Physical Sciences and Mathematics Commons^™

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 …

Transport Of Pesticides Through Soil Columns From Al-Ain Area, United Arab Emirates, Huda Ateeq Al Hassani

Theses

Proper management of pesticides application in the UAE is greatly lacking, causing waste of resources and environmental concerns due to the excessive use of these chemicals. It has been reported that the rate of pesticides use in UAE reaches about 10 kg/hectare/yr, posing a potential threat to the quality of water in underlying aquifers. Little, however, is known about the mobility of applied pesticides in the UAE subsurface environment and the impact of these pesticides on soil and groundwater quality.

The aim of this study was to gain an understanding of the fate and mobility of pesticides in the UAE …

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

Theses

No abstract provided.

Satellite Evidence Of Hurricane-Induced Phytoplankton Blooms In An Oceanic Desert, S. M. Babin, J. A. Carton, T. D. Dickey, J. D. Wiggert

CCPO Publications

The physical effects of hurricanes include deepening of the mixed layer and decreasing of the sea surface temperature in response to entrainment, curl-induced upwelling, and increased upper ocean cooling. However, the biological effects of hurricanes remain relatively unexplored. In this paper, we examine the passages of 13 hurricanes through the Sargasso Sea region of the North Atlantic during the years 1998 through 2001. Remotely sensed ocean color shows increased concentrations of surface chlorophyll within the cool wakes of the hurricanes, apparently in response to the injection of nutrients and/or biogenic pigments into the oligotrophic surface waters. This increase in post-storm …

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 …

Impacts Of The Alien Invasive Prosopis Juliflora (Swartz) Dc. On The Flora And Soils Of The Uae And Feasibility Of Using It In The Afforestation Of Saline Habitats, Awatif Abdulleh Khalfan Al-Rawai

Theses

The effects of the invasive exotic Prosopis juliflora shrubs on the natural plant communities were assessed in three regions (Sharja, Ras Al-Khima and Fujira) of the UAE. The effect of the P. juliflora shrubs on the associated annual and perennial plants was studied in a number of quadrats distributed under, at the margin and outside the crown of a shrub. The results indicate that the effect of P. juliflora on the associated species depends significantly on the density and size of their individuals. Large individuals and greater densities have significantly adverse effect on the associated species. All of the studied …

First-Principles Study Of Magnetism In (112̄0) Zn1−Xmnxo Thin Film, Q. Wang, Puru Jena

Physics Publications

First-principles calculations of total energies and magnetism of Zn1−xMnxOthin film are performed by simulating it with a slab consisting of seven layers along (112̄0). It is shown that a single Mn atom shows very little preference for the site it occupies. This is consistent with the experimental finding that Mn atoms are homogeneously distributed in ZnO films. As the concentration of Mn atoms increases, antiferromagnetic coupling between Mn atoms becomes more favorable, and there is a tendency for Mn atoms to form clusters around oxygen, in agreement with recent experiments.

Metastability Of A Gold Nanoring: Density-Functional Calculations, Q. Sun, Q. Wang, Puru Jena, R. Note, J-Z. Yu, Y. Kawazoe

Physics Publications

First-principles calculations based on gradient corrected density functional theory show that a cluster of as few as 90 gold atoms can be stabilized in a ring structure having fcc (111) motif with the binding energy/atom and interatomic distance approaching 91% and 96% of the bulk values, respectively. Although the ring structure lies 0.139eV/atom higher in energy than a polyicosahedral structure, the calculated frequencies are real. Thus under appropriate experimental conditions it may still be possible to synthesize a metastable form of gold nanoring, as found in the recent experiment.

Carrier-Mediated Ferromagnetism In N Codoped (Zn,Mn)O (101¯0) Thin Films, Q. Wang, Q. Sun, Puru Jena, Y. Kawazoe

Physics Publications

Using first principles calculations based on the density functional theory and generalized gradient approximation we show that the ground state of Mn doped ZnO (101¯0) thin film changes from antiferromagnetic to ferromagnetic when codoped with N. The ferromagnetic coupling between Mn spins arises due to the overlap between N 2p and Mn 3d electrons in the spin up band, rendering the system half-metallic character.

