Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

2007

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 5341 - 5370 of 6758

Full-Text Articles in Physical Sciences and Mathematics

Categorical Properties Of Lattice-Valued Convergence Spaces, Paul Flores Jan 2007

Categorical Properties Of Lattice-Valued Convergence Spaces, Paul Flores

Electronic Theses and Dissertations

This work can be roughly divided into two parts. Initially, it may be considered a continuation of the very interesting research on the topic of Lattice-Valued Convergence Spaces given by Jager [2001, 2005]. The alternate axioms presented here seem to lead to theorems having proofs more closely related to standard arguments used in Convergence Space theory when the Lattice is L = f0; 1g:Various Subcategories are investigated. One such subconstruct is shown to be isomorphic to the category of Lattice Valued Fuzzy Convergence Spaces defined and studied by Jager [2001]. Our principal category is shown to be a topological universe …


Developing Strand Space Based Models And Proving The Correctness Of The Ieee 802.11i Authentication Protocol With Restricted Sec, Zeeshan Furqan Jan 2007

Developing Strand Space Based Models And Proving The Correctness Of The Ieee 802.11i Authentication Protocol With Restricted Sec, Zeeshan Furqan

Electronic Theses and Dissertations

The security objectives enforce the security policy, which defines what is to be protected in a network environment. The violation of these security objectives induces security threats. We introduce an explicit notion of security objectives for a security protocol. This notion should precede the formal verification process. In the absence of such a notion, the security protocol may be proven correct despite the fact that it is not equipped to defend against all potential threats. In order to establish the correctness of security objectives, we present a formal model that provides basis for the formal verification of security protocols. We …


Landscape And Geotourism: Market Typologies And Visitor Needs, Catherine Elizabeth Gorman Jan 2007

Landscape And Geotourism: Market Typologies And Visitor Needs, Catherine Elizabeth Gorman

Conference papers

Purpose: The purpose of this paper is to explore Geotourism (landscape tourism) in the context of the Irish tourism experience, to develop visitor typologies and propose an approach that will ensure greater sustainability by addressing market value and requirements through the use of marketing techniques and tools.

Methodology/Approach: An evaluation of existing geotourism resources and information was undertaken. A gap was identified in terms of marketing the Geotourism product. This gap is identified as a break the delivery of the experience to the most suitable customer and is addressed by identifying specific typologies, their requirements and making suggestions …


Selective Growth Of Single-Crystalline Zno Nanowires On Doped Silicon, Rolf Könenkamp, Robert Campbell Word, M. Dosmailov, J. Meiss, Athavan Nadarajah Jan 2007

Selective Growth Of Single-Crystalline Zno Nanowires On Doped Silicon, Rolf Könenkamp, Robert Campbell Word, M. Dosmailov, J. Meiss, Athavan Nadarajah

Physics Faculty Publications and Presentations

We report the growth of single-crystalline ZnO nanowires on n- and p-type Si wafers by electrodeposition. On strongly doped n-type Si high-quality nanowires can be grown under similar conditions as used for metallic substrates. For low electron concentrations occurring in weakly n-type or in p-type wafers, nanowire growth is inhibited. This difference allows selective growth in strongly n-type areas. The inhibited growth on weakly n-type and p-type wafers can be improved by applying stronger cathodic electrode potentials or by illuminating the growth area. The wires on n-Si show efficient electroluminescence covering the visible and extending into the ultraviolet spectral range.


Quantum Physics And Welfare Policy?, Jack C. Straton Jan 2007

Quantum Physics And Welfare Policy?, Jack C. Straton

Physics Faculty Publications and Presentations

Welfare policy is examined through the paradoxical logic of Nagarjuna’s tetralema, providing a lens through which wave-particle duality in quantum mechanics is then viewed. Through this process students are challenged to radically expand their critical-thinking horizons beyond conventional dualistic bounds. They learn not only this key property of quantum reality, but have to come to grips with the nature of knowledge itself, and the degree to which they censor their own awarenesses.


