Physical Sciences and Mathematics Commons^™

Influence Of Varying Intensities Of Natural Area On-Site Interpretation On Attitudes And Knowledge, Michael Hughes

Theses

Using interpretation as a means of influencing attitudes and knowledge is a core component of natural area management practice. However, this aspect of on-site interpretation is rarely assessed when evaluating natural area management success. This thesis examined the immediate influence of different intensities of on-site interpretation on attitudes and knowledge of visitors to natural areas. Measuring the immediate (short term) influence of a site experience enables clearer links to be made between survey responses and interpretation used at a specific site, something long term surveys are less able to achieve. Two sites from Western Australia (the Tree Top Walk and …

Effects Of Irrigation Water Salinity On Forage Growth And Qualities Of Some Salt Tolerant Species Under Uae Conditions, Mahmood Abdul Razaq Belselah

Theses

Experiments were conducted at the International Center for Bio saline Agriculture (ICBA) in Dubai to evaluate the growth and productivity of some locally grown grass species; Rhodes grass (Chloris gayana L.) var. Katambora, Pioneer, and Callide; and Panicum grass (Panicum maximum) var. Green, and Gatton over a range of irrigation levels (1 gal/hr and 1.3 gal/hr), and water salinity (5 dS/m, 10 dS/m and 15 dS/m). The effect of different quality of water in respect to the salinity levels would provide information about water use efficiencies and soil salinity over a period. Growth and biomass productivity of …

Laboratory Investigation Of Transport And Treatment Of Chromium In Groundwater At Liwa District, Abu Dhabi, Wali-Ur-Rahman Din Badshah

Theses

Groundwater quality is a critical aspect affecting utilization of this source for certain purposes. In the UAE, utilization of groundwater for domestic purposes is well practiced. While the quality of groundwater at some locations does not permit direct utilization of this source, groundwater, in many cases, is mixed with desalinated water at certain proportion before being disinfected and then distributed to customers.

Groundwater of Liwa aquifer contains high level of Cr(VI) which is believed to originate from natural sources. However, little has been done to investigate the fate of this contaminant. Spreading of chromium to nearby aquifers may render the …

Assessment Of Brine Shrimp (Artemia Sp.) Productivity At Al Wathba Wetland Reserve, Abu Dhabi (Uae), Shaikha Salem Obaid Al Dhaheri

Theses

Al Wathba Lake was created in 1982 by accidental discharge of over-capacity treated sewage water from Al Mafraq Waste Water Treatment Plant (WWT). The lake lies on the north side of the Abu Dhabi - Al Ain truck road, approximately 40 km Southeast of Abu Dhabi Island. In 1998, the lake and its surroundings were designated as protected area, the Al Wathba Wetland Reserve, and placed under the management of the Environmental Research and Wildlife Development Agency (ERWDA). The reserve covers an area of approximately 5 km², and the lake system covers an area of 1.5 km^{2 …}

Geological Assessment Of The Intertidal Environment In Some Areas Along The Arabian Gulf And Gulf Of Oman Coastal Region, Uae: A Comparative Study., Mouza Rashid Mohamed Airashidi

Theses

The present study aims at assessing the geological environment of some selected areas along the coastal zones of the Arabian Gulf (northern coast) and the Gulf of Oman (eastern coast). Eight stations were selected for this study; these include three stations from the Gulf of Oman (Khor Fakkan, Kalba and Fujairah) and five stations from the Arabian Gulf (Dubai, Sharjah, Ajman, Umm Al-Quwen and Ras A1-Khaimah). 25 sediment samples were collected and subjected to grain-size analysis, X-ray diffraction analysis, microfacies and petrographic study and chemical analysis. Shell samples were collected from the same sites using 50x50x10 cm box. These shells …

Insect Control Using Chitinolytic Soil Actinomycetes As Biocontrol Agents, Fatma Khamis Al-Kaabi

Theses

No abstract provided.

