Resource Type

Arsenic chemistry in soils and sediments (open access)

Arsenic chemistry in soils and sediments

Arsenic is a naturally occurring trace element that poses a threat to human and ecosystem health, particularly when incorporated into food or water supplies. The greatest risk imposed by arsenic to human health results from contamination of drinking water, for which the World Health Organization recommends a maximum limit of 10 {micro}g L{sup -1}. Continued ingestion of drinking water having hazardous levels of arsenic can lead to arsenicosis and cancers of the bladder, skin, lungs and kidneys. Unfortunately, arsenic tainted drinking waters are a global threat and presently having a devastating impact on human health within Asia. Nearly 100 million people, for example, are presently consuming drinking water having arsenic concentrations exceeding the World Health Organization's recommended limit (Ahmed et al., 2006). Arsenic contamination of the environment often results from human activities such as mining or pesticide application, but recently natural sources of arsenic have demonstrated a devastating impact on water quality. Arsenic becomes problematic from a health perspective principally when it partitions into the aqueous rather than the solid phase. Dissolved concentrations, and the resulting mobility, of arsenic within soils and sediments are the combined result of biogeochemical processes linked to hydrologic factors. Processes favoring the partitioning of As …
Date: October 15, 2009
Creator: Fendorf, S.; Nico, P.; Kocar, B.D.; Masue, Y. & Tufano, K.J.
System: The UNT Digital Library
Benefits of Parallel I/O in Ab Initio Nuclear Physics Calculations, ICCS 2009 Proceedings (open access)

Benefits of Parallel I/O in Ab Initio Nuclear Physics Calculations, ICCS 2009 Proceedings

Many modern scientific applications rely on highly parallel calculations, which scale to 10's of thousands processors. However, most applications do not concentrate on parallelizing input/output operations. In particular, sequential I/O has been identified as a bottleneck for the highly scalable MFDn (Many Fermion Dynamics for nuclear structure) code performing ab initio nuclear structure calculations. In this paper, we develop interfaces and parallel I/O procedures to use a well-known parallel I/O library in MFDn. As a result, we gain efficient input/output of large datasets along with their portability and ease of use in the downstream processing.
Date: May 20, 2009
Creator: Laghave, Nikhil; Sosonkina, Masha; Maris, Pieter & Vary, James P.
System: The UNT Digital Library
Bridging the Gap in the Chemical Thermodynamic Database for Nuclear Waste Repository: Studies of the Effect of Temperature on Actinide Complexation (open access)

Bridging the Gap in the Chemical Thermodynamic Database for Nuclear Waste Repository: Studies of the Effect of Temperature on Actinide Complexation

Recent results of thermodynamic studies on the complexation of actinides (UO{sub 2}{sup 2+}, NpO{sub 2}{sup +} and Pu{sup 4+}) with F{sup -}, SO{sub 4}{sup 2-} and H{sub 2}PO{sub 4}{sup -}/HPO{sub 4}{sup 2-} at elevated temperatures are reviewed. The data indicate that, for all systems except the 1:1 complexation of Np(V) with HPO{sub 4}{sup 2-}, the complexation of actinides is enhanced by the increase in temperature. The enhancement is primarily due to the increase in the entropy term (T{Delta}S) that exceeds the increase in the enthalpy ({Delta}H) as the temperature is increased. These data bridge the gaps in the chemical thermodynamic database for nuclear waste repository where the temperature could remain significantly higher than 25 C for a long time after the closure of the repository.
Date: December 21, 2009
Creator: Rao, Linfeng; Tian, Guoxin; Xia, Yuanxian; Friese, Judah I.; Zanonato, PierLuigi & Di Bernardo, Plinio
System: The UNT Digital Library
CHAPTER 7. BERYLLIUM ANALYSIS BY NON-PLASMA BASED METHODS (open access)