Three-Dimensional Structure Of Cdx (X= Se, Te) Nanocrystals By Total X-Ray Diffraction, S. K. Pradhan, Z. T. Deng, F. Tang, Y. Ren, Peter Moeck, V. Petkov Jan 2007

Three-Dimensional Structure Of Cdx (X= Se, Te) Nanocrystals By Total X-Ray Diffraction, S. K. Pradhan, Z. T. Deng, F. Tang, Y. Ren, Peter Moeck, V. Petkov

Physics Faculty Publications and Presentations

The three-dimensional structure of oleic acid-capped CdSe and thiol-capped CdTe nanocrystals used as quantum dots has been determined by total synchrotron radiationx-ray diffraction and atomic pair distribution function analysis. Both CdSe and CdTe are found to exhibit the zinc-blende-type atomic ordering. It is only slightly distorted in CdSe implying the presence of nanosize domains and very heavily distorted in CdTe due to the presence of distinct core-shell regions. The results well demonstrate the great potential of the experimental approach and thus encourage its wider application in quantum dot research.


Fabrication Of Carbon Nanotube-Based Nanodevices Using A Combination Technique Of Focused Ion Beam And Plasma-Enhanced Chemical Vapor Deposition, Jianfeng Wu, Micah Eastman, Timothy Gutu, Madeline Wyse, Jun Jiao, S.-M. Kim, M. Mann, Y. Zhang, K. B. Teo Jan 2007

Fabrication Of Carbon Nanotube-Based Nanodevices Using A Combination Technique Of Focused Ion Beam And Plasma-Enhanced Chemical Vapor Deposition, Jianfeng Wu, Micah Eastman, Timothy Gutu, Madeline Wyse, Jun Jiao, S.-M. Kim, M. Mann, Y. Zhang, K. B. Teo

Physics Faculty Publications and Presentations

This study focuses on the fabrication of two nanodevice prototypes which utilized vertical and horizontal carbon nanotubes used the focused ion beam to localize the catalysts, followed by plasma-enhanced chemical vapor deposition. First, metal-gated carbon nanotube field emitter arrays were fabricated on multilayer substrates containing an imbedded catalyst layer. Second, horizontally aligned single-walled carbon nanotubes were grown on a transmission electron microscopy grid. This allows the carbon nanotubes to be directly analyzed in a transmission electron microscope. It is expected that the methodology introduced here will open up opportunities for the direct fabrication of carbon nanotube based nanodevices.


A Theory And Practice Of Website Engagibility, Ronan Fitzpatrick Jan 2007

A Theory And Practice Of Website Engagibility, Ronan Fitzpatrick

Doctoral

This thesis explores the domain of website quality. It presents a new study of website quality - an abstraction and synthesis, a measurement methodology, and analysis - and proposes metrics which can be used to quantify it. The strategy employed involved revisiting software quality, modelling its broader perspectives and identifying quality factors which are specific to the World Wide Web (WWW). This resulted in a detailed set of elements which constitute website quality, a method for quantifying a quality measure, and demonstrating an approach to benchmarking eCommerce websites. The thesis has two dimensions. The first is a contribution to the …


Growth Substrate Induced Functional Changes Elucidated By Ftir And Raman Spectroscopy In In-Vitro Cultured Human Keratinocytes., Aidan Meade, Fiona Lyng, Peter Knief, Hugh Byrne Jan 2007

Growth Substrate Induced Functional Changes Elucidated By Ftir And Raman Spectroscopy In In-Vitro Cultured Human Keratinocytes., Aidan Meade, Fiona Lyng, Peter Knief, Hugh Byrne

Articles

Non-invasive measurements of cellular function in in-vitro cultured cell lines using vibrational spectroscopy require the use of spectroscopic substrates such as quartz, ZnSe and MirrIR etc. These substrates are generally dissimilar to the original in-vivo extracellular environment of a given cell line and are often tolerated poorly by cultured cell lines resulting in morphological and functional changes in the cell. The present study demonstrates various correlations between vibrational spectroscopic analyses and biochemical analyses in the evaluation of the interaction of a normal human epithelial keratinocyte cell line (HaCaT) with MirrIR and quartz substrates coated with fibronectin, laminin and gelatin. The …


Spectroscopic Characterisation Of Novel Polycyclic Aromatic Polymers, Luke O'Neill, Patrick Lynch, Mary Mcnamara, Hugh Byrne Jan 2007

