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Articles 2371 - 2400 of 2636

Full-Text Articles in Physical Sciences and Mathematics

Preliminary Assessment Of Pharmaceuticals And Personal Care Products (Ppcps) In Natural Waters In The El Paso Del Norte Area And Their Impacts On Aquatic Invertebrates, Sarah T. Baca^, Wen-Yee Lee, Jennifer Martinez, Rodolfo Guerrero, Elizabeth J. Walsh* Mar 2011

Preliminary Assessment Of Pharmaceuticals And Personal Care Products (Ppcps) In Natural Waters In The El Paso Del Norte Area And Their Impacts On Aquatic Invertebrates, Sarah T. Baca^, Wen-Yee Lee, Jennifer Martinez, Rodolfo Guerrero, Elizabeth J. Walsh*

COURI Symposium Abstracts, Spring 2011

The Rio Grande is a major source of water for humans and wildlife. The types and concentrations
of PPCPs, and their impacts on aquatic life, in the river are virtually unknown. The purpose of this
research is to assess their impact on aquatic invertebrates and establish the concentrations of these contaminants in the river and an adjacent wetland. Water and sediment samples were collected from the river and the wetland. Water chemistry parameters were monitored and samples were retained for PPCP analyses. Invertebrates were exposed to PPCPs using modified life cycle tests. LC50 values for caffeine for chironomids ranged from …


Mapping Unmarked Graves In The Mescalero Apache Indian Reservation, Ashley Galusina Nauer^, Stephanie Chavez^, Laura Serpa* Mar 2011

Mapping Unmarked Graves In The Mescalero Apache Indian Reservation, Ashley Galusina Nauer^, Stephanie Chavez^, Laura Serpa*

COURI Symposium Abstracts, Spring 2011

Citizens living on the Apache Indian Reservation in Mescalero, New Mexico have experienced difficulty in burying their dead because when they dig a new grave, they often find a body from an earlier burial. The reservation does not have rigorous rules on locating and marking graves and, thus, there are numerous unmarked burial sites within and outside of the existing cemeteries. Officials from the reservation approached the Geological Sciences Department for assistance to map grave locations in the area’s three graveyards. In this project, we will use shallow ground-penetrating radar (GPR) to find the graves and digital global positioning system …


Novel Approach To New Endohedral Fullerenes, Elias J. Munoz Iii^, Luis Echegoyen* Mar 2011

Novel Approach To New Endohedral Fullerenes, Elias J. Munoz Iii^, Luis Echegoyen*

COURI Symposium Abstracts, Spring 2011

Since the discovery of C60 many different allotropes of carbon have been found, isolated and researched. Of particular interest, Ugarte et al in 1992 first reported the observation of onion-like structures known as carbon nano onions (CNOs). They consist of concentric fullerene cages separated by the same distance as the layers of graphite. These carbon nanoparticles can be obtained from either arc discharge of graphite under water or by thermal annealing of nanodiamonds. Through the annealing process using the nanodiamonds, 6 to 8 layer onions can be obtained on average.

It has been demonstrated that multi-walled nanotubes (MWNT) can be …


Synthesis Of Pyridine-Based Ligands As Potential Magnetic Liquid Crystals, Jacqueline Gamboa Varela^, Jose E. Nunez* Mar 2011

Synthesis Of Pyridine-Based Ligands As Potential Magnetic Liquid Crystals, Jacqueline Gamboa Varela^, Jose E. Nunez*

COURI Symposium Abstracts, Spring 2011

Ligands for the development of metallomesogens (metal-containing-liquid-crystals) have attracted attention due to potential applications in materials science such as optical devices, magnetic switches, and conductors. The attempts to synthesize bis(3-alkoxy) pyridine amines are presented. These structures are designed to exhibit liquid crystalline properties as metal complexes. Reaction conditions using potassium carbonate and potassium tert-butoxide as bases under Ullmann-type conditions in various solvents (aromatic and non-aromatic), between -78 ⁰C to 160 ⁰C, have been unsuccessful. It is imperative to understand the electronic effects of the meta-substituted pyridine precursors to further develop the copper-catalyzed conditions of these types of molecules.