The Role Of Environmental Impact Assessment In The Urban Development Process Case Study: Dubai, Uae, Abdulrahman Mohammed Al Sharid

Theses

With no doubt the Urban & Economic Development should persist in Dubai with same current rates to sustain prosperous living conditions for the inhabitants of the Emirate. These rates have exceeded the International rates in some aspects specially those related to Urban Sprawl and Power Consumption, Telecommunication Services, etc.

To insure the continuity of this economic growth, a balance should be established between consumption rates and natural component depletion. To achieve this balance, certain criteria and regulations should occur focusing on Environmental Balance and Environmental Impact Assessment which consider all permutable aspects. So as to avoid multiple negative effects in …

Investigation Of Implementation Techniques For Backpropagation Neural Networks., John Culloty

Theses

Artificial neural networks are biologically inspired computational methods that have the ability to approximate discrete, real and vector valued target functions. For some problem domains this ability makes neural networks a more appealing solution than traditional computational techniques. Such problem domains typically contain a large number of parameters that are interrelated in a complex and often unknown manner. This makes rule based solutions all but impossible. However another feature of such problem domains is the presence of large volumes of real world data that can be used to tram a neural network until it learns the solution.

One of the …

A Proposal To Meet The Biofuels Directive In Ireland, Karl Mccarthy

Theses

In 1990 the transport sector accounted for 9,5% of all Irish emissions. By 2010 it is predicted that transport emissions will have increased by 179%, accounting for 18.8% of all emissions. It is predicted that transport emissions will therefore be around 14,000 kt in 2010. This equates to around €370 million pa in carbon taxes if and when the taxation regime is introduced. This €370 million may be used to facilitate a biofuel industry (for example, by reducing excise duty on biofuels).

The proposed carbon tax along with the EU Biofuels Directive aims to encourage the use of renewable transport …

Integrating Experiments And Simulators Into A Distributed E-Learning Environment, Frank Koehler

Theses

New information and communication technologies have emerged in the last few years which have made an impact on learning at all levels. At universities, the spectrum of learning support ranges from enriching traditional lectures and courses with multi- media elements to complete web-based interactive learning environments. A special aspect based on the new media technologies is learning within model worlds by use of simulations or real-life experiments. There are normally no links between these applications and the learning content, so it is impossible to tap the full potential of these applications. Research activities in the area of e-learning underline the …

Environment Friendly Organic Synthesis, Russell C. Smith '04

Honors Projects

In recent years, chemists have increasingly focused on environment friendly approaches to organic chemistry. By practicing Green Chemistry, chemists are attempting to reduce the use of hazardous materials and minimize waste. Green chemistry, which involves the design and some times redesign of chemical syntheses that are more environmentally friendly, attempts to lower risk by using inherently less toxic or non-toxic reagents.

The goal of this research was to (1) investigate the use of bismuth triflate as a catalyst for resorcinarene formation as well as the synthesis of homoallyl ethers and (2) to investigate the utility of ionic liquids as solvents …

On Multivariate Abel-Gontscharoff Interpolation, Tian-Xiao He

Scholarship

By using Gould's annihilation coefficients, we obtain an explicit fundamental polynomials of Multivariate Abel-Gontscharoff Interpolation and its remainder expression.

Investigation Of The Photoinduced Surface Relief Modulation In Acrylamide-Based Photopolymer, Izabela Naydenova, Emilia Mihaylova, Suzanne Martin, Vincent Toal

Conference Papers

A surface relief diffraction grating is inscribed in acrylamide photopolymer by holographic recording with spatial frequency below 300 l/mm. The periodic surface modulation appears in addition to a volume phase holographic grating. Due to the nature of the presented photopolymerisable material the gratings are induced by light only and no post-processing is required. An investigation of the dependance of the amplitude of the photoinduced relief modulation on spatial frequency of recording and on sample thickness has been carried out utilising white light interferometry. A model of the mechanism of surface relief formation is proposed on the basis of the measured …

On-Road Motor Vehicle Emissions From Around The World, Donald H. Stedman, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

