitat area is the main predictor of species richness. This is the basis for the area of refuge hypothesis that attempts to explain the global maxima of species richness found in the Coral Triangle, the area encompassing mostly the Philippines, Indonesia, and Malaysia. This species-area effect also has habitat heterogeneity as a potential component. The purpose of this study is to test the effects of habitat availability predictors, such as shallow water area and coastline length …


Towards A Formal Theory Of Interoperability, Saikou Y. Diallo Apr 2010

Towards A Formal Theory Of Interoperability, Saikou Y. Diallo

Computational Modeling & Simulation Engineering Theses & Dissertations

This dissertation proposes a formal theory of interoperability that explains 1) what interoperability is as opposed to how it works, 2) how to tell whether two or more systems can interoperate and 3) how to identify whether systems are interoperating or merely exchanging bits and bytes. The research provides a formal model of data in M&S that captures all possible representations of a real or imagined thing and distinguishes between existential dependencies and transformational dependencies. Existential dependencies capture the relationships within a model while transformational dependencies capture the relationships between interactions with a model. These definitions are used to formally …


Rao's Quadratic Entropy And Some New Applications, Yueqin Zhao Apr 2010

Rao's Quadratic Entropy And Some New Applications, Yueqin Zhao

Mathematics & Statistics Theses & Dissertations

Many problems in statistical inference are formulated as testing the diversity of populations. The entropy functions measure the similarity of a distribution function to the uniform distribution and hence can be used as a measure of diversity. Rao (1982a) proposed the concept of quadratic entropy. Its concavity property makes the decomposition similar to ANOVA for categorical data feasible. In this thesis, after reviewing the properties and providing a modification to quadratic entropy, various applications of quadratic entropy are explored. First, analysis of quadratic entropy with the suggested modification to analyze the contingency table data is explored. Then its application to …


Urban Elementary Students' Views Of Environmental Scientists, Environmental Caretakers And Environmentally Responsible Behaviors, Patricia Lynne Horne Apr 2010

Urban Elementary Students' Views Of Environmental Scientists, Environmental Caretakers And Environmentally Responsible Behaviors, Patricia Lynne Horne

Teaching & Learning Theses & Dissertations

The purpose of this research was to determine the nature of the relationship between urban elementary fifth graders, environmental workers, and the environment. The study examined 320 urban fifth grade elementary students' drawings of environmental scientists (DAEST) and environmental caretakers (DAECT). Additionally, semi-structured interviews were included to elucidate student illustrations. The study's sample represented one-third of all fifth graders in the mid-Atlantic school district selected for this research. Approximately 5% of participants were chosen for follow-up semi-structured interviews based on their illustrations.

A general conclusion is some of the stereotypes, particularly related to gender, revealed in prior research (Barman, 1999, …


Beyond The Born Approximation: A Precise Comparison Of E+P And E-P Elastic Scattering In The Cebaf Large Acceptance Spectrometer (Clas), Megh Raj Niroula Apr 2010

Beyond The Born Approximation: A Precise Comparison Of E+P And E-P Elastic Scattering In The Cebaf Large Acceptance Spectrometer (Clas), Megh Raj Niroula

Physics Theses & Dissertations

How well we know the structure of the proton depends on our knowledge of the form factors of the proton. The ratio of the electromagnetic form factors of the proton measured by the Rosenbluth and the polarization transfer methods differ by a factor of 3 at four momentum transfer squared (Q²)=5.6 GeV². The two photon exchange (TPE) effect is the leading candidate to explain this discrepancy. The theoretical estimates of the TPE effect are model dependent so precise measurement is required to resolve this problem. The TPE effect can be measured in a model independent way by measuring …


Expression Invariant Face Recognition Using Shifted Phase-Encoded Joint Transform Correlation Technique, Trisha Ahmed Apr 2010

Expression Invariant Face Recognition Using Shifted Phase-Encoded Joint Transform Correlation Technique, Trisha Ahmed

Electrical & Computer Engineering Theses & Dissertations

A new face recognition algorithm using a synthetic discriminant function based shifted phase-encoded fringe-adjusted joint transform correlation (SDF-SPFJTC) technique is proposed. The dark region in an input image is enhanced by using a nonlinear technique named ratio enhancement in gaussian neighborhood (REIGN). Histogram equalization and Gaussian smoothing are then performed to the enhanced face images and the synthetic discriminant function (SDF) image before they are subjected to the joint transform correlation process. The two distinct correlation peaks produced on extreme ends of the SPFJTC plane signifies the recognition of a potential target. A post processing step utilizes the peak-to-clutter ratio …