Studies Of Seismicity Near The Active Volcano Mt. Spurr, Sarah J. Olivas^, Diane I. Doser* Mar 2011

Studies Of Seismicity Near The Active Volcano Mt. Spurr, Sarah J. Olivas^, Diane I. Doser*

COURI Symposium Abstracts, Spring 2011

Seismicity patterns and fault orientations can indicate local stress fields related to volcanic eruptions. There have been many moderate magnitude, shallow earthquakes occurring in the Strandline Lake region about 100km from Anchorage, Alaska near the active volcano, Mt. Spurr. Previous researchers have found that the local stress under Mt. Spurr, before and after its 1992 eruption (1992-1997), differed from the regional stresses, which are related to subduction of the Pacific Plate and Yakutat micro plate. We are analyzing location and patterns of earthquakes occurring since 1998 to determine if more recent seismicity is similar to that occurring before or after …


Bis( N, N-Dipheny-3-Pyridineamine) Tungsten Complex As Molecular Gyroscope, Verenice Ramirez^, Jose E. Nunez* Mar 2011

Bis( N, N-Dipheny-3-Pyridineamine) Tungsten Complex As Molecular Gyroscope, Verenice Ramirez^, Jose E. Nunez*

COURI Symposium Abstracts, Spring 2011

In recent years, the interest in molecular machines has increased based on inspiration from macroscopic machines, such as gyroscopes applied in racecar engines and arrays of gyroscopes in automatic pilot functions. The same concept has been taken down to the nanoscopic level as molecular machines in solution like bevel gears and turnstiles, but for application use they must be in the solid state. Gyroscope molecules can exhibit fast rotation and the aim is to design free rotation in the crystal lattice that maintains volume conserving motion. Bis(N,N-diphenyl-3-pyridinamine) tungsten complex was prepared by irradiation of tungsten hexacarbonyl in the presence of …


Equations Of State Of A Strongly Interacting Dense Fermion System, Jason P. Keith^, Efrain J. Ferrer* Mar 2011

Equations Of State Of A Strongly Interacting Dense Fermion System, Jason P. Keith^, Efrain J. Ferrer*

COURI Symposium Abstracts, Spring 2011

Our ultimate goal is to study the possibility of color superconductivity in neutron stars. Under the high densities that prevail within some neutron stars the quarks are liberated from the nucleons, and due to their strong interaction they can form di-quark pairs that act as Cooper pairs in a BCS phase. If the interaction between the quarks is stronger than it is for the Cooper pairs, which could be realized if the stars density is decreased, then the pairs can become Bose-Einstein condensates, with totally different characteristics. We investigate the equations of state in the two mentioned regimes of dense …


Using Gravitational And Magnetic Data To Understand Interactions Between Active Seismic Zones Within The Interior Of Alaska, Shane M. Schinagel^, Diane I. Doser* Mar 2011

Using Gravitational And Magnetic Data To Understand Interactions Between Active Seismic Zones Within The Interior Of Alaska, Shane M. Schinagel^, Diane I. Doser*

COURI Symposium Abstracts, Spring 2011

Differences in rock density, along with changes in the orientation of the magnetic field, provide vital information about the tectonic environment within the interior of Alaska in a region where outcrop exposure is poor due to recent glacial and fluvial activity.  Analysis of the gravity and magnetic field can help identify relationships between recent (1989-2008) and historic (pre-1971) seismicity and suspected strike-slip, reverse, and thrust faults within the region, as differences in density and magnetic properties of materials may be observed across fault zones.  Our overall objective is to better understand the complicated interactions between the strike-slip Denali fault system …