In 1993, on-road emissions in Continental Europe showed a pronounced South/North declining gradient for CO, HC and NO fuel specific emissions (gm/kg). Emissions in Hamburg and Rotterdam were comparable to emissions measured in 1993 in the U.S.A. with the same on-road instrument. Contrasts between emissions in the USA, the UK and Sweden demonstrated the importance both of modern catalysts and of good maintenance. The same contrast in 1998 shows the same picture but lower emissions at all three locations. In the decade from 1993-2003, U.S. emissions have declined markedly, apparently mainly as a result of lower emitting, better maintained, new …

An Agent-Based Approach To Adaptive Navigational Support Within 3d-Environments, Bianca Schoen-Phelan, Gregory O'Hare, Brian Duffy, Alan Martin

Conference papers

his paper investigates mechanisms and approaches to assisting user navigation and exploration within 3-dimensional worlds. Specifically it advocates the deployment of an agentbased approach to dynamic system assistance and intervention. A performance equation is presented in a basic and an extended version, which is used to activate system interventions and to evaluate user performances online and offline. The measure is derived via a light-weight computationally inexpensive masking approach. We describe some navigation experiments and the results of navigational intervention via the damping of the sensitivity of the navigational keys. Interestingly the navigational assistance does not yield improvements in the subjects’ …

Spectroscopic Investigation Of Nitrogenase: Epr And Mcd Studies Of The Femo Cofactor And The P-Cluster, Robyn B. Broach

LSU Doctoral Dissertations

Little is known about substrate binding and reduction of nitrogenase. EPR spectroscopy is used here to observe intermediate states generated by different substrates. Two different spin states (S=3/2 and S=1/2) were exhibited for each substrate, which may result from different binding of the substrate to the cofactor (side-on or terminal binding) or the difference of the substrate binding to either Fe or Mo of the cofactor. Parallel studies were performed on a variant MoFe protein, alpha-195^Gln, which exhibited different signals from the wild-type suggesting that the substituted amino acid maybe necessary to reach some mechanistic states that the …

Virtual Personal Assistants In A Pervasive Computing World, John F. Bradley, Brian R. Duffy, Gregory O'Hare, Alan Martin, Bianca Schoen-Phelan

Conference papers

Computing paradigms are constantly evolving-from mainframe to desktop, and on to ubiquitous computing. With a wide variety of devices, each with varying constraints, it would be quite difficult to develop services that would operate in a uniform manner across all platforms. With this in mind we offer an agent based solution. Agent attributes of autonomy, adaptability and mobility make them highly suitable for use in pervasive computing environments. Agent Chameleons illustrates a framework for Virtual Personal Assistants (VPA) for the information age. This paper briefly outlines some of the technologies and concepts that underpin the functionality of a VPA.

An Analysis Of Case-Base Editing In A Spam Filtering Systems, Sarah Jane Delany, Padraig Cunningham

Conference papers

Because of the changing nature of spam, a spam filtering system that uses machine learning will need to be dynamic. This suggests that a case-based (memory-based) approach may work well. Case-Based Reasoning (CBR) is a lazy approach to machine learning where induction is delayed to run time. This means that the case base can be updated continuously and new training data is immediately available to the induction process. In this paper we present a detailed description of such a system called ECUE and evaluate design decisions concerning the case representation. We compare its performance with an alternative system that uses …

An Assessment Of Case Base Reasoning For Short Text Message Classification, Matt Healy, Sarah Jane Delany, Anton Zamolotskikh

Conference papers

Message classification is a text classification task that has provoked much interest in machine learning. One aspect of message classification that presents a particular challenge is the classification of short text messages. This paper presents an assessment of applying a case based approach that was developed for long text messages (specifically spam filtering) to short text messages. The evaluation involves determining the most appropriate feature types and feature representation for short text messages and then comparing the performance of the case-based classifier with both a Naıve Bayes classifier and a Support Vector Machine. Our evaluation shows that short text messages …

Analytical Separations Using Packed And Open-Tubular Capillary Electrochromatography, Constantina P. Kapnissi

