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Articles 2191 - 2220 of 2315

Full-Text Articles in Physical Sciences and Mathematics

Structural And Electronic Properties Of Aluminum Nano Clusters By Dft, Mrudula Raparla Jan 2010

Structural And Electronic Properties Of Aluminum Nano Clusters By Dft, Mrudula Raparla

Open Access Theses & Dissertations

The electronic properties of Al clusters containing up to 60 atoms are investigated using an all electron density functional theory using large polarized Gaussian basis sets with 39 Gaussians per atom (NRLMOL basis). We have performed an extensive search for the lowest energy isomers for clusters up to Al 21. We build a database of candidate structures for the ground state using different strategies. First, a few structures are randomly generated and fully relaxed using plane wave pseudo potential method. We also performed simulated annealing runs using ab initio molecular dynamics for clusters up to Al20. In three sets of …


Spectroscopic Study Of The Inhibition Of Calcium Oxalate Calculi By Larrea Tridentata, Luis Alonso Pinales Jan 2010

Spectroscopic Study Of The Inhibition Of Calcium Oxalate Calculi By Larrea Tridentata, Luis Alonso Pinales

Open Access Theses & Dissertations

The causes of urolithiasis include such influences as diet, metabolic disorders, and genetic factors which have been documented as sources that aggravate urinary calculi depositions and aggregations, and, implicitly, as causes of urolithiasis. This study endeavors to detail the scientific mechanisms involved in calcium oxalate calculi formation, and, more importantly, their inhibition under growth conditions imposed by the traditional medicinal approach using the herbal extract, Larrea tridentata. The calculi were synthesized without and with Larrea tridentata infusion by employing the single diffusion gel technique. A visible decrease in calcium oxalate crystal growth with increasing amounts of Larrea tridentata herbal infusion …


Conversion Of Racemic Ibuprofen To (S)-Ibuprofen, David Chavez-Flores Jan 2010

Conversion Of Racemic Ibuprofen To (S)-Ibuprofen, David Chavez-Flores

Open Access Theses & Dissertations

Ibuprofen is a common Non-Steroidal Anti-Inflammatory Drug (NSAID) sold as a racemic or equal mixture of (R) and (S) mirror-image enantiomers. Without patent protection, ibuprofen is an orphan drug even though one enantiomer, (S)-ibuprofen, provides relief three times faster than its racemic mixture with fewer side effects. The goal of this research was to develop a facile, environmentally benign (no waste of ibuprofen or catalysts), and inexpensive process to convert a commercially available racemic mixture of ibuprofen to the therapeutically active (S)-ibuprofen.

After many attempts, the most successful conversion of racemic ibuprofen to (S)-ibuprofen was the in situ racemization and …


Characterization Of Mantle/Crust Interactions Using Pb Isotope Analyses Of Lavas In The Southern Rio Grande Rift, New Mexico, Lynnette Crocker Jan 2010

Characterization Of Mantle/Crust Interactions Using Pb Isotope Analyses Of Lavas In The Southern Rio Grande Rift, New Mexico, Lynnette Crocker

Open Access Theses & Dissertations

The Pb isotope composition of volcanic rocks in the Rio Grande Rift (RGR) can be used to investigate the interaction of mantle melts with continental lithosphere, and has important implications for the composition of the lithosphere. We suggest some compositional signatures may pre-date current tectonic processes. Existing data from several volcanic fields in New Mexico show a converging pattern on a very limited Pb isotope range, corresponding to lower crustal xenolith compositions from Kilbourne Hole. The different volcanic fields show Pb isotope trends diverging from this lower crustal composition, likely depicting mixing with different upper crustal reservoirs. These very common, …


Gaze, Turn-Taking And Proxemics In Multiparty Versus Dyadic Conversation Across Cultures, David Alberto Herrera Jan 2010

Gaze, Turn-Taking And Proxemics In Multiparty Versus Dyadic Conversation Across Cultures, David Alberto Herrera

