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Ion exchange phenomena (open access)

Ion exchange phenomena

Ion exchange phenomena involve the population of readily exchangeable ions, the subset of adsorbed solutes that balance the intrinsic surface charge and can be readily replaced by major background electrolyte ions (Sposito, 2008). These phenomena have occupied a central place in soil chemistry research since Way (1850) first showed that potassium uptake by soils resulted in the release of an equal quantity of moles of charge of calcium and magnesium. Ion exchange phenomena are now routinely modeled in studies of soil formation (White et al., 2005), soil reclamation (Kopittke et al., 2006), soil fertilitization (Agbenin and Yakubu, 2006), colloidal dispersion/flocculation (Charlet and Tournassat, 2005), the mechanics of argillaceous media (Gajo and Loret, 2007), aquitard pore water chemistry (Tournassat et al., 2008), and groundwater (Timms and Hendry, 2007; McNab et al., 2009) and contaminant hydrology (Chatterjee et al., 2008; van Oploo et al., 2008; Serrano et al., 2009).
Date: May 1, 2011
Creator: Bourg, I.C. & Sposito, G.
System: The UNT Digital Library
Bioananalytics of Human Microdosing (open access)

Bioananalytics of Human Microdosing

None
Date: May 2, 2011
Creator: Buchholz, B. A.; Sarachine Falso, M. J.; Stewart, B. J.; Haack, K. W.; Ognibene, T. J.; Salazar Quintero, G. A. et al.
System: The UNT Digital Library
Establishing Natural Product Content with the Natural Radiocarbon Signature (open access)

Establishing Natural Product Content with the Natural Radiocarbon Signature

None
Date: May 7, 2010
Creator: Buchholz, B. A.; Sarachine, M. J. & Zermeno, P.
System: The UNT Digital Library
Chapter 11. Community analysis-based methods (open access)

Chapter 11. Community analysis-based methods

Microbial communities are each a composite of populations whose presence and relative abundance in water or other environmental samples are a direct manifestation of environmental conditions, including the introduction of microbe-rich fecal material and factors promoting persistence of the microbes therein. As shown by culture-independent methods, different animal-host fecal microbial communities appear distinctive, suggesting that their community profiles can be used to differentiate fecal samples and to potentially reveal the presence of host fecal material in environmental waters. Cross-comparisons of microbial communities from different hosts also reveal relative abundances of genetic groups that can be used to distinguish sources. In increasing order of their information richness, several community analysis methods hold promise for MST applications: phospholipid fatty acid (PLFA) analysis, denaturing gradient gel electrophoresis (DGGE), terminal restriction fragment length polymorphism (TRFLP), cloning/sequencing, and PhyloChip. Specific case studies involving TRFLP and PhyloChip approaches demonstrate the ability of community-based analyses of contaminated waters to confirm a diagnosis of water quality based on host-specific marker(s). The success of community-based MST for comprehensively confirming fecal sources relies extensively upon using appropriate multivariate statistical approaches. While community-based MST is still under evaluation and development as a primary diagnostic tool, results presented herein demonstrate its promise. …
Date: May 1, 2010
Creator: Cao, Y.; Wu, C. H.; Andersen, G. L. & Holden, P. A.
System: The UNT Digital Library
Tax Information: Franchise Tax Reporting Tips for Combined Groups (open access)

Tax Information: Franchise Tax Reporting Tips for Combined Groups

This document provides tips for combined groups on franchise tax reporting.
Date: May 2012
Creator: Combs, Susan
System: The Portal to Texas History
Fit For 50+, Catalog for Denton Senior Center: May 2018 (open access)

Fit For 50+, Catalog for Denton Senior Center: May 2018

Catalog of seasonal activities offered by City of Denton Parks and Recreation and the Denton Senior Center for adults aged 50+, including special events, programs, and classes. Some issues also include articles or messages from staffmembers about topics of interest to seniors.
Date: May 2018
Creator: Denton Senior Center
System: The Portal to Texas History
DEVELOPMENT AND SELECTION OF IONIC LIQUID ELECTROLYTES FOR HYDROXIDE CONDUCTING POLYBENZIMIDAZOLE MEMBRANES IN ALKALINE FUEL CELLS (open access)

DEVELOPMENT AND SELECTION OF IONIC LIQUID ELECTROLYTES FOR HYDROXIDE CONDUCTING POLYBENZIMIDAZOLE MEMBRANES IN ALKALINE FUEL CELLS