Hydrogen Adsorption And Magnetic Behavior Of Fen And Con Clusters: Controlling The Magnetic Moment And Anisotropy One Atom At A Time, N. O. Jones, M. R. Beltran, Shiv N. Khanna, T. Baruah, M. R. Pederson

Physics Publications

Theoretical studies to investigate the effect of H absorption on the magnetic moment of small Fen and Con clusters have been carried out using gradient corrected density-functional approach. Our studies on clusters containing up to four transition metal and 2 H atoms show that the successive addition of H atoms can lead to monotonic or oscillatory change from the free cluster magnetic moment. A detailed analysis of the density of electronic states shows that the variations in the magnetic moment can be related to the location of the lowest unoccupied molecular orbital in the parent cluster. It is shown that …

Ferromagnetism In Cr-Doped Gan: A First-Principles Calculation, G. P. Das, B. K. Rao, Puru Jena

Physics Publications

Electronic structure, energy bands, and magnetic properties of Cr-doped GaN have been calculated from first principles using a 32 atom supercell within the frame work of linearized muffin-tin orbital tight binding method and gradient-corrected density-functional theory. The coupling between Cr atoms is found to be ferromagnetic with a magnetic moment of 2.69μB at each Cr site. The magnetic moments of Ga and N sites are rather small, namely, 0.025μB and −0.025μB, respectively, yielding a total moment of 6μB per supercell. Parallel calculations done on small clusters of Cr-doped GaN also yield similar results indicating that magnetic coupling between Cr atoms …

South Florida Coastal Water Quality Monitoring Network Fy2004 Cumulative Report To The South Florida Water Management District (Contract No. C-15397), Joseph N. Boyer

SERC Research Reports

No abstract provided.

Coalgebras And Modal Expansions Of Logics, Alexander Kurz, Alessandra Palmigiano

Engineering Faculty Articles and Research

In this paper we construct a setting in which the question of when a logic supports a classical modal expansion can be made precise. Given a fully selfextensional logic S, we find sufficient conditions under which the Vietoris endofunctor V on S-referential algebras can be defined and we propose to define the modal expansions of S as the logic that arises from the V-coalgebras. As an example, we also show how the Vietoris endofunctor on referential algebras extends the Vietoris endofunctor on Stone spaces. From another point of view, we examine when a category of ‘spaces’ (X,A), ie sets X …

Pattern-Based Model Transformation: A Metamodel-Based Approach To Model Evolution, Sheena Judson Miller

LSU Doctoral Dissertations

Software systems continue to grow in complexity at a rapid pace, creating systems that are complex to build and evolve. The problems that accompany changes in requirements, system upgrades, and error correction produce a desire for software evolution methods that increase the efficiency and effectiveness of adapting complex software to changes. As software systems evolve, design models must be modified to accommodate the required changes. Techniques that control the changes to models in a systematic manner are a key to model evolution. A process that improves the ability to effectively modify a design, thereby enhancing design qualities, supports the need …

Stormwater Diversion As A Potential Coastal Wetland Restoration Method, Jennifer Howard Woods

LSU Master's Theses

The Barataria-Terrebonne estuary has been eroding at a rate of up to 103.6 km2 yr-1 for several decades. If the current rate of loss is not reduced, an additional 2,550 km2 of coastal wetlands will be lost by the year 2050. Currently, stormwater in Terrebonne Parish is pumped into canals, ultimately discharging into the Gulf of Mexico. An opportunity exists to use this stormwater for wetland restoration; however, the ecological impacts of stormwater diversions on wetlands are unknown. The objectives of this project were to 1) to investigate the seed banks of a degraded marsh to determine if a viable …