Spectroscopic Characterisation Of Novel Polycyclic Aromatic Polymers, Luke O'Neill, Patrick Lynch, Mary Mcnamara, Hugh Byrne

Articles

A series of novel polyphenylenevinylene (PPV) derivative polymers were studied by absorption and photoluminescence spectroscopies. The effect of the sequential introduction of polycyclic aromatic ring substituents into the delocalized backbone was examined with relation to hypsochromatic and bathochromatic shifting. While the replacement of the phenyl units by naphthyl units results in a substantial hypsochromic shift of both the absorption and emission spectra, their subsequent substitution by anthryl units results in a bathochromic shift. The system is modeled according to, and is found to be consistent with, a previous study of donor-acceptor polyenes of varying length. The electronic structure of the …


A Systematic Study Of The Effects Of Naphthalene And Anthracene Substitution On The Properties Of Ppv Derivative Conjugated Systems, Patrick Lynch, Luke O'Neill, David Bradley, Hugh Byrne, Mary Mcnamara Jan 2007

A Systematic Study Of The Effects Of Naphthalene And Anthracene Substitution On The Properties Of Ppv Derivative Conjugated Systems, Patrick Lynch, Luke O'Neill, David Bradley, Hugh Byrne, Mary Mcnamara

Articles

The systematic synthesis of poly(phenylvinylene) (PPV) derivatives by the Wittig-Horner reaction is reported. The phenyl units of the PPV structure are methodically substituted by naphthyl and anthryl units to form a homologous series of structures. The 2,6 attachment of the vinylene linkage on the anthryl ring provides novel structures that have not been reported before due to their synthetic inaccessibility. The introduction of naphthyl units results in a hypsochromatic shift in the absorption and emission spectra, while the introduction of anthryl units leads to a bathochromatic shift relative to the naphthalene structures. The observed structural variation of the spectroscopic properties …


Time-Temperature And Relative Humidity Profiles Of Chilled And Frozen Foods In Retail Outlets Nationwide, And Evaluation Of Related Practices, Caroline Garvan Jan 2007

Time-Temperature And Relative Humidity Profiles Of Chilled And Frozen Foods In Retail Outlets Nationwide, And Evaluation Of Related Practices, Caroline Garvan

Masters

Temperature abuse combined with poor operational practices are the dominant factors in the mishandling of food products which can result in outbreaks of food borne disease. The objective of this work was to determine efficacy of temperature and relative humidity control using recorded data and to assess the food safety management systems in operation in retail outlets in the Republic of Ireland. This study also aims to examine food safety risk to consumers as a result of inadequate temperature control and poor food hygiene practices using microbial analysis and predictive modelling. External air temperature, core temperature and relative humidity of …


Averaging Of The Electron Effective Mass In Multicomponent Transparent Conducting Oxides, Julia E. Medvedeva Jan 2007

Averaging Of The Electron Effective Mass In Multicomponent Transparent Conducting Oxides, Julia E. Medvedeva

Physics Faculty Research & Creative Works

We find that layered materials composed of various oxides of cations with s2 electronic configuration, XY2O4, X = in or Sc, Y = Ga, Zn, Al, Cd and/or Mg, exhibit isotropic electron effective mass which can be obtained via averaging over those of the corresponding single-cation oxide constituents. This effect is due to a hybrid nature of the conduction band formed from the s-states of all cations and the oxygen p-states. Moreover, the observed insensitivity of the electron effective mass to the oxygen coordination and to the distortions in the cation-oxygen chains suggests that a …


Optimization Of Optical Tweezers, Matthew Knecht Jan 2007

Optimization Of Optical Tweezers, Matthew Knecht

Capstone Research Projects

Recently our group demonstrated the ability to trap bacteria using optical tweezers, but low laser power limited trapping ability. I will report on improvements made to both laser power and beam quality, which lead to improved trapping ability. Initial results were seen to increase laser intensity at the sample, but the beam quality was severely degraded. The solution to this problem was to better shape the laser beam using an anamorphic prism pair. This process was repeated for a higher power laser diode. We were able to maintain a high quality beam while more than doubling laser power at the …