Open Access Theses & Dissertations

When people converse with others, they participate in joint interaction behaviors, like proxemics or interpersonal distance, mutual gaze, and turn-taking or pause and overlap, which they may not consciously negotiate. How these behaviors manifest depends on many factors, such as gender, age, personality, culture, and number of participating conversants. Understanding these differences is important for situations where intercultural joint interaction behaviors are necessary for mission success, such as for military personnel in foreign countries. They may also be useful for modeling embodied conversational agents where culture and group vary. Joint interaction behaviors have been extensively studied for American dyads, and …


Synthesis And Manufacture Of Photocrosslinkable Poly(Caprolactone)-Based 3d Scaffolds For Tissue Engineering Applications, Nathan Jonathan Castro Jan 2010

Synthesis And Manufacture Of Photocrosslinkable Poly(Caprolactone)-Based 3d Scaffolds For Tissue Engineering Applications, Nathan Jonathan Castro

Open Access Theses & Dissertations

It is known that the body can efficiently repair hard tissue (bone) micro fractures by suturing the defect through the deposition of minerals resulting in an area that is stronger post-injury. Larger defects, however, generally cause more trouble since the body is incapable of repairing them. Bone defects can occur as a result of congenital abnormalities, trauma, or disease. Traditional methods for addressing these defects have involved the use of acellular cadaverous bone or autologous bone. Both contain innate problems associated with them; the former method can result in disease transmission, as well as very low integration with the host …


Copper Isotope Fractionation During Surface Adsorption And Intracellular Incorporation By Bacteria, Jesica Urbina Navarrete Jan 2010

Copper Isotope Fractionation During Surface Adsorption And Intracellular Incorporation By Bacteria, Jesica Urbina Navarrete

Open Access Theses & Dissertations

Copper isotopes may prove to be a useful tool for investigating bacteria-metal interactions recorded in natural waters, soils, and rocks. However, experimental data that constrain Cu isotope fractionation in biologic systems are limited and unclear. In this study we utilized Cu isotopes (65Cu) as a tool to investigate Cu-bacteria interactions, including surface adsorption and intracellular incorporation. Experiments were conducted with individual Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacterial species as well as with bacterial consortia from several natural environments. Adsorption experiments were conducted with live or dead cells over the pH range 2.5 to 6. Surface adsorption of Cu …


Scrap Reduction Model: By Combination Of Dmaic And Design Of Experiments, Anoop J. Randive Jan 2010

Scrap Reduction Model: By Combination Of Dmaic And Design Of Experiments, Anoop J. Randive

Open Access Theses & Dissertations

This project deals with the experimentation which took place at a cable manufacturing company. The thesis describes and summarizes the various strategies and techniques that has been applied and practiced for scrap reduction. DMAIC and Six Sigma Technology has been proven very help full in order to reduce scrap to a major extent. DMAIC help to identify areas in process where extra expense exist, identify the biggest impact factor related production expenses, introduce appropriate measurement system, optimize process and reduce production cost and time. Many issues were detected by the production, such as a lack of a unified procedure for …


Enthalpies Of Mixing Of Water And Alkoxyethanols, John Enriquez Jan 2010

Enthalpies Of Mixing Of Water And Alkoxyethanols, John Enriquez

Open Access Theses & Dissertations

Alkoxyethanols [CmH2m+1·(OC2H4)·OH] (conveniently abbreviated to CmE1) are a subgroup of the alkyl poly(ethylene glycol) mono-ethers. They are small relatives of a large number of non-ionic detergents. The thermodynamic properties of their mixing in water have been shown to be good sources of information about the interactions of both hydrophilic and hydrophobic groups with water. Theses alkoxyethanols, or glycol ethers, are the ether derivatives of ethylene glycol where one hydroxyl functional group is substituted for an alkoxy functional group. Our group has already published results for aqueous excess properties …