A Genetic Algorithm Approach For Optimized Routing, Pavithra Gudur Apr 2010

A Genetic Algorithm Approach For Optimized Routing, Pavithra Gudur

Electrical & Computer Engineering Theses & Dissertations

Genetic Algorithms find several applications in a variety of fields, such as engineering, management, finance, chemistry, scheduling, data mining and so on, where optimization plays a key role. This technique represents a numerical optimization technique that is modeled after the natural process of selection based on the Darwinian principle of evolution. The Genetic Algorithm (GA) is one among several optimization techniques and attempts to obtain the desired solution by generating a set of possible candidate solutions or populations. These populations are then compared and the best solutions from the set are retained. Subsequently, new candidate solutions are produced, and the …


Continuous Spatial Assignment Of Moving Users, Hou U Leong, Kyriakos Mouratidis, Nikos Mamoulis Apr 2010

Continuous Spatial Assignment Of Moving Users, Hou U Leong, Kyriakos Mouratidis, Nikos Mamoulis

Research Collection School Of Computing and Information Systems

Consider a set of servers and a set of users, where each server has a coverage region (i.e., an area of service) and a capacity (i.e., a maximum number of users it can serve). Our task is to assign every user to one server subject to the coverage and capacity constraints. To offer the highest quality of service, we wish to minimize the average distance between users and their assigned server. This is an instance of a well-studied problem in operations research, termed optimal assignment. Even though there exist several solutions for the static case (where user locations are fixed), …


La Historia De La Energía Y Desarrollo En Una Comunidad Rural: El Uso E Historia De La Energía En Santa Rosa De Pacto Y Las Implicaciones Para El Futuro De Los Países En Vías De Desarrollo, Julie Lapidus Apr 2010

La Historia De La Energía Y Desarrollo En Una Comunidad Rural: El Uso E Historia De La Energía En Santa Rosa De Pacto Y Las Implicaciones Para El Futuro De Los Países En Vías De Desarrollo, Julie Lapidus

Independent Study Project (ISP) Collection

A medida que los países en vías de desarrollo continúan desarrollándose, sus contribuciones al cambio climático sólo continuarán aumentando. Actualmente, un país en vías de desarrollo (China) es el mayor productor del dióxido de carbono. Por eso, esta investigación se enfocó en el uso, la historia y el futuro de la energía de un pueblo rural en Ecuador (Santa Rosa de Pacto) que tiene energía eléctrica desde hace sólo ocho años. Este estudio de casos prácticos ayuda a la comprensión de la frecuencia y cambio del desarrollo de la energía en países en vías del desarrollo, particularmente en regiones rurales. …


Coordination Chemistry Of Tetra(Pyrazolyl)-Lutidine Ligands And Derivatives, Tyler James Morin Apr 2010

Coordination Chemistry Of Tetra(Pyrazolyl)-Lutidine Ligands And Derivatives, Tyler James Morin

Dissertations (1934 -)

There is current interest in the coordination chemistry of simple AE4 pentadentate ligands that occupy one axial (A) and four equatorial (E) positions about a given transition metal center considering that systems capable of mediating spectacular organic transformations such as alkane oxidation have been identified. The discovery of new systems will improve understanding of C-H bond activation processes which is critical to help make more efficient use of the currently diminishing fossil fuel supplies. As such, a new pentadentate ligand α,α,α',α'-tetra(pyrazolyl)lutidine (pz4lut) and its derivatives pz4,4lut, (pz4, = 4-methylpyrazole); pz*4lut, (pz* = 3,5-dimethylpyrazole); pzDIP4lut, (pzDIP = 3,5-diisopropylpyrazole) have been synthesized …


Nonlinear Estimation For Arrays Of Chemical Sensors, Randy Paffenroth, Jason Yosinski Mar 2010

Nonlinear Estimation For Arrays Of Chemical Sensors, Randy Paffenroth, Jason Yosinski

Randy C. Paffenroth

Reliable detection of hazardous materials is a fundamental requirement of any national security program. Such materials can take a wide range of forms including metals, radioisotopes, volatile organic compounds, and biological contaminants. In particular, detection of hazardous materials in highly challenging conditions — such as in cluttered ambient environments, where complex collections of analytes are present, and with sensors lacking specificity for the analytes of interest — is an important part of a robust security infrastructure. Sophisticated single sensor systems provide good specificity for a limited set of analytes but often have cumbersome hardware and environmental requirements. On the other …


Integrated Health Care System: An Approach To Sustainable Development, Nat Quansah Mar 2010

Integrated Health Care System: An Approach To Sustainable Development, Nat Quansah

Nat Quansah

No abstract provided.


Cap-And-Trade Legislation, John C. Dernbach Mar 2010

Cap-And-Trade Legislation, John C. Dernbach

John C. Dernbach

No abstract provided.