LSU Doctoral Dissertations

The goal of the research reported in this dissertation is to develop packed and open-tubular capillary electrochromatographic methods for improved achiral and chiral separations of various classes of analytes. The first part of this research involves the separation of seven benzodiazepines by the use of the packed mode of capillary electrochromatography (CEC) and a 40 cm packed bed of Reliasil 3 μm C₁₈ stationary phase. Optimal conditions were established by varying the mobile phase, the amount of organic modifier, the buffer concentration, the applied voltage, and the column temperature. The second part of this research focuses on the open-tubular …

Progress At The Heidelberg Ebit, Jose R. Crespo Lopez-Urrutia, Jean Pierre Braun, Gunter Brenner, Hjalmar Bruhns, Christina Dimopoulou, I. N. Draganic, Daniel Fischer, Antonio J. Gonzalez, A. Lapierre, V. Mironov, Robert Moshammer, R. Soria Orts, Hiroyuki Tawara, M. Trinczek, Joachim Hermann Ullrich

Physics Faculty Research & Creative Works

Two years after the relocation of the Heidelberg EBIT, several experiments are already in operation. Spectroscopic measurements in the optical region have delivered the most precise reported wavelengths for highly charged ions, in the case of the forbidden transitions of Ar XIV and Ar XV. The lifetimes of the metastable levels involved in those transitions has been determined with an error of less than 0.2%. A new, fully automatized x-ray crystal spectrometer allows systematic measurements with very high precision and reproducibility. Absolute measurements of the Lyman series of H-like ions are currently underway. Dielectronic recombination studies have yielded information on …

Renormalization-Group Analysis Of The Generalized Sine-Gordon Model And Of The Coulomb Gas For D > 3 Dimensions, I. Nandori, Ulrich D. Jentschura, Kornel Sailer, Gerhard Soff

Physics Faculty Research & Creative Works

Renormalization-group (RG) flow equations have been derived for the generalized sine-Gordon model (GSGM) and the Coulomb gas (CG) in d ≥ 3 of dimensions by means of the Wegner-Houghton method, and by way of the real-space RG approach. The UV scaling laws determined by the leading-order terms of the flow equations are in qualitative agreement for all dimensions d ≥ 3, independent of the dimensionality, and in sharp contrast to the special case d=2. For the 4-dimensional GSGM it is demonstrated explicitly (by numerical calculations) that the blocked potential tends to a constant effective potential in the infrared limit, satisfying …

Effects Of Localization And Amplification On Intensity Distribution Of Light Transmitted Through Random Media, Alexey Yamilov, Hui Cao

Physics Faculty Research & Creative Works

We numerically study the statistical distribution of intensity of light transmitted through quasi-one-dimensional random media by varying the dimensionless conductance g and the amount of absorption or gain. A markedly non-Rayleigh distribution is found to be well fitted by the analytical formula of Nieuwenhuizen et al. [Phys. Rev. Lett. 74, 2674 (1995)] with a single parameter g′ . We show that in the passive random system g′ is uniquely related to g , while in amplifying or absorbing random media g′ also depends on the gain or absorption coefficient.

Highest-Quality Modes In Disordered Photonic Crystals, Alexey Yamilov, Hui Cao

Physics Faculty Research & Creative Works

We studied the modes of the highest-quality factor Qm in disordered photonic crystals. by varying the strength of disorder, we identified five different scaling regimes of the ensemble averaged (Qm) with the system size. For sufficiently large systems, (Qm) reaches the maximum at some finite degree of disorder, where its value is comparable to the quality factor of an intentionally introduced single defect at the center of a photonic band gap. Near this optimal degree of disorder, we predict a superexponential increase of (Qm) with the system size, due to migration of the frequencies of the highest-quality modes toward the …

Kinetics Of Binary Nucleation Of Vapors In Size And Composition Space, Sergey P. Fisenko, Gerald Wilemski