Alkaline fuel cell (AFC) operation is currently limited to specialty applications such as low temperatures and pure H{sub 2}/O{sub 2} due to the corrosive nature of the electrolyte and formation of carbonates. AFCs are the cheapest and potentially most efficient (approaching 70%) fuel cells. The fact that non-Pt catalysts can be used, makes them an ideal low cost alternative for power production. The anode and cathode are separated by and solid electrolyte or alkaline porous media saturated with KOH. However, CO{sub 2} from the atmosphere or fuel feed severely poisons the electrolyte by forming insoluble carbonates. The corrosivity of KOH (electrolyte) limits operating temperatures to no more than 80�C. This chapter examines the development of ionic liquids electrolytes that are less corrosive, have higher operating temperatures, do not chemically bond to CO{sub 2}, and enable alternative fuels. Work is detailed on the IL selection and characterization as well as casting methods within the polybenzimidazole based solid membrane. This approach is novel as it targets the root of the problem (the electrolyte) unlike other current work in alkaline fuel cells which focus on making the fuel cell components more durable.
Date: May 1, 2012
Creator: Fox, E.
System: The UNT Digital Library
CHAPTER 5-RADIOACTIVE WASTE MANAGEMENT (open access)

CHAPTER 5-RADIOACTIVE WASTE MANAGEMENT

The ore pitchblende was discovered in the 1750's near Joachimstal in what is now the Czech Republic. Used as a colorant in glazes, uranium was identified in 1789 as the active ingredient by chemist Martin Klaproth. In 1896, French physicist Henri Becquerel studied uranium minerals as part of his investigations into the phenomenon of fluorescence. He discovered a strange energy emanating from the material which he dubbed 'rayons uranique.' Unable to explain the origins of this energy, he set the problem aside. About two years later, a young Polish graduate student was looking for a project for her dissertation. Marie Sklodowska Curie, working with her husband Pierre, picked up on Becquerel's work and, in the course of seeking out more information on uranium, discovered two new elements (polonium and radium) which exhibited the same phenomenon, but were even more powerful. The Curies recognized the energy, which they now called 'radioactivity,' as something very new, requiring a new interpretation, new science. This discovery led to what some view as the 'golden age of nuclear science' (1895-1945) when countries throughout Europe devoted large resources to understand the properties and potential of this material. By World War II, the potential to harness this …
Date: May 5, 2010
Creator: Marra, J.
System: The UNT Digital Library
METALLIC AND HYBRID NANOSTRUCTURES: FUNDAMENTALS AND APPLICATIONS (open access)

METALLIC AND HYBRID NANOSTRUCTURES: FUNDAMENTALS AND APPLICATIONS

This book chapter presents an overview of research conducted in our laboratory on preparation, optical and physico-chemical properties of metallic and nanohybrid materials. Metallic nanoparticles, particularly gold, silver, platinum or a combination of those are the main focus of this review manuscript. These metallic nanoparticles were further functionalized and used as templates for creation of complex and ordered nanomaterials with tailored and tunable structural, optical, catalytic and surface properties. Controlling the surface chemistry on/off metallic nanoparticles allows production of advanced nanoarchitectures. This includes coupled or encapsulated core-shell geometries, nano-peapods, solid or hollow, monometallic/bimetallic, hybrid nanoparticles. Rational assemblies of these nanostructures into one-, two- and tridimensional nano-architectures is described and analyzed. Their sensing, environmental and energy related applications are reviewed.
Date: May 2, 2012
Creator: Murph, S.
System: The UNT Digital Library
Composite Materials under Extreme Radiation and Temperature Environments of the Next Generation Nuclear Reactors (open access)

Composite Materials under Extreme Radiation and Temperature Environments of the Next Generation Nuclear Reactors

In the nuclear energy renaissance, driven by fission reactor concepts utilizing very high temperatures and fast neutron spectra, materials with enhanced performance that exceeds are expected to play a central role. With the operating temperatures of the Generation III reactors bringing the classical reactor materials close to their performance limits there is an urgent need to develop and qualify new alloys and composites. Efforts have been focused on the intricate relations and the high demands placed on materials at the anticipated extreme states within the next generation fusion and fission reactors which combine high radiation fluxes, elevated temperatures and aggressive environments. While nuclear reactors have been in operation for several decades, the structural materials associated with the next generation options need to endure much higher temperatures (1200 C), higher neutron doses (tens of displacements per atom, dpa), and extremely corrosive environments, which are beyond the experience on materials accumulated to-date. The most important consideration is the performance and reliability of structural materials for both in-core and out-of-core functions. While there exists a great body of nuclear materials research and operating experience/performance from fission reactors where epithermal and thermal neutrons interact with materials and alter their physio-mechanical properties, a process that …
Date: May 1, 2011
Creator: Simos, N.
System: The UNT Digital Library
16th Annual Advanced Insurance Law Course (open access)

16th Annual Advanced Insurance Law Course

Document containing resources relevant to Insurance Law including seminars, the Texas Lawyer's Creed, Paralegal Creed, and advertisements relevant to legal professionals.
Date: 2019-05~
Creator: State Bar of Texas
System: The Portal to Texas History
Texas Board of Professional Geoscientists Strategic Plan: Fiscal Years 2015-2019 (open access)