Hard X-Ray Emission From The Massive Star-Forming Region On 2: Discovery With Xmm-Newton., L. M. Oskinova, R. A. Gruendl, R. Ignace, Y.-H. Chu, W.-R. Hamann, A. Feldmeier Mar 2010

Hard X-Ray Emission From The Massive Star-Forming Region On 2: Discovery With Xmm-Newton., L. M. Oskinova, R. A. Gruendl, R. Ignace, Y.-H. Chu, W.-R. Hamann, A. Feldmeier

Richard Ignace

We obtained X-ray XMM-Newton observations of the open cluster Berkeley 87 and the massive star-forming region (SFR) ON 2. In addition, archival infrared Spitzer Space Telescope observations were used to study the morphology of ON 2, to uncover young stellar objects, and to investigate their relationship with the X-ray sources. It is likely that the SFR ON 2 and Berkeley 87 are at the same distance, 1.23 kpc, and hence are associated. The XMM-Newton observations detected X-rays from massive stars in Berkeley 87 as well as diffuse emission from the SFR ON 2. The two patches of diffuse X-ray emission …


Nevada Interagency Volunteer Program: Helping Hands Across Public Lands – Phase Ii: Quarterly Progress Report, Period Covering January 1– March 31, 2010, Margaret N. Rees Mar 2010

Nevada Interagency Volunteer Program: Helping Hands Across Public Lands – Phase Ii: Quarterly Progress Report, Period Covering January 1– March 31, 2010, Margaret N. Rees

Get Outdoors Nevada

  • The number of records in the volunteer database increased by 2% over the last quarter. The database now contains 6,179 records.
  • Website activity remains secure, recording an average of 97,141 hits per month and an average of 9,227 pages viewed per month.
  • Volunteer fall training has been completed.
  • Volunteer spring training has been scheduled.
  • The Interagency Volunteer Program supported 21 events.
  • The 21 events posted on GON recruited 1,038 volunteers which resulted in 4,680 volunteer hours contributed to helping to protect our public lands.


Back Matter Mar 2010

Back Matter

Journal of Digital Forensics, Security and Law

No abstract provided.


Lake Mead National Recreation Area Monitoring And Evaluation Of Sensitive Wildlife: Quarterly Progress Report, Period Ending March 31, 2010, Margaret N. Rees Mar 2010

Lake Mead National Recreation Area Monitoring And Evaluation Of Sensitive Wildlife: Quarterly Progress Report, Period Ending March 31, 2010, Margaret N. Rees

Wildlife Monitoring

Project 1. Relict Leopard Frog Monitoring, Management, and Research

  • All milestones and deliverables are on schedule
  • Translocation program initiated for this year with egg mass collections in early spring
  • Tadpole rearing underway, first releases schedule for the end of March 2010
  • Diurnal egg mass surveys were completed at all sites
  • Nocturnal surveys initiated and in progress
  • Continuing mark-recapture efforts at Blue Point Spring initiated for spring season
  • Data transferred to County completed

Project 2. Bald Eagle Winter Monitoring and Evaluation

  • Project has essentially been completed
  • All final report deliverables were completed
  • Although not specified in the scope of work for …


Development Of Ultrasonic Detection Methods For Cancer Cells In Vivo, Jeffrey B. Goodrich Mar 2010

Development Of Ultrasonic Detection Methods For Cancer Cells In Vivo, Jeffrey B. Goodrich

Browse All Undergraduate research

A current problem in medicine and specifically breast cancer is the detection of microscopic cancer in surgical margins to ensure all of the cancer has been removed. Current methods rely on extensive pathology work that may take several days to complete. For breast cancer patients, positive findings for cancer in surgical margins require follow-up surgery to remove more tissue. Up to 50% of patients undergoing breast conservation surgery (lumpectomy) require additional surgery. A preferable method would be in vivo microscopic detection for use during surgery. Such methods would reduce risks, costs, and patient suffering that accompany follow-up operations. Ultrasound is …


Front Matter Mar 2010

Front Matter

Journal of Digital Forensics, Security and Law

No abstract provided.


Masthead Mar 2010

Masthead

Journal of Digital Forensics, Security and Law

No abstract provided.


A Generalized Multidimensional Index Structure For Multimedia Data To Support Content-Based Similarity Searches In A Collaborative Search Environment, Kasturi Chatterjee Mar 2010

A Generalized Multidimensional Index Structure For Multimedia Data To Support Content-Based Similarity Searches In A Collaborative Search Environment, Kasturi Chatterjee

FIU Electronic Theses and Dissertations

Since multimedia data, such as images and videos, are way more expressive and informative than ordinary text-based data, people find it more attractive to communicate and express with them. Additionally, with the rising popularity of social networking tools such as Facebook and Twitter, multimedia information retrieval can no longer be considered a solitary task. Rather, people constantly collaborate with one another while searching and retrieving information. But the very cause of the popularity of multimedia data, the huge and different types of information a single data object can carry, makes their management a challenging task. Multimedia data is commonly represented …