Comparing Models For Measuring Ring Strain Of Common Cycloalkanes, Brad A. Hobbs

The Corinthian

The number of carbon atoms bonded in the ring of a cycloalkane has a large effect on its energy. A molecule's energy has a vast impact on its stability. Determining the most stable form of a molecule is a useful technique in the world of chemistry. One of the major factors that influence the energy (stability) of cycloalkanes is the molecule's ring strain. Ring strain is normally viewed as being directly proportional to the instability of a molecule. It is defined as a type of potential energy within the cyclic molecule, and is determined by the level of "strain" between …

Extending Uml-Rt For Control System Modelling, Qimin Gao, Lyndon Brown, Luiz Fernando Capretz

Electrical and Computer Engineering Publications

There is a growing interest in adopting object technologies for the development of real-time control systems. Several commercial tools, currently available, provide object-oriented modeling and design support for real-time control systems. While these products provide many useful facilities, such as visualization tools and automatic code generation, they are all weak in addressing the central characteristic of real-time control systems design, i.e., providing support for a designer to reason about timeliness properties. We believe an approach that integrates the advancements in both object modeling and design methods and real-time scheduling theory is the key to successful use of object technology for …

Iowa Academy Of Science 116th Annual Meeting [2004]: Advance Program, Iowa Academy Of Science

Iowa Academy of Science Documents

No abstract provided.

Risk Management Criteria For Metals At Blm Mining Sites, Karl L. Ford

United States Bureau of Land Management: Staff Publications

This report sets forth acceptable soil and sediment criteria for heavy metals released from abandoned hard rock mining sites as they relate to ecosystem management and protection of human health and wildlife. The USDI Bureau of Land Management (BLM) manages approximately 270 million acres of public lands, primarily in the Western U.S. These lands include several hundred thousand abandoned mining sites, some of which may be releasing heavy metals into the environment at levels toxic to wildlife.

Algebraic Semantics For Coalgebraic Logics, Clemens Kupke, Alexander Kurz, Dirk Pattinson

Engineering Faculty Articles and Research

With coalgebras usually being defined in terms of an endofunctor T on sets, this paper shows that modal logics for T-coalgebras can be naturally described as functors L on boolean algebras. Building on this idea, we study soundness, completeness and expressiveness of coalgebraic logics from the perspective of duality theory. That is, given a logic L for coalgebras of an endofunctor T, we construct an endofunctor L such that L-algebras provide a sound and complete (algebraic) semantics of the logic. We show that if L is dual to T, then soundness and completeness of the algebraic semantics immediately yield the …

A 2-Chain Can Interlock With A K-Chain, Julie Glass, Stefan Langerman, Joseph O'Rourke, Jack Snoeyink, Jianyuan K. Zhong

Computer Science: Faculty Publications

One of the open problems posed in [3] is: what is the minimal number k such that an open, flexible k-chain can interlock with a flexible 2-chain? In this paper, we establish the assumption behind this problem, that there is indeed some k that achieves interlocking. We prove that a flexible 2-chain can interlock with a flexible, open 16-chain.

Better Foreground Segmentation Through Graph Cuts, Nicholas Howe, Alexandra Deschamps

Computer Science: Faculty Publications

For many tracking and surveillance applications, background subtraction provides an effective means of segmenting objects moving in front of a static background. Researchers have traditionally used combinations of morphological operations to remove the noise inherent in the background-subtracted result. Such techniques can effectively isolate foreground objects, but tend to lose fidelity around the borders of the segmentation, especially for noisy input. This paper explores the use of a minimum graph cut algorithm to segment the foreground, resulting in qualitatively and quantitiatively cleaner segmentations. Experiments on both artificial and real data show that the graphbased method reduces the error around segmented …

Computational Geometry Column 45, Joseph O'Rourke

Computer Science: Faculty Publications

The algorithm of Edelsbrunner for surface reconstruction by "wrapping" a set of points in R³ is described.