CHAPTER 7. BERYLLIUM ANALYSIS BY NON-PLASMA BASED METHODS

The most common method of analysis for beryllium is inductively coupled plasma atomic emission spectrometry (ICP-AES). This method, along with inductively coupled plasma mass spectrometry (ICP-MS), is discussed in Chapter 6. However, other methods exist and have been used for different applications. These methods include spectroscopic, chromatographic, colorimetric, and electrochemical. This chapter provides an overview of beryllium analysis methods other than plasma spectrometry (inductively coupled plasma atomic emission spectrometry or mass spectrometry). The basic methods, detection limits and interferences are described. Specific applications from the literature are also presented.
Date: April 20, 2009
Creator: Ekechukwu, A
System: The UNT Digital Library
Chapter 27 -- Breast Cancer Genomics, Section VI, Pathology and Biological Markers of Invasive Breast Cancer (open access)

Chapter 27 -- Breast Cancer Genomics, Section VI, Pathology and Biological Markers of Invasive Breast Cancer

Breast cancer is predominantly a disease of the genome with cancers arising and progressing through accumulation of aberrations that alter the genome - by changing DNA sequence, copy number, and structure in ways that that contribute to diverse aspects of cancer pathophysiology. Classic examples of genomic events that contribute to breast cancer pathophysiology include inherited mutations in BRCA1, BRCA2, TP53, and CHK2 that contribute to the initiation of breast cancer, amplification of ERBB2 (formerly HER2) and mutations of elements of the PI3-kinase pathway that activate aspects of epidermal growth factor receptor (EGFR) signaling and deletion of CDKN2A/B that contributes to cell cycle deregulation and genome instability. It is now apparent that accumulation of these aberrations is a time-dependent process that accelerates with age. Although American women living to an age of 85 have a 1 in 8 chance of developing breast cancer, the incidence of cancer in women younger than 30 years is uncommon. This is consistent with a multistep cancer progression model whereby mutation and selection drive the tumor's development, analogous to traditional Darwinian evolution. In the case of cancer, the driving events are changes in sequence, copy number, and structure of DNA and alterations in chromatin structure or …
Date: June 18, 2009
Creator: Spellman, Paul T.; Heiser, Laura & Gray, Joe W.
System: The UNT Digital Library
Client Handbook: Medicaid Primary Care Case Management Program (open access)

Client Handbook: Medicaid Primary Care Case Management Program

This document provides information on Primary Care Case Management (PCCM) aimed at medicaid clients including changing your primary care provider and explaining the services covered by medicaid.
Date: 2009
Creator: Texas Health and Human Services Commission
System: The Portal to Texas History
Cometabolic bioremediation (open access)

Cometabolic bioremediation

Cometabolic bioremediation is probably the most under appreciated bioremediation strategy currently available. Cometabolism strategies stimulate only indigenous microbes with the ability to degrade the contaminant and cosubstrate e.g. methane, propane, toluene and others. This highly targeted stimulation insures that only those microbes that can degrade the contaminant are targeted, thus reducing amendment costs, well and formation plugging, etc. Cometabolic bioremediation has been used on some of the most recalcitrant contaminants, e.g. PCE, TCE, MTBE, TNT, dioxane, atrazine, etc. Methanotrophs have been demonstrated to produce methane monooxygense, an oxidase that can degrade over 300 compounds. Cometabolic bioremediation also has the advantage of being able to degrade contaminants to trace concentrations, since the biodegrader is not dependent on the contaminant for carbon or energy. Increasingly we are finding that in order to protect human health and the environment that we must remediate to lower and lower concentrations, especially for compounds like endocrine disrupters, thus cometabolism may be the best and maybe the only possibility that we have to bioremediate some contaminants.
Date: February 15, 2009
Creator: Hazen, Terry C.
System: The UNT Digital Library
Cometabolic bioremediation (open access)