Effects Of Cerium Oxide Nanoparticles On Glycine Max Grown In Hydroponics, Alyssa De La Rosa^, Jose Peralta, Jeff Terry, Jorge Gardea-Torresdey* Mar 2011

Effects Of Cerium Oxide Nanoparticles On Glycine Max Grown In Hydroponics, Alyssa De La Rosa^, Jose Peralta, Jeff Terry, Jorge Gardea-Torresdey*

COURI Symposium Abstracts, Spring 2011

Cerium oxide nanoparticles (NPs) or nanoceria have a high level of UV absorption and antioxidant behavior, making them great candidates for sun screens, beauty products, and in treating cancer and glaucoma. The increased use of these NPs underscores the importance of understanding their environmental fate and toxicity. So far, information about nanoceria toxicity to plants is scarce. The objectives of this study are to determine the effect of CeO2 NPs on soybean (Glycine max) plant growth and monitor their uptake, deposition, and biotransformation. Soybean plants were treated for 14 days in a modified Hoagland solution containing varying concentrations …


Modeling Of Solvent Electrostatic Effects, Jose A. Rodriguez Lopez^, Luis Basurto, Tunna Baruah* Mar 2011

Modeling Of Solvent Electrostatic Effects, Jose A. Rodriguez Lopez^, Luis Basurto, Tunna Baruah*

COURI Symposium Abstracts, Spring 2011

The photo-induced charge-transfer process is fundamental to light harvesting in organic donor-acceptor systems. The process is often enhanced when the system is in a polar solvent. The aim of this project is to create a simple, discrete model containing dipoles that can explain the solvent effects, where only dipole-dipole solvent interaction is considered. The goal is to reduce computational complexities and cost. We create a grid of solvents (water) which mimic the solvent’s density; and put one solute (a light-harvesting triad of β-carotene, porphyrin, and C60) at the grid’s center, keeping the grid points 1.5 times the Van der Waal …


Seismic Study Of Carlsbad, Nm, Steven M. Espinosa^, Aaron A. Velasco* Mar 2011

Seismic Study Of Carlsbad, Nm, Steven M. Espinosa^, Aaron A. Velasco*

COURI Symposium Abstracts, Spring 2011

Since January 1, 2000, there have been numerous earthquakes recorded in the vicinity of Carlsbad, NM.  Importantly, these shallow (10km) earthquakes with magnitudes < 4.3, do not have a fault or system of faults directly mapped to explain these events.  We will be relocating the largest and most recent earthquake, which occurred 25km west of Carlsbad, NM of magnitude 4.1 on March 28, 2010. Data recorded by seismic stations from the USArray, a large National Science Foundation project, and our local Kidd Observatory will be used for this analysis. The use of Standing Order of Data (SOD) allows us access seismograms, and the Seismic Analysis Code (SAC) helps in the analysis of the seismic data.   We will correlate the hypocenters of aftershocks to the main event hypocenter, allowing us to identify the fault plane.  Once a fault plane has been identified, we will begin work on relocating a second event, thereby identifying the responsible faults.  We believe that faulting in this area is related to the Rio Grande Rift extension and can be used as evidence for an active rift.


Detecting Unmarked Graves Using Gpr At The Mescalero Apache Reservation, Stephanie Y. Chavez^, Ashley G. Nauer, Laura Serpa* Mar 2011

Detecting Unmarked Graves Using Gpr At The Mescalero Apache Reservation, Stephanie Y. Chavez^, Ashley G. Nauer, Laura Serpa*

COURI Symposium Abstracts, Spring 2011

In Mescalero, New Mexico, on an Apache Indian Reservation, we were asked to survey the Mescalero Cemetery in order to locate unmarked graves. Back in the late 1800’s, proper documentation of graves was never made. As a result, what is thought to be a new potential burial site is discovered to be an old undocumented grave. Reservation officials have asked us to survey the cemetery and document exact locations of unmarked graves. To achieve this goal, we will use ground penetrating radar (GPR) and a differential global positioning system (DGPS). The collected data will be processed by using EKKO-Mapper and …