Eliciting Software Requirements For Elementary Keyboarding Instruction, Mark A. Eirich Jan 2007

Eliciting Software Requirements For Elementary Keyboarding Instruction, Mark A. Eirich

Capstone Research Projects

This Southern Scholars research project developed requirements for keyboarding instruction software to be used in the elementary classroom. The project was undertaken on the premise that the teachers in the Georgia-Cumberland Conference1 are not satisfied with any currently existing keyboarding instruction software, and that software better suited to the classroom could be designed. Methods used to gather data included: a literature review on keyboarding instruction methods, a summary review of existing keyboarding software interviews with teachers and school staff, and a survey of elementary teachers to evaluate their current situation and identify the software features they consider most important. These …


Purification And Study Of Phosphoglucose Isomerase In Cauliflower, Shanti Shrestha Jan 2007

Purification And Study Of Phosphoglucose Isomerase In Cauliflower, Shanti Shrestha

Capstone Research Projects

Phosphoglucose isomerase (PGI), an important enzyme in the glycolytic pathway, catalyzes the conversion of glucose-6-phosphate to fructose-6-phosphate and vice versa. The purpose of this research was to isolate PGI from cauliflower using a shortened procedure through column chromatography and characterize it through absorbance readings, enzyme activity measurements, and SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis). PGI was successfully isolated from cauliflower using ion-exchange chromatography. Absorbance and enzyme activity were determined at 280nm and 340nm respectively. There appeared to be one main absorbance peak for the protein at fraction 31, as well as a maximum peak for enzyme activity. SDS-PAGE was conducted …


Native Communities And Climate Change: Protecting Tribal Resources As Part Of National Climate Policy: Executive Summary, Jonathan M. Hanna, University Of Colorado Boulder. Natural Resources Law Center, Western Water Assessment (Program) Jan 2007

Native Communities And Climate Change: Protecting Tribal Resources As Part Of National Climate Policy: Executive Summary, Jonathan M. Hanna, University Of Colorado Boulder. Natural Resources Law Center, Western Water Assessment (Program)

Books, Reports, and Studies

7 p. : col. ill., maps


Modelling Of Re-Absorption Losses In Quantum Dot Solar Concentrators, Manus Kennedy Jan 2007

Modelling Of Re-Absorption Losses In Quantum Dot Solar Concentrators, Manus Kennedy

Conference Papers

A Monte-Carlo ray-trace model has been developed which allows the calculation of the optical efficiency (ηopt) and concentration ratio (CR) values of a Quantum Dot Solar Concentrator (QDSC). In this paper, ηopt values have been calculated using a range of material refractive indices, material attenuation coefficients, and quantum dot (QD) quantum efficiencies (QE). Spectral overlap leads to reabsorption of light in the device which leads to increased escape cone losses and QD QE losses. Results have been obtained for ideal QD spectra, where there is 0% overlap between QD emission and absorption spectra (and hence no re-absorption), and for real …


Destination Website Effectiveness – A Delphi-Based Emetric Approach – A Dms Perspective, Patrick Horan, Andrew Frew Jan 2007

Destination Website Effectiveness – A Delphi-Based Emetric Approach – A Dms Perspective, Patrick Horan, Andrew Frew

Conference papers

This paper outlines the development and evaluation of a comprehensive set of eMetrics for measuring the effectiveness of a Destination Management Systems’ (DMS) websites from the perspective of small and medium-sized hotel enterprises. Ultimately, from a hotel’s viewpoint, website effectiveness depends on how well a site performs with respect to the related business goals. The priority of the research is thus to establish which criteria are important for destination websites and to determine a mechanism for their measurement. These criteria are divided into both macro- and micro- level metrics which each combine to provide information that is actionable from a …


Contracts Database: Part Of The Solution, Michael J. Caprioli Jan 2007

Contracts Database: Part Of The Solution, Michael J. Caprioli

Regis University Student Publications (comprehensive collection)

This document reviews the results of the implementation and aftermath of the Contracts Database, a 3 tier system using Java technology. Executive management at Intercontinental Research Foundation (IRF) decided to create a line of web applications for the research analysts to use as tools and create some consistency in the business process. The Contracts Database would be the first product in this initiative. This application would serve as an online database to be incorporated into the research analyst's daily routine. This document demonstrates the successful development of a web application and the potential pitfalls of trying to change business methodology.