Function Point Analysis In Computer Science Capstone Projects, Evelyn Torres Jan 2010

Function Point Analysis In Computer Science Capstone Projects, Evelyn Torres

Open Access Theses & Dissertations

Capstone projects at the Computer Science Department at the University of Texas at El Paso allow students to demonstrate their knowledge of software engineering. During the capstone project, students work on a project that simulates industry; students have a client and a supervising team. Before a project is implemented, professors must assess the project to ensure consistency with previous projects and a significant experience for the students. Currently, a project is assessed primarily on past experiences. In industry, agreeing to completing and delivering a project without assessing the scope and estimating the project cost is neither acceptable nor profitable. Similarly …


Bayesian Nonparametric Regression With A Flexible Error Term Distribution, Courtney Marie Barnes Jan 2010

Bayesian Nonparametric Regression With A Flexible Error Term Distribution, Courtney Marie Barnes

Open Access Theses & Dissertations

Datasets often exhibit heavy tailed behavior and standard analyses are often heavily influenced by outliers. We propose a nonparametric regression model whose error term distribution is a mixture of a normal and a Student t distribution. This results in a model that is more resistant to outliers compared to a model with a normal error term.


Transfer Learning Techniques For Deep Neural Nets, Steven M. Gutstein Jan 2010

Transfer Learning Techniques For Deep Neural Nets, Steven M. Gutstein

Open Access Theses & Dissertations

Inductive learners seek meaningful features within raw input. Their purpose is to accurately categorize, explain or extrapolate from this input. Relevant features for one task are frequently relevant for related tasks. Reuse of previously learned data features to help master new tasks is known as &lsquo transfer learning &rsquo. People use this technique to learn more quickly and easily. However, machine learning tends to occur from scratch.

In this thesis, two machine learning techniques are developed, that use transfer learning to achieve significant accuracy for recognition tasks with extremely small training sets and, occasionally, no task specific training. These methods …


Physical And Biochemical Assessment Of Mexican Palo Verde Response To Chromium Toxicity, Yong Zhao Jan 2010

Physical And Biochemical Assessment Of Mexican Palo Verde Response To Chromium Toxicity, Yong Zhao

Open Access Theses & Dissertations

In the United States, about 1/3 of the 1400 superfund sites have been reported to be chromium contaminated, making chromium the second most common metal found in superfund chemical contamination sites. Chromium removal from soil has commonly been carried out via chemical, physical, and thermal processes. However, these methods are expensive and/or invasive to local ecosystems. In contrast to these techniques, phytoremediation (the use of plants to remove toxic substances from areas containing contamination at low or medium levels) appears to be a cost-effective and environmentally friendly process for chromium removal. However, most reports on chromium phytoremediation suggest that this …


Investigations Of Grade Control, Macarthur Mine, Yerington, Nevada: An Oxidized Porphyry Copper System, Joseph Daniel Louis Lori Jan 2010

Investigations Of Grade Control, Macarthur Mine, Yerington, Nevada: An Oxidized Porphyry Copper System, Joseph Daniel Louis Lori

Open Access Theses & Dissertations

Supergene enriched, low-grade oxidized porphyry copper deposits are of great economic value. Oxidized porphyry sections are economic targets because even low-grade prospects have the potential to produce low-cost copper in an environmentally friendly fashion due to easy leachability and high recovery rates of the oxide mineralization. The MacArthur Mine, in the historic Yerington mining district of Nevada, is the focus of this study. The MacArthur is a tilted oxidized porphyry deposit, partially mined by open pit methods, hosted in the Jurassic Bear Quartz Monzonite of the Yerington batholith. The objective of the study is to define controls of copper oxide …


Ontology-Driven Discovery Of Scientific Computational Entities, Pearl W. Brazier Jan 2010