Cometabolic bioremediation

This is a report on the comebiotic bioremediation which is the most under-appreciated strategy currently available.
Date: February 15, 2009
Creator: Hazen, Terry C.
System: The UNT Digital Library
Density Functional Theory/A Practical Introduction (open access)

Density Functional Theory/A Practical Introduction

None
Date: January 1, 2009
Creator: Sholl, D. S. & Steckel, J. A.
System: The UNT Digital Library
Diabetes: A Comprehensive Approach (open access)

Diabetes: A Comprehensive Approach

Document outlining diabetes care and statistical information from Texas, as well as organizational information about the Texas Diabetes Council including the agency's strategic plan for 2010-2011.
Date: January 2009
Creator: Texas Diabetes Council
System: The Portal to Texas History
Effortless Healthy Eating. (open access)

Effortless Healthy Eating.

This document is a guide for the Nutrition Education Lesson Code for Effortless Healthy Eating.
Date: September 2009
Creator: Texas. Department of State Health Services.
System: The Portal to Texas History
Electronic Structure Calculations and Adaptation Scheme in Multi-core Computing Environments (open access)

Electronic Structure Calculations and Adaptation Scheme in Multi-core Computing Environments

Multi-core processing environments have become the norm in the generic computing environment and are being considered for adding an extra dimension to the execution of any application. The T2 Niagara processor is a very unique environment where it consists of eight cores having a capability of running eight threads simultaneously in each of the cores. Applications like General Atomic and Molecular Electronic Structure (GAMESS), used for ab-initio molecular quantum chemistry calculations, can be good indicators of the performance of such machines and would be a guideline for both hardware designers and application programmers. In this paper we try to benchmark the GAMESS performance on a T2 Niagara processor for a couple of molecules. We also show the suitability of using a middleware based adaptation algorithm on GAMESS on such a multi-core environment.
Date: May 20, 2009
Creator: Seshagiri, Lakshminarasimhan; Sosonkina, Masha & Zhang, Zhao
System: The UNT Digital Library
Exceptional groups, symmetric spaces and applications (open access)

Exceptional groups, symmetric spaces and applications

In this article we provide a detailed description of a technique to obtain a simple parameterization for different exceptional Lie groups, such as G{sub 2}, F{sub 4} and E{sub 6}, based on their fibration structure. For the compact case, we construct a realization which is a generalization of the Euler angles for SU(2), while for the non compact version of G{sub 2(2)}/SO(4) we compute the Iwasawa decomposition. This allows us to obtain not only an explicit expression for the Haar measure on the group manifold, but also for the cosets G{sub 2}/SO(4), G{sub 2}/SU(3), F{sub 4}/Spin(9), E{sub 6}/F{sub 4} and G{sub 2(2)}/SO(4) that we used to find the concrete realization of the general element of the group. Moreover, as a by-product, in the simplest case of G{sub 2}/SO(4), we have been able to compute an Einstein metric and the vielbein. The relevance of these results in physics is discussed.
Date: March 31, 2009
Creator: Cerchiai, Bianca L. & Cacciatori, Sergio L.
System: The UNT Digital Library
Experimental Mathematics and Computational Statistics (open access)

Experimental Mathematics and Computational Statistics

The field of statistics has long been noted for techniques to detect patterns and regularities in numerical data. In this article we explore connections between statistics and the emerging field of 'experimental mathematics'. These includes both applications of experimental mathematics in statistics, as well as statistical methods applied to computational mathematics.
Date: April 30, 2009
Creator: Bailey, David H. & Borwein, Jonathan M.
System: The UNT Digital Library
FCC Record, Volume 24, No. 1, Pages 1 to 856, January 2 - January 16, 2009 (open access)

FCC Record, Volume 24, No. 1, Pages 1 to 856, January 2 - January 16, 2009

Biweekly, comprehensive compilation of decisions, reports, public notices, and other documents of the U.S. Federal Communications Commission.
Date: January 2009
Creator: United States. Federal Communications Commission.
System: The UNT Digital Library
FCC Record, Volume 24, No. 2, Pages 857 to 1611, January 19 - February 13, 2009 (open access)