Improved Parameterization To Invert Rayleigh-Wave Data For Shallow Profiles Containing Stiff Inclusions, Carlos Calderon-Macias, Barbara Luke Jan 2007

Improved Parameterization To Invert Rayleigh-Wave Data For Shallow Profiles Containing Stiff Inclusions, Carlos Calderon-Macias, Barbara Luke

Civil and Environmental Engineering and Construction Faculty Research

Inversion of shear-wave velocity profiles from phase-velocity measurements of Rayleigh-wave energy for sites containing stiff layers can be erroneous if such layers are not characterized in the starting or reference model. Incorporation of a priori knowledge then is key for converging upon a realistic or meaningful solution. Resolving soil profiles in desert regions where stiff layers cemented with calcium carbonate are intermixed with softer, uncemented media is an application for which locating shallow stiff inclusions has important implications. Identification of the stiff layers is critical for foundation design and cost estimating of excavations. A parameterization that seems adequate for this …


Response Of Eelgrass Zostera Marina To Co2 Enrichment: Possible Impacts Of Climate Change And Potential For Remediation Of Coastal Habitats, Sherry L. Palacios, Richard C. Zimmerman Jan 2007

Response Of Eelgrass Zostera Marina To Co2 Enrichment: Possible Impacts Of Climate Change And Potential For Remediation Of Coastal Habitats, Sherry L. Palacios, Richard C. Zimmerman

OES Faculty Publications

Projected increases in dissolved aqueous concentrations of carbon dioxide [CO2(aq)] may have significant impacts on photosynthesis Of CO2-limited organisms such as seagrasses. Short-term CO2(aq) enrichment increases photosynthetic rates and reduces light requirements for growth and survival of individual eelgrass Zostera marina L. shoots growing in the laboratory under artificial light regimes for at least 45 d. This study examined the effects of long-term CO2(aq) enrichment on the performance of eelgrass growing under natural light-replete (33% surface irradiance) and light-limited (5% surface irradiance) conditions for a period of 1 yr. Eelgrass shoots were grown at …


Antibacterial Fluoromicas: A Novel Delivery Medium, Bekir Dizman, Jonathan C. Badger, Mohamed O. Elasri, Lon J. Mathias Jan 2007

Antibacterial Fluoromicas: A Novel Delivery Medium, Bekir Dizman, Jonathan C. Badger, Mohamed O. Elasri, Lon J. Mathias

Faculty Publications

Antibacterial fluoromicas were prepared by ion-exchanging fluoromicas with different antibacterial agents including various quaternary ammonium compounds, AgNO3, and norfloxacin. Antibacterial activities of the ion-exchanged fluoromicas were determined against Staphylococcus aureus and Escherichia coli. Minimum inhibitory concentration (MIC) and zone of inhibition (ZOI) tests were performed to determine both antibacterial effectiveness and mode of action associated with the fluoromicas. All treated fluoromicas showed excellent antibacterial activities against both types of bacteria. The antibacterial activities of treated fluoromicas were found to be either better than or the same as those of neat antibacterial agents. The repeated antibacterial activity tests demonstrated …


Shelf Sediment Dispersal Mechanisms And Deposition On The Waiapu River Shelf, New Zealand, Tara A. Kniskern Jan 2007

Shelf Sediment Dispersal Mechanisms And Deposition On The Waiapu River Shelf, New Zealand, Tara A. Kniskern

Dissertations, Theses, and Masters Projects

The Waiapu River, located on the North Island of New Zealand, drains a small catchment and has one of the highest sediment yields in the world. The river delivers most of its annual sediment load during floods into energetic coastal waters. These conditions are favorable for producing multiple sediment transport mechanisms, including transport in positively and negatively buoyant freshwater plumes, gravitydriven flows, and resuspension. Analyses of Waiapu River shelf seabed data showed that multiple transport mechanisms influence strata formation. Fluvial sediments are initially deposited at water depths shallower than 80 m before being remobilized and deposited at greater water depths. …