Ontology-Driven Discovery Of Scientific Computational Entities, Pearl W. Brazier

Open Access Theses & Dissertations

Many geoscientists use modern computational resources, such as software applications, Web services, scientific workflows and datasets that are readily available on the Internet, to support their research and many common tasks. These resources are often shared via human contact and sometimes stored in data portals; however, they are not necessarily available for metadata annotations that can assist in collaborative research or machine processing. Scientists' knowledge of their resources and processes are at risk of being lost. A scientist-driven discovery environment, which assumes a level of technical expertise generally possessed by a geoscientist, is needed to enable discovery and comparisons of …


Bagc.M: Three Dimensional Gravity Modeling Software With An Application In Death Valley, Ca, Brian Eugene Eslick Jan 2010

Bagc.M: Three Dimensional Gravity Modeling Software With An Application In Death Valley, Ca, Brian Eugene Eslick

Open Access Theses & Dissertations

Basin Anomaly Gravity Calculator (BAGC.m) is a 3D interactive gravity modeling package designed to create, edit, and calculate the gravitational attraction of basin models entirely within the MATLABTM environment. Gravity anomalies are calculated using the Rectangular Prism Method (Bott, 1960; Kane, 1962; and Plouff, 1966) which subdivides earth models into regularly spaced rectangular prisms. This approach requires large 3D matrices to store most realistic earth models. The process of model editing is simplified by storing basins as 2D gridded files which define the depth to the boundary between basement rock and sedimentary fill for each model cell. In order to …


Titanium Niobium Nano Porous Materials: New Photocatalysts For Water Decontamination, Maryam Zarei Chaleshtori Jan 2010

Titanium Niobium Nano Porous Materials: New Photocatalysts For Water Decontamination, Maryam Zarei Chaleshtori

Open Access Theses & Dissertations

Water pollution is major environmental problem worldwide. Many common industrial organic compounds that make their way into water systems can be carcinogenic at trace levels and are difficult and costly to remove completely with conventional technologies. Because of this, authorities and researchers are trying to improve current water cleanup techniques.

Heterogeneous photocatalysts that accelerate the photocatalytic destruction of organic contaminants in water are a potentially inexpensive and highly effective way to remove both trace-level and saturated harmful compounds from industrial waste streams and drinking water. Titanium dioxide has the potential to completely mineralize organic compounds in water under ultraviolet light. …


Hydrological Characteristics Of A Large-Scale Flooding And Draining Experiment, Barrow, Alaska, Edith Jaurrieta De Velasco Jan 2010

Hydrological Characteristics Of A Large-Scale Flooding And Draining Experiment, Barrow, Alaska, Edith Jaurrieta De Velasco

Open Access Theses & Dissertations

The Arctic appears to be affected by climate change more so than any other region on Earth. Some of the most significant climate change impacts reported for the Arctic are associated with dramatic shifts in the hydrologic regime of terrestrial ecosystems. Understanding the hydrologic processes that are associated with different components of arctic terrestrial ecosystems is important because water in the form of snow or rain influences a range of properties and processes such as land-atmosphere energy and trace gas fluxes, nutrient cycling, ecosystem dynamics, biodiversity, periglacial processes and surface albedo. Furthermore, plants, animals, and native people of the Arctic …


Renewable Energy Integration: An Approach For Micro-Grid Optimization., Nicolas Lopez Jan 2010

Renewable Energy Integration: An Approach For Micro-Grid Optimization., Nicolas Lopez

Open Access Theses & Dissertations

This thesis explores the Renewable Energy Integration Problem beginning with a literature review on the different sources of electrical energy classified as Non-Renewable and Renewable, stating that the integration of renewable sources within the pre-existing Power-Grids is a current worldwide problem that is being addressed with different approaches.