2004 File Geodatabase Containing Photo Point Locations, Aerial Photos, And Flight Maps, City Of Tampa Department Of Sanitary Sewers Bay Study Group, Pete Reehling, Richard Mckenzie

Data Sets

The Bay Study Group was created by the City of Tampa in 1976 to monitor the effects of pollution abatement that occurred in Hillsborough Bay when the city’s wastewater treatment plant was upgraded from primary to advanced treatment in 1979. The Bay Study Group documented a remarkable restoration of water quality parameters and biological indicators in Hillsborough Bay from the mid 1980s until 2009, when it was disbanded. This zip Geodatabase file contains the photo point locations, aerial photos, and flight maps for the year 2004.

2004 File Geodatabase Containing Aerial Photos, Pete Reehling, Richard Mckenzie, City Of Tampa Department Of Sanitary Sewers Bay Study Group

Images

The Bay Study Group was created by the City of Tampa in 1976 to monitor the effects of pollution abatement that occurred in Hillsborough Bay when the city’s wastewater treatment plant was upgraded from primary to advanced treatment in 1979. The Bay Study Group documented a remarkable restoration of water quality parameters and biological indicators in Hillsborough Bay from the mid 1980s until 2009, when it was disbanded. This zip Geodatabase file contains the aerial photos for the year 2004.

Simulated Changes In Shallow Groundwater And Vegetation Distributions Under Different Reservoir Operations Scenarios, Mark Cable Rains, Jeffery F. Mount, Eric W. Larsen

Geology Faculty Publications

The objectives of this study were to develop and use a linked groundwater and vegetation model to simulate groundwater and vegetation distributions in a riverine and reservoir-fringe system under different reservoir operations scenarios. This study was conducted where Little Stony Creek flows into East Park Reservoir on the east front of the Coast Range, northern California. A numerical groundwater model was used to model mean depth to groundwater during the growing season for water years 1980–1999 for each of five community types identified on the study site. Multiple vegetation models were developed, each of which described the probability that a …

Interactive Regulation Of Dissolved Copper Toxicity By An Estuarine Microbial Community, Christina L. Dryden, Andrew S. Gordon, John R. Donat

OES Faculty Publications

Cultured marine microorganisms under copper stress produce extracellular compounds having a high affinity for copper (copper-complexing ligands). These ligands are similar in binding strength to those found in natural waters, but few studies have examined the relationship between copper, copper-complexing ligand concentrations, and natural microbial populations. A series of in situ experiments in the Elizabeth River, Virginia, revealed that an intact estuarine microbial community responded to copper stress by production of extracellular, high-affinity copper-complexing ligands. The rate of ligand production was dependent on copper concentration and resulted in a reduction of the concentration of free cupric ions, Cu²⁺, …

Modeled And Observed Empirical Orthogonal Functions Of Currents In The Yucatan Channel, Gulf Of Mexico, Lie-Yauw Oey, Tal Ezer, Wilton Sturges

CCPO Publications

Candela et al. [2003] have reported empirical orthogonal function (EOF) analyses based on 23-month current-meter and acoustic Doppler current profiler measurements in the Yucatan Channel. Those authors noted the difference between EOFs obtained from observations and their z-level models and EOFs calculated by Ezer et al. [2003] from the results of a terrain-following model. Here a new analysis is reported that explains this difference, and that also suggests the importance of shelf-edge meander mode of the core Loop Current in the channel. We show that the terrain-following model gives EOFs with characteristics similar to those observed when data from the …

Foreland Basins: Lithospheric Flexure, Plate Strength And Regional Stratigraphy, John Londono

LSU Doctoral Dissertations

Foreland basin subsidence through time is reproduced in this study, as the flexure of an elastic beam in an inviscid fluid under the vertical stress, caused by discrete-distributed loads. Thus, seismostratigraphic data from the Timor Sea peripheral foreland basin, in northwestern Australia, and the Putumayo retroarc foreland basin in the Colombian Andes, are forward modeled, at chronostratigraphic intervals, to assess the evolving geodynamic conditions of the basins. Results show that the accommodation in foreland basins varies as the depositional basement is vertically adjusted according to the regionally isostatic compensation of the lithosphere. Distributed tectonic (thrust belts) and sedimentary loads that …