Method Development For The Analysis Of Ddt, Ddd, And Dde In Cow Milk, Amanda Parra^, Betty Rocha, Wen-Yee Lee* Mar 2011

Method Development For The Analysis Of Ddt, Ddd, And Dde In Cow Milk, Amanda Parra^, Betty Rocha, Wen-Yee Lee*

COURI Symposium Abstracts, Spring 2011

Organochlorine Pesticides (OCs) are classified as persistent organic pollutants (POPs). They have been found to bioaccumulate in organisms over time. These chemicals tend to attach to fatty tissues in animals and humans, remaining for long periods of time. OCs may be responsible for a vast number of health conditions including neurological disorders, endocrine disruption, reproductive dysfunctions, and possible linkage to cancer.  OCs such as DDT, DDE and DDD are banned, however, they have still been detected in environmental samples worldwide. The main objective of this study is to investigate the presence of DDT, DDE and DDD in cow milk using …


Metal Carbonyl Catalysts For The Transformation Of Silicon Hydrides To Siloxanes In The Presence Of Dmf, Eduardo Cervantes^, Renzo Arias Ugarte, Hemant K. Sharma, Keith H. Pannell* Mar 2011

Metal Carbonyl Catalysts For The Transformation Of Silicon Hydrides To Siloxanes In The Presence Of Dmf, Eduardo Cervantes^, Renzo Arias Ugarte, Hemant K. Sharma, Keith H. Pannell*

COURI Symposium Abstracts, Spring 2011

It has recently been reported that, upon photochemical irradiation, tertiary silanes (R3SiH) react with DMF to form disiloxanes (R3Si-O-SiR3) and Me3N, using the transition metal alkyl complex (η5-C5H5)Fe(CO)2Me as a catalyst. Intermediates of the type R3SiOCH2NMe2 were proposed as the important first step via a hydrosilylation reaction but no evidence was obtained for this suggestion. By changing the catalyst to Mo(CO)6 we have now observed that not only do we form the expected  disiloxanes, but for the first …


Possible Connections Between A Great Earthquake And An Earthquake Sequence: Samoa Islands (8.1) And Vanuatu Islands, Marissa Cameron^, Aaron A. Velasco* Mar 2011

Possible Connections Between A Great Earthquake And An Earthquake Sequence: Samoa Islands (8.1) And Vanuatu Islands, Marissa Cameron^, Aaron A. Velasco*

COURI Symposium Abstracts, Spring 2011

Dynamic triggering describes the possibility that certain earthquakes cause, or ‘trigger’ new earthquakes at great distances. Static triggering is common and is known to cause aftershocks very near to the site, generally within two lengths of the ruptured fault.  Dynamically triggered events can occur at distances beyond two fault lengths, however the mechanism for how this can occur remains unknown. By examining seismic data collected from possible dynamically triggered events, we may gain a better understanding of the mechanisms at work. On September 29, 2009, an earthquake of magnitude 8.1 took place along a 175 km fault rupture in Samoa, …


Are Elevated Nutrient Levels In Arctic Tundra Ponds Due To Permafrost Thawing?, Francisco R. Reyes Jr.^, Vanessa Lougheed* Mar 2011

Are Elevated Nutrient Levels In Arctic Tundra Ponds Due To Permafrost Thawing?, Francisco R. Reyes Jr.^, Vanessa Lougheed*

COURI Symposium Abstracts, Spring 2011

Continued warming of the arctic tundra in northern Alaska can have important ecological implications for freshwater ecosystems. An increased active layer depth can lead to nutrient release from permafrost. Comparisons of water quality parameters from the 1970s and 2008-09 from tundra ponds in Barrow, Alaska indicated an increase in water column Total Phosphorus (TP), Soluble Reactive Phosphorus (SRP), Total Dissolved Phosphorus (TDP) and algal biomass (phytoplankton) over time. We designed an incubation experiment to look at nutrient release rates from permafrost and active layer cores under different warming scenarios. Although water column data have shown an increase in phosphorus species …