Hypoxia And Macoma Balthica: Ecological Effects On A Key Infaunal Benthic Species, William Christopher Long Jan 2007

Hypoxia And Macoma Balthica: Ecological Effects On A Key Infaunal Benthic Species, William Christopher Long

Dissertations, Theses, and Masters Projects

Hypoxia, low dissolved oxygen, is an important environmental stressor in estuarine systems. In this dissertation, I examine the effects of hypoxia on the macrobenthic communities of the York and Rappahannock Rivers, Chesapeake Bay, USA, and in particular its effects on the infaunal clam Macoma balthica. A survey of the macrobenthic community was performed using box-coring before and after hypoxia in 2003 and 2004 in both rivers. Hypoxia was associated with a change in the macrobenthic community towards smaller, shorter-lived, opportunistic species; and a substantial decrease in biomass. M. balthica recruited into all areas of the river but suffered local extinction …


Carbon Dioxide In The Atmosphere, Storm Project Jan 2007

Carbon Dioxide In The Atmosphere, Storm Project

Open Educational Resources

Objectives: Students learn the importance of carbon dioxide in the atmosphere.

National Science Education Standards: As a result of activities in grades 9-12, all students should develop abilities necessary to do scientific inquiry and understandings about scientific inquiry. As a result of their activities in grades 9-12, all students should develop understanding of matter, energy, and organization in living systems. As a result of their activities in grades 9-12, all students should develop an understanding of energy in the earth system and geochemical cycles.


Understanding Dispersion Models Using Computer Technology, Storm Project Jan 2007

Understanding Dispersion Models Using Computer Technology, Storm Project

Open Educational Resources

Objectives:

  • Analyze dispersion models
  • Use computer models to predict outcomes of various scenarios

9-12 NSES Standards:

  • Standard A: Inquiry - Abilities necessary to do scientific inquiry and Understanding about scientific inquiry
  • Standard E: Science and Technology - Abilities of technological design and Understanding about science and technology
  • Standard F: Science in Personal and Social Perspectives - Personal and community health, Population growth, Natural resources, Environmental quality, Natural and human-induced hazards, Science and technology in local, national, and global challenges


Indoor Air Pollution, Storm Project Jan 2007

Indoor Air Pollution, Storm Project

Open Educational Resources

Objectives: Students will learn about indoor air pollutants the types and legal concentrations and affects on human health. The students will also determine the pathway for the formation of radon.

National Science Education Standards: As a result of their activities in grades 9-12, all students should develop an understanding of the structure of the atoms; environmental quality; and natural and human-induced hazards.

As a result of their activity the students will have a better understanding of the atom’s parts and how the atom disintegrates and interacts with the environment. The students should have a better understanding of the …


Oxygen Give And Take, Storm Project Jan 2007

Oxygen Give And Take, Storm Project

Open Educational Resources

Summary: This is a series of three activities followed by a worksheet. The concepts taught include gas production (O2 and CO2), chemical reactions, catalysts, and pollution caused by combustion. Correlation to National Science Education Standards

  • Content Standard 9-12 Physical Science B Chemical Reactions
Chemical reactions may release or consume energy. Some reactions such as the burning of fossil fuels release large amounts of energy by losing heat and by emitting light.
  • Content Standard 9-12 Earth and Space Science D Geochemical Cycles
The earth is a system containing essentially a fixed amount of each stable chemical atom or element. Each element …


There's A Whole Lotta Spillin' Goin' On!, Storm Project Jan 2007

There's A Whole Lotta Spillin' Goin' On!, Storm Project

Open Educational Resources

Unit Learning Objectives: The learner should be able to:

1. Compare and contrast hazardous chemical spills 2. Comprehend how hazardous chemicals affect the environment.
3. Explain the difficulty involved in cleaning up a hazardous spill.
4. Explain how the chemical travels once it is released.
5. Assess how hazardous chemicals affect the human body and animal life.
6. Analyze a chemical spill and its affects on its surroundings.
7. Create an emergency management system based on a real life situation

Evidence of Understanding: By the end of this unit, students should be able to demonstrate a clear understanding of hazardous …