FCC Record, Volume 24, No. 2, Pages 857 to 1611, January 19 - February 13, 2009

Biweekly, comprehensive compilation of decisions, reports, public notices, and other documents of the U.S. Federal Communications Commission.
Date: February 2009
Creator: United States. Federal Communications Commission.
System: The UNT Digital Library
FCC Record, Volume 24, No. 3, Pages 1612 to 2571, February 16 - February 26, 2009 (open access)

FCC Record, Volume 24, No. 3, Pages 1612 to 2571, February 16 - February 26, 2009

Biweekly, comprehensive compilation of decisions, reports, public notices, and other documents of the U.S. Federal Communications Commission.
Date: February 2009
Creator: United States. Federal Communications Commission.
System: The UNT Digital Library
FCC Record, Volume 24, No. 4, Pages 2572 to 3518, February 27 - March 20, 2009 (open access)

FCC Record, Volume 24, No. 4, Pages 2572 to 3518, February 27 - March 20, 2009

Biweekly, comprehensive compilation of decisions, reports, public notices, and other documents of the U.S. Federal Communications Commission.
Date: March 2009
Creator: United States. Federal Communications Commission.
System: The UNT Digital Library
FCC Record, Volume 24, No. 5, Pages 3519 to 4422, March 23 - April 10, 2009 (open access)

FCC Record, Volume 24, No. 5, Pages 3519 to 4422, March 23 - April 10, 2009

Biweekly, comprehensive compilation of decisions, reports, public notices, and other documents of the U.S. Federal Communications Commission.
Date: April 2009
Creator: United States. Federal Communications Commission.
System: The UNT Digital Library
FCC Record, Volume 24, No. 6, Pages 4423 to 5282, April 13 - May 1, 2009 (open access)

FCC Record, Volume 24, No. 6, Pages 4423 to 5282, April 13 - May 1, 2009

Biweekly, comprehensive compilation of decisions, reports, public notices, and other documents of the U.S. Federal Communications Commission.
Date: May 2009
Creator: United States. Federal Communications Commission.
System: The UNT Digital Library
FCC Record, Volume 24, No. 7, Pages 5283 to 6184, May 4 - May 22, 2009 (open access)

FCC Record, Volume 24, No. 7, Pages 5283 to 6184, May 4 - May 22, 2009

Biweekly, comprehensive compilation of decisions, reports, public notices, and other documents of the U.S. Federal Communications Commission.
Date: May 2009
Creator: United States. Federal Communications Commission.
System: The UNT Digital Library
FCC Record, Volume 24, No. 8, Pages 6185 to 7016, Supplement (2009) (open access)

FCC Record, Volume 24, No. 8, Pages 6185 to 7016, Supplement (2009)

Biweekly, comprehensive compilation of decisions, reports, public notices, and other documents of the U.S. Federal Communications Commission.
Date: 2009
Creator: United States. Federal Communications Commission.
System: The UNT Digital Library
FCC Record, Volume 24, No. 9, Pages 7017 to 7967, May 26 - June 12, 2009 (open access)

FCC Record, Volume 24, No. 9, Pages 7017 to 7967, May 26 - June 12, 2009

Biweekly, comprehensive compilation of decisions, reports, public notices, and other documents of the U.S. Federal Communications Commission.
Date: June 2009
Creator: United States. Federal Communications Commission.
System: The UNT Digital Library
FCC Record, Volume 24, No. 10, Pages 7968 to 8784, June 15 - June 26, 2009 (open access)

FCC Record, Volume 24, No. 10, Pages 7968 to 8784, June 15 - June 26, 2009

Biweekly, comprehensive compilation of decisions, reports, public notices, and other documents of the U.S. Federal Communications Commission.
Date: June 2009
Creator: United States. Federal Communications Commission.
System: The UNT Digital Library