The impossibility to exactly model the different equations relating the electric output of the renewable energy sources as they relate with meteorological factors, makes the renewable sector a stochastic component of the overall mathematical model, where it can be concluded that most of the problem is in the area of the forecast. …


A Gis-Based Emission And Air Quality Impact Assessment For Evaluating Transportation Mitigation Measures, Jose Maria Mares Jan 2010

A Gis-Based Emission And Air Quality Impact Assessment For Evaluating Transportation Mitigation Measures, Jose Maria Mares

Open Access Theses & Dissertations

The research presented here develops a framework that assesses a transportation project's air quality impact. The framework not only integrates transportation and emission modeling but also improves the accuracy of the emission estimates. In order to do this, the framework makes use of six modules: environmental conditions data input, GIS database, emission modeling, transportation network, post-processing, and graphical presentation. Each module aims to improve the quality and accuracy of the inputs used by MOBILE6.2. In addition, the framework has the capability, among other features, of presenting the emission estimates in a GIS-based modeling platform that enables the analyst to spatially …


Granulometry And Geochemistry Of Dust Emission From Owens (Dry) Lake, California, Analila Rojo Jan 2010

Granulometry And Geochemistry Of Dust Emission From Owens (Dry) Lake, California, Analila Rojo

Open Access Theses & Dissertations

Owens (dry) Lake, the terminus of Owens River, is located in the Basin and Range physiographic province in east–central California. The transformation of Owens Lake into a desiccated desert playa (approximately 280 km2) via diversion of the river into the Los Angeles Aqueduct (in 1913) led to extensive wind erosion, making the playa one of the most intense sources of airborne dust in the Western Hemisphere. The processes that direct the chemical and mineralogical composition of surface sediments at Owens (dry) Lake and the physical mechanisms of wind erosion, saltation and dust emission at Owens (dry) Lake are well–understood. However, …


Mineralization In The San Juan Mountains, Colorado, William M. Sheriff Jan 2010

Mineralization In The San Juan Mountains, Colorado, William M. Sheriff

Open Access Theses & Dissertations

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Seismic Investigation Of The Southern Rio Grande Rift, Lennox Emmanuel Thompson Jan 2010

Seismic Investigation Of The Southern Rio Grande Rift, Lennox Emmanuel Thompson

Open Access Theses & Dissertations

Competing models exist to explain what caused the Earth's crust to spread apart 29 million years ago to create a region known today as the Rio Grande Rift (RGR). The RGR extends from central Colorado through New Mexico to northern Mexico, near El Paso. The RGR has different geologic features that distinguish it from most other valleys (e.g., the RGR was not cut by a river nor does a river branch upstream). A growing body of evidence shows that geologic activity still occurs in the RGR, with a continuation of faulting, seismicity and widening at a small rate of about …


The Use Of Social Marketing As A Means Of Promoting Enviornmental Conservation: A Case Study Of Indonesian Biodiversity Campaigns, Alesia Za Gara Jan 2010

The Use Of Social Marketing As A Means Of Promoting Enviornmental Conservation: A Case Study Of Indonesian Biodiversity Campaigns, Alesia Za Gara

Open Access Theses & Dissertations

As a means of preserving Indonesia's natural allure and resources it is evident that there must be a conscious shift made wherein environmental conservation becomes top priority among the people of Indonesia and the world. Traditionally dealt with through a country's governmental facets, a new tread of social marketing is now being employed ENGOs in various countries such as Indonesia as a way to promote biodiversity conservation. For example, one such ENGO is Rare Conservation, an international organization that teaches social marketing tools to classes or cohorts of individuals around the world as a means of improving a variety of …


Observer-Dependent Model For Analyzing Subjective Parameters In Epidemiology, Milad Zarei Jan 2010

Observer-Dependent Model For Analyzing Subjective Parameters In Epidemiology, Milad Zarei

Open Access Theses & Dissertations

Although medical technologies for preventing the contagion and spread of infectious diseases have improved steadily throughout the last century, new infectious diseases are still emerging and spreading swiftly. The modeling of infectious disease spread is crucial in addressing the lack of predictive ability in epidemiology. Managing the spread of infectious diseases requires processing quantitative epidemiological data and the ability to capture the dynamics of the infectious disease in order to provide a measure of control.

