Colloid-Facilitated Transport of Radionuclides through the Vadose Zone (open access)

Colloid-Facilitated Transport of Radionuclides through the Vadose Zone

The main purpose of this project was to advance the basic scientific understanding of colloid and colloid-facilitated Cs transport of radionuclides in the vadose zone. We focused our research on the hydrological and geochemical conditions beneath the leaking waste tanks at the USDOE Hanford reservation. Specific objectives were (1) to determine the lability and thermodynamic stability of colloidal materials, which form after reacting Hanford sediments with simulated Hanford Tank Waste, (2) to characterize the interactions between colloidal particles and contaminants, i.e., Cs and Eu, (3) to determine the potential of Hanford sediments for \textit{in situ} mobilization of colloids, (4) to evaluate colloid-facilitated radionuclide transport through sediments under unsaturated flow, (5) to implement colloid-facilitated contaminant transport mechanisms into a transport model, and (6) to improve conceptual characterization of colloid-contaminant-soil interactions and colloid-facili\-tated transport for clean-up procedures and long-term risk assessment. We have previously shown that upon contact with simulated waste tank solutions, Hanford sediments change their mineralogical composition. Certain minerals, i.e., quartz, smectite, and kaolinite, are partially dissolved, and new mineral phases, i.e., the feldspathoids cancrinite and sodalite, are formed. We have characterized these mineral transformations and clarified the mineral transformation pathways. The new minerals were mainly in the colloidal size …
Date: November 21, 2006
Creator: Flury, Markus; Harsh, James B.; McCarthy, John F.; Lichtner, Peter C. & Zachara, John M.
Object Type: Report
System: The UNT Digital Library
Cherokeean Herald (Rusk, Tex.), Vol. 157, No. 18, Ed. 1 Wednesday, June 21, 2006 (open access)

Cherokeean Herald (Rusk, Tex.), Vol. 157, No. 18, Ed. 1 Wednesday, June 21, 2006

Weekly newspaper from Rusk, Texas that includes local, state and national news along with extensive advertising.
Date: June 21, 2006
Creator: Whitehead, Marie
Object Type: Newspaper
System: The Portal to Texas History
[Clipping: Politicians faulted on donor law] (open access)

[Clipping: Politicians faulted on donor law]

Clipping of an article about a law requiring public disclosure of the occupations of major campaign donors.
Date: June 21, 2006
Creator: The Dallas Morning News
Object Type: Newspaper
System: The UNT Digital Library
The Grandview Tribune (Grandview, Tex.), Vol. 111, No. 45, Ed. 1 Friday, July 21, 2006 (open access)

The Grandview Tribune (Grandview, Tex.), Vol. 111, No. 45, Ed. 1 Friday, July 21, 2006

Weekly newspaper from Grandview, Texas that includes local, state, and national news along with advertising.
Date: July 21, 2006
Creator: Beck-Adams, Candie
Object Type: Newspaper
System: The Portal to Texas History
Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 91, No. 296, Ed. 1 Monday, August 21, 2006 (open access)

Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 91, No. 296, Ed. 1 Monday, August 21, 2006

Daily newspaper from Sapulpa, Oklahoma that includes local, state, and national news along with advertising.
Date: August 21, 2006
Creator: Mattox, Jami
Object Type: Newspaper
System: The Gateway to Oklahoma History
Archer County Advocate (Holliday, Tex.), Vol. 4, No. 37, Ed. 1 Thursday, December 21, 2006 (open access)

Archer County Advocate (Holliday, Tex.), Vol. 4, No. 37, Ed. 1 Thursday, December 21, 2006

Weekly newspaper from Holliday, Texas that includes local, state, and national news along with advertising.
Date: December 21, 2006
Creator: Stevens, Charlotte
Object Type: Newspaper
System: The Portal to Texas History
Comanche Chief (Comanche, Tex.), No. 34, Ed. 1 Thursday, December 21, 2006 (open access)

Comanche Chief (Comanche, Tex.), No. 34, Ed. 1 Thursday, December 21, 2006

Weekly newspaper from Comanche, Texas that includes local, state, and national news along with advertising.
Date: December 21, 2006
Creator: Wilkerson, James C., III
Object Type: Newspaper
System: The Portal to Texas History
The Llano News (Llano, Tex.), Vol. 118, No. 38, Ed. 1 Wednesday, June 21, 2006 (open access)