Physics Faculty Research & Creative Works

We reformulate the kinetic description of binary nucleation in the gas phase using two natural independent variables: the total number of molecules g and the molar composition x of the cluster. The resulting kinetic equation can be viewed as a two-dimensional Fokker-Planck equation describing the simultaneous Brownian motion of the clusters in size and composition space. Explicit expressions for the Brownian diffusion coefficients in cluster size and composition space are obtained. For characterization of binary nucleation in gases three criteria are established. These criteria establish the relative importance of the rate processes in cluster size and composition space for different …

Order-Parameter Symmetry And Mode-Coupling Effects At Dirty Superconducting Quantum Phase Transitions, Rastko Sknepnek, Thomas Vojta, Rajesh Narayanan

Physics Faculty Research & Creative Works

We derive an order-parameter field theory for a quantum phase transition between a disordered metal and an exotic (non- s -wave) superconductor. Mode coupling effects between the order parameter and other fermionic soft modes lead to an effective long-range interaction between the anomalous density fluctuations which is reflected in singularities in the free energy functional. However, this long-range interaction is not strong enough to suppress disorder fluctuations. The asymptotic critical region is characterized by run-away flow to large disorder. For weak coupling, this asymptotic region is very narrow. It is preempted by a wide crossover regime with mean-field critical behavior …

Smeared Phase Transition In A Three-Dimensional Ising Model With Planar Defects: Monte Carlo Simulations, Rastko Sknepnek, Thomas Vojta

Physics Faculty Research & Creative Works

We present results of large-scale Monte Carlo simulations for a three-dimensional Ising model with short-range interactions and planar defects, i.e., disorder perfectly correlated in two dimensions. We show that the phase transition in this system is smeared, i.e., there is no single critical temperature, but different parts of the system order at different temperatures. This is caused by effects similar to but stronger than Griffiths phenomena. In an infinite-size sample there is an exponentially small but finite probability to find an arbitrary large region devoid of impurities. Such a rare region can develop true long-range order while the bulk system …

Study Of Structural And Magnetic Properties Of Iron-Rich Mixed Rare-Earth Nddyfe (17-Y-X)Coxsiy Compounds, Kishore Kamaraju, Jinbo Yang, William B. Yelon, Oran Allan Pringle, M. S. Kim, Qingsheng Cai, William Joseph James

Physics Faculty Research & Creative Works

A series of NdDyFe(17-y-x)CoxSiy solid solutions with = 2 and 3 and = 0.5 1.0 and 1.5 were prepared by induction melting stoichiometric amounts of high-purity elements. The postannealed samples consist of two phases belonging to the space groups R3 m and P63 mmc . The lattice parameters and the unit cell volumes were calculated from the refinements of the magnetic and structural unit cells using the FULLPROF version of the Rietveld program. For a fixed content of Co, the maximum Curie temperatures (305 C to 405 C) were observed in samples with = 1 and having two phases, a …

Traversal Times For Random Walks On Small-World Networks, V. M. Kenkre, Paul Ernest Parris

Physics Faculty Research & Creative Works

We study the mean traversal time tau for a class of random walks on Newman-Watts small-world networks, in which steps around the edge of the network occur with a transition rate F that is different from the rate f for steps across small-world connections. when f>>F, the mean time tau to traverse the network exhibits a transition associated with percolation of the random graph (i.e., small-world) part of the network, and a collapse of the data onto a universal curve. This transition was not observed in earlier studies in which equal transition rates were assumed for all allowed steps. …

Ultraviolet Photonic Crystal Laser, Alexey Yamilov, Hui Cao, Robert P. H. Chang, Xiaohua Wu, Xang Liu, Shuyou Li, Vinayak P. Dravid

Physics Faculty Research & Creative Works

We fabricated two-dimensional photonic crystal structures in zinc oxide films with focused-ion-beam etching. Lasing is realized in the near-ultraviolet frequency at room temperature under optical pumping. From the measurement of lasing frequency and spatial profile of the lasing modes, as well as the photonic band structure calculation, we conclude that lasing occurs in the strongly localized defect modes near the edges of photonic band gap. These defect modes originate from the structure disorder unintentionally introduced during the fabrication process. ©2004 American Institute of Physics