Precipitation Accumulation Differentiations In El Paso, Texas And Surrounding Areas, Nessly Torres^, Keith Pannell* Mar 2011

Precipitation Accumulation Differentiations In El Paso, Texas And Surrounding Areas, Nessly Torres^, Keith Pannell*

COURI Symposium Abstracts, Spring 2011

The city of El Paso is built around the Franklin Mountains thus splitting the metropolitan area into four ecologically distinct sections: northwest, west, northeast, and east. However, each segment differs in precipitation accumulation. The intent of this research is to compare current to previous rainfall accumulation data and uncover the factors that have influenced the levels of precipitation around the city over time. Additionally, rainfall accumulation and influencing factors are compared to those of surrounding cities (Las Cruces, NM, Ruidoso NM, Albuquerque, NM, Midland, TX, and Tucson, AZ). Precipitation information was collected using data from the National Weather Service and …


Reduced Activity Of Multiple Endocrine Disrupting Compounds: 17Β-Estradiol And Bisphenol A With A Chemi-Luminescent Assay, Anna C. Ortiz^, Roberto J. De La Torre-Roche, Marc B. Cox, Wen-Yee Lee* Mar 2011

Reduced Activity Of Multiple Endocrine Disrupting Compounds: 17Β-Estradiol And Bisphenol A With A Chemi-Luminescent Assay, Anna C. Ortiz^, Roberto J. De La Torre-Roche, Marc B. Cox, Wen-Yee Lee*

COURI Symposium Abstracts, Spring 2011

The concern about the impacts of endocrine disrupting compounds (EDCs) in the environment has increased recently with their high occurrence in surface waters and sex changes in various aquatic organisms. EDCs include ubiquitously used pharmaceuticals and personal care products, such as soap, detergents, contraceptives, and other medicines, which are released constantly into the environment, in waste water treatment plant effluent. Though toxicological effects of these individual, EDCs have been studied, knowledge on how these chemicals interact together in the environment is very limited. The objective of this project is to study the multi-residue effect of EDCs using a chemi-luminescent yeast …


Estimating Sample Mean Under Interval Uncertainty And Constraint On Sample Varience, Misha Koshelev, Ali Jalal-Kamali, Luc Longpre Jan 2011

Estimating Sample Mean Under Interval Uncertainty And Constraint On Sample Varience, Misha Koshelev, Ali Jalal-Kamali, Luc Longpre

Departmental Technical Reports (CS)

Traditionally, practitioners start a statistical analysis of a given sample x1, … , xn by computing the sample mean E and the sample variance V. The sample values xi usually come from measurements. Measurements are never absolutely accurate and often, the only information that we have about the corresponding measurement errors are the upper bounds Δi on these errors. In such situations, after obtaining the measurement result , the only information that we have about the actual (unknown) value xi of the ith quantity is that xi belongs to the interval …


How To Reconstruct The System's Dynamics By Differentiating Interval-Valued And Set-Valued Functions, Karen Villaverde, Olga Kosheleva Jan 2011

How To Reconstruct The System's Dynamics By Differentiating Interval-Valued And Set-Valued Functions, Karen Villaverde, Olga Kosheleva

Departmental Technical Reports (CS)

To predict the future state of a physical system, we must know the differential equations x = f(x) that describe how this state changes with time. In many practical situations, we can observe individ­ual trajectories x(t). By differentiating these trajectories with respect to time, we can determine the values of f(x) for different states x; if we observe many such trajectories, we can reconstruct the function f( x). However, in many other cases, we do not observe individual systems, we observe a set X of such systems. We can observe how this set X changes, but not how individual …


Cognitive Constructs In Linear Algebra; Metaphors, Metonymies, Modes, Ruben Carrizales Jan 2011