In this thesis, I have introducing cognitive biases in diseases spread modeling. For the first time, to the author's knowledge, the human subjective experience has …


On Relational Quantum Mechanics, Oscar Acosta Jan 2010

On Relational Quantum Mechanics, Oscar Acosta

Open Access Theses & Dissertations

A problem facing quantum mechanics is that there are a number of views or interpretations available that purport to 'explain' quantum mechanics. In this paper I discuss and analyze the view of relational quantum mechanics by Carlo Rovelli in the context of theoretical underdetermination. I will show that even though Rovelli offers a view that consolidates some of the aspects of competing theories it still falls short of breaking out of the theoretical underdetermination. The criteria that I have used to consider a theory successful in this context is one that increases the predictive output of quantum theory. Lacking an …


An Ab-Initio Study Of The Elastic Properties Of Important Group Iv Diborides At High Temperatures, Manny Gonzales Jan 2010

An Ab-Initio Study Of The Elastic Properties Of Important Group Iv Diborides At High Temperatures, Manny Gonzales

Open Access Theses & Dissertations

Presented is an ab-initio Molecular Dynamics (MD) study, employing the Density Functional Theory (DFT), of the lattice parameter, thermal expansion coefficients and elastic constants of ZrB2, TiB2 and HfB2 as a function of temperature. The MD trajectories provide the equilibrium lattice parameters at finite temperatures, and the gradient of the energy from these equilibrium solutions is then used to calculate the components of the stiffness tensor. The results for ZrB2 are shown to agree well with reported experimental results for the lattice parameters and elastic constants as a function of temperature.


Controlling Features And Processes For Radionuclide Release From Unsaturated Zone Geological Repositories, Lubna K. Hamdan Jan 2010

Controlling Features And Processes For Radionuclide Release From Unsaturated Zone Geological Repositories, Lubna K. Hamdan

Open Access Theses & Dissertations

In the long run, nuclear waste packages will fail gradually due to localized and general corrosion and radionuclides will be transported to the accessible environment by ground water.

Two main failure scenarios are expected for the waste packages: Flow-through model and bathtub model; in the flow-through model water flows through the waste container, while in the bathtub model water pools inside the waste package. The Department of Energy, in their performance assessment of the proposed repository at Yucca Mountain, excluded the bathtub model from their analysis and assumed the diffusion and advection to be in the same direction in the …


A New Green Chemistry Method Based On Plant Extracts To Synthesize Gold Nanoparticles, Milka Odemariz Montes Castillo Jan 2010

A New Green Chemistry Method Based On Plant Extracts To Synthesize Gold Nanoparticles, Milka Odemariz Montes Castillo

Open Access Theses & Dissertations

Extraordinary chemical and physical properties exhibited by nanomaterials, as compared to their bulk counterparts, have made the area of nanotechnology a growing realm in the past three decades. It is the nanoscale size (from 1 to 100 nm) and the morphologies of nanomaterials that provide several properties and applications not possible for the same material in the bulk. Magnetic and optical properties, as well as surface reactivity are highly dependent on the size and morphology of the nanomaterial. Diverse nanomaterials are being widely used in molecular diagnostics as well as in medicine, electronic and optical devices. Among the most studied …


Information Sharing Across Private Databases, Swapnil Suresh Samant Jan 2010

Information Sharing Across Private Databases, Swapnil Suresh Samant

Open Access Theses & Dissertations

While the explosion of availability of information has become invaluable in modern society, it has also raised valid concerns about erosion of privacy. More and more, different entities are encouraged to share information in order to discover potential security risks, health pattern, or social behavior trends. However, some of this information is sensitive. Owners of information may be unwilling to share their whole databases with other entities, either to protect the privacy of the records, or because of the proprietary nature of the information.

We consider the following problem. How can we compute the intersection and the equijoin of databases …