Texas Board of Professional Geoscientists Strategic Plan: Fiscal Years 2015-2019

Strategic plan of the Board of Professional Geoscientists for fiscal years 2015-2019 outlining the agency's mission, previous activities, and goals for the next five years.
Date: May 23, 2014
Creator: Texas Board of Professional Geoscientists
System: The Portal to Texas History
Claiming No Discharge from Stormwater Permit Requirements (open access)

Claiming No Discharge from Stormwater Permit Requirements

This document is for owners and operators of industrial facilities that are subject to the Texas Pollution Discharge System (TPDES) Multi-Sector General Permit (MSGP). This guidance will help you understand what a "No Discharge" claim is, and what type of documentation you can use to demonstrate a claim.
Date: May 2018
Creator: Texas Commission on Environmental Quality
System: The Portal to Texas History
A Guide to Obtaining Permits in Rule Authorizations in STEERS ePermits (open access)

A Guide to Obtaining Permits in Rule Authorizations in STEERS ePermits

Guide describing regulations for STEERS ePermits.
Date: May 2019
Creator: Texas Commission on Environmental Quality
System: The Portal to Texas History
Review and Reporting of COC Concentration Data under TRRP (open access)

Review and Reporting of COC Concentration Data under TRRP

This document provides the procedures for review and reporting of chemical of concern (COC) concentration data under the Texas Risk Reduction Program (TRRP).
Date: May 2010
Creator: Texas Commission on Environmental Quality. Remediation Division.
System: The Portal to Texas History
Surface Water Quality Monitoring Procedures, Volume 2: Methods for Collecting and Analyzing Biological Assemblage and Habitat Data (open access)

Surface Water Quality Monitoring Procedures, Volume 2: Methods for Collecting and Analyzing Biological Assemblage and Habitat Data

Procedural manual for collecting and analyzing biological assemblage and habitat data as a part of surface water quality monitoring.
Date: May 2014
Creator: Texas Commission on Environmental Quality. Water Quality Planning Division.
System: The Portal to Texas History
Fees, Standards, and Reporting Requirements for Public Water Systems (open access)

Fees, Standards, and Reporting Requirements for Public Water Systems

This guidance document is revised to incorporate the most current rule language as of November 2011.
Date: May 2012
Creator: Texas Commission on Environmental Quality. Water Supply Division.
System: The Portal to Texas History
Campaign Finance Guide for Judicial Candidates and Officeholders (open access)

Campaign Finance Guide for Judicial Candidates and Officeholders

This guide is a summary of the judicial campaign finance regulations set out in title 15 of the Election Code and in the rules adopted by the Texas Ethics Commission.
Date: May 22, 2013
Creator: Texas Ethics Commission
System: The Portal to Texas History
Catalog of Texas Tech University, 2011-2012, Undergraduate and Graduate (open access)

Catalog of Texas Tech University, 2011-2012, Undergraduate and Graduate

Catalog of undergraduate and graduate courses offered by Texas Tech University for the year 2011-2012, as well as general information about the university, programs, and policies.
Date: May 2011
Creator: Texas Tech University
System: The Portal to Texas History
Catalog of Texas Tech University, 2012-2013, Undergraduate and Graduate (open access)

Catalog of Texas Tech University, 2012-2013, Undergraduate and Graduate

Catalog of undergraduate and graduate courses offered by Texas Tech University for the year 2012-2013, as well as general information about the university, programs, and policies.
Date: May 2012
Creator: Texas Tech University
System: The Portal to Texas History
Catalog of Texas Tech University, 2013-2014, Unergraduate and Graduate (open access)

Catalog of Texas Tech University, 2013-2014, Unergraduate and Graduate

Catalog of undergraduate and graduate courses offered by Texas Tech University for the year 2013-2014, as well as general information about the university, programs, and policies.
Date: May 2013
Creator: Texas Tech University
System: The Portal to Texas History
Catalog of Texas Tech University, 2015-2016, Undergraduate and Graduate (open access)

Catalog of Texas Tech University, 2015-2016, Undergraduate and Graduate

Catalog of undergraduate and graduate courses offered by Texas Tech University for the year 2015-2016, as well as general information about the university, programs, and policies.
Date: May 2015
Creator: Texas Tech University
System: The Portal to Texas History
Catalog of Texas Tech University, 2017-2018, Undergraduate and Graduate (open access)

Catalog of Texas Tech University, 2017-2018, Undergraduate and Graduate

Catalog of undergraduate and graduate courses offered by Texas Tech University for the year 2017-2018, as well as general information about the university, programs, and policies.
Date: May 2017
Creator: Texas Tech University
System: The Portal to Texas History
Catalog of Texas Tech University, 2018-2019, Undergraduate and Graduate (open access)

Catalog of Texas Tech University, 2018-2019, Undergraduate and Graduate

Catalog of undergraduate and graduate courses offered by Texas Tech University for the year 2018-2019, as well as general information about the university, programs, and policies.
Date: May 2018
Creator: Texas Tech University
System: The Portal to Texas History