Cognitive Constructs In Linear Algebra; Metaphors, Metonymies, Modes, Ruben Carrizales

Open Access Theses & Dissertations

Analysis focused on the presence of different thinking modes, metonymies, and metaphors found on the interview responses to questions related to linear independence, span, and spanning sets of three students, A12, A22 and C3, taking their first linear algebra course at the college level. Findings provide insight into how first year linear algebra students move from one thinking mode to another, and the kind of metonymies and metaphors are used to construct new knowledge. The main purpose of this research was to discover and analyze the presence of the different modes of thinking and metonymy/metaphors- in the reasoning of these …


The Reactivity Of Potassium Carbanions With Epoxides, Christina Dorado Jan 2011

The Reactivity Of Potassium Carbanions With Epoxides, Christina Dorado

Open Access Theses & Dissertations

The reaction of &alpha-cumylpotassium and cyclohexene oxide produces trans-cumylcyclohexanol in high yield in the presence of excess cumene. Reactions of 1.1 and 2.0 equivalents of cumene with one equivalent of n-butylpotassium to make &alpha-cumylpotassium were shown to take several days to reach a maximum yield in the subsequent reaction of &alpha-cumylpotassium and cyclohexene oxide. Although it was initially hypothesized that the high yield was attributed to the interaction of the potassium with the aromatic rings of the &alpha-cumyl anion and the excess cumene, which was confirmed by molecular modeling studies, these reactions demonstrated that no large excess of …


A Framework For Strategic Sustainable Supply Chain Design, Abril Paola Vazquez Jan 2011

A Framework For Strategic Sustainable Supply Chain Design, Abril Paola Vazquez

Open Access Theses & Dissertations

Sustainable supply chain management has raised interest considerably in recent years; due to environmental concerns from society as well industries. There is a high interest in the industries to solve this problem but many of the frameworks are directed to specific situation or structure. A strategic sustainable supply chain design framework is presented with the purpose of providing many companies, including small and big industries, the means to maintain an eco-friendly operation. These include; industry plants, distribution centers, and retailers.


Patterns And Controls Of Erosion Along The Barrow Environmental Observatory Coastline, Northern Alaska, Adrian Aguirre Jan 2011

Patterns And Controls Of Erosion Along The Barrow Environmental Observatory Coastline, Northern Alaska, Adrian Aguirre

Open Access Theses & Dissertations

With pronounced arctic warming that is linked to loss of sea ice, sea level rise, and land cover change, over the coming decades arctic coastal regions are likely to undergo amongst the most dramatic changes of any ecosystem on Earth. This study used foot surveys and a Differential Global Positioning System (DGPS) to document at a high spatial (horizontal and vertical) resolution, the spatiotemporal dynamics of the eroding bluff along the coastline of the Barrow Environmental Observatory between 2003 and 2009. The coastline consists of an eroding bluff bordered by a shallow muddy lagoon. The coast is protected from strong …


The Isomorphisms Between The Upper And Lower Triangular Matrix Algebras, Zahi Fawaz Jan 2011

The Isomorphisms Between The Upper And Lower Triangular Matrix Algebras, Zahi Fawaz

Open Access Theses & Dissertations

Since matrix equations with triangular matrices are easier to solve, the triangular matrices are very important in mathematics. For instance, the LU decomposition gives an algorithm to decompose any invertible matrix A into two triangular factors: a lower triangle matrix L and an upper triangle matrix U. Moreover, the inverse of a triangular matrix is also triangular. Also the product of two lower triangular matrices produces a lower triangular matrix, the same apply for upper triangular matrices. A lot of important notions, such as the determinant, the eigenvalue problem and many others are easy to handle when we are working …


Development Of A Web-Based Geographic Information System For Arctic Science, George Walker Johnson Jan 2011

Development Of A Web-Based Geographic Information System For Arctic Science, George Walker Johnson

Open Access Theses & Dissertations

Environmental science is a large field of study that requires the acquisition of data for decision making in solving environmental issues. Leveraging desktop geographic information systems (GIS) and web-based GIS (WebGIS) systems for assisting in the problem solving processes can benefit both the research community and policy makers for decision making activities. Ensuring interoperability between desktop, web, and server GIS is essential for maximizing access, sharing and manipulation of data. Interoperability is maximized through the adoption of best practices, use of open standards, and utilization of Spatial Data Infrastructures (SDI). While many of the interoperability challenges such as infrastructure, data …


Asphaltene As Light Harvesting Material In Dye Sensitized Solar Cell, Rajab Emhemed Abujnah Jan 2011

Asphaltene As Light Harvesting Material In Dye Sensitized Solar Cell, Rajab Emhemed Abujnah

Open Access Theses & Dissertations

This Dissertation characterizes the first asphaltene DSSC (dye-sensitized solar cell), in which light to electricity conversion efficiency has improved from 0 % to 1.8 %. Four natural organic asphaltene factions, namely, un-fractionated asphaltene, Fr. 1 Asphaltene, Fr.2 asphaltene, Fr.3 and Fr.4 were extracted and tested for various solar cell parameters of TiO2 based dye-sensitized solar cell DSSC. DSSCs were fabricated using the four individual asphaltene dyes. The photovoltaic performance of the cells was examined by determining the various parameters such as open-circuit voltage, short-circuit current, fill factor, and series resistance. The overall energy conversion efficiency was also measured to correlate …


Dispersion Geochemistry At Different Scales At The Nopal I Deposit, Peña Blanca Uranium District, Chihuahua, Mexico, Katrina Pekar-Carpenter Jan 2011

Dispersion Geochemistry At Different Scales At The Nopal I Deposit, Peña Blanca Uranium District, Chihuahua, Mexico, Katrina Pekar-Carpenter

Open Access Theses & Dissertations

The Nopal I mine in the Peña Blanca Uranium District, Chihuahua, Mexico is a natural analog for the geologic storage of nuclear waste. This dissertation presents data from two sites within Nopal I: 1) the PB-1 core, which was drilled along the extent of uranium mineralization in the Nopal I mine; and 2) a high-grade stockpile boulder from the mineralized Nopal tuff.

The PB-1 core allowed an investigation into the mineralogical and geochemical changes that are important to research on a nuclear waste repository. Five zones were determined to control these changes: 1) Zone 1, the primary uranium mineralization (quartz-uraninite-pyrite-kaolinite-ilmenite); …


Airborne Lead In El Paso, 1977-1999, Ingrid B. Camacho Jan 2011

Airborne Lead In El Paso, 1977-1999, Ingrid B. Camacho

Open Access Theses & Dissertations

Airborne lead is an important component of the biogeochemical make-up of ambient air. Most of the lead emitted to the atmosphere has been in the form of particulate matter.

This study evaluated airborne lead levels in the El Paso airshed at different intervals over the span of three decades between 1977 and 1999. Levels of lead and related metals for a number of years and from a number of sampling stations in El Paso were available from Inductively Coupled Plasma Mass Spectrometry (ICP-MS) analyses previously conducted in Prof. Pingitore's laboratory at UTEP.

Data consisted of some 200 samples, each a …


A Characterization Of Directly Ordered Subspaces Of R^N, Jennifer Del Valle Jan 2011

A Characterization Of Directly Ordered Subspaces Of R^N, Jennifer Del Valle

Open Access Theses & Dissertations

In the finite dimensional ordered vector space Rn, we consider the standard positive cone to be the set Rn+ = {x : x ≥ 0} for an element x in Rn. Given a subspace V of Rn, we define the positive cone of V to be the intersection of V with Rn+. The cone V+ is said to be generating if V = V+ − V+, that is, if any vector v in V can be expressed as the difference of two vectors, v = …