The Llano News (Llano, Tex.), Vol. 118, No. 38, Ed. 1 Wednesday, June 21, 2006

Weekly newspaper from Llano, Texas that includes local, state, and national news along with advertising.
Date: June 21, 2006
Creator: Stephenson, Jimmy
Object Type: Newspaper
System: The Portal to Texas History
Coupled Geochemical and Hydrological Processes Governing the Fate and Transport of Radionuclides and Toxic Metals Beneath the Hanford Tank Farms (open access)

Coupled Geochemical and Hydrological Processes Governing the Fate and Transport of Radionuclides and Toxic Metals Beneath the Hanford Tank Farms

The goal of this research was to provide an improved understanding and predictive capability of coupled hydrological and geochemical mechanisms that are responsible for the accelerated migration and immobilization of radionuclides and toxic metals in the badose zone beneath the Hanford Tank Farms.
Date: July 21, 2006
Creator: Fendorf, Scott & Jardine, Phil
Object Type: Report
System: The UNT Digital Library
Věstník (Temple, Tex.), Vol. 94, No. 25, Ed. 1 Wednesday, June 21, 2006 (open access)

Věstník (Temple, Tex.), Vol. 94, No. 25, Ed. 1 Wednesday, June 21, 2006

Weekly Czech and English language newspaper from Temple, Texas published as the official organ of the Slavonic Benevolent Order of the State of Texas that includes news of interest to members along with advertising.
Date: June 21, 2006
Creator: Zavodny, Melanie
Object Type: Newspaper
System: The Portal to Texas History
Royalty Revenues: Total Revenues Have Not Increased at the Same Pace as Rising Oil and Natural Gas Prices due to Decreasing Production Sold (open access)

Royalty Revenues: Total Revenues Have Not Increased at the Same Pace as Rising Oil and Natural Gas Prices due to Decreasing Production Sold

Correspondence issued by the Government Accountability Office with an abstract that begins "In fiscal year 2005, federal and Native American lands supplied about 35 percent of the oil and 26 percent of the natural gas produced in the United States. Companies that lease these lands to produce oil and natural gas pay royalties to the Department of the Interior's Minerals Management Service (MMS) based on a percentage (the royalty rate) of the cash value of the oil and natural gas produced and sold. As an alternative to collecting cash royalty payments, MMS has the option to take a percentage of the actual oil and natural gas produced (referred to as "taking royalties in kind") and selling it themselves or using it for other purposes, such as filling the nation's Strategic Petroleum Reserve (SPR). MMS reported collecting $7.4 billion in fiscal year 2001 and $8 billion in fiscal year 2005 in cash royalty payments and in revenue from its own royalty-in-kind sales of oil and natural gas. While these total royalty revenues increased by about 8 percent from 2001 to 2005, oil and natural gas prices rose substantially more--about 90 percent for oil and 30 percent for natural gas. Consequently, Congress …
Date: June 21, 2006
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
De Leon Free Press (De Leon, Tex.), Vol. 116, No. 25, Ed. 1 Thursday, December 21, 2006 (open access)

De Leon Free Press (De Leon, Tex.), Vol. 116, No. 25, Ed. 1 Thursday, December 21, 2006

Weekly newspaper from De Leon, Texas that includes local, state, and national news along with advertising.
Date: December 21, 2006
Creator: Kestner, Laura
Object Type: Newspaper
System: The Portal to Texas History
Screening of Potential Remediation Methods for the 200-BP-5 Operable Unit at the Hanford Site (open access)

Screening of Potential Remediation Methods for the 200-BP-5 Operable Unit at the Hanford Site

A screening-level evaluation of potential remediation methods for application to the contaminants of concern (COC) in the 200-BP-5 Operable Unit at the Hanford Site was conducted based on the methods outlined in the Guidance for Conducting Remedial Investigations and Feasibility Studies under CERCLA Interim Final (EPA 1988). The scope of this screening was to identify the most promising remediation methods for use in the more detailed analysis of remediation alternatives that will be conducted as part of the full feasibility study. The screening evaluation was conducted for the primary COC (potential major risk drivers) identified in the groundwater sampling and analysis plan for the operable unit (DOE/RL-2001-49, Rev. 1) with additions.
Date: September 21, 2006
Creator: Truex, Michael J.; Dresel, P. EVAN; Nimmons, Michael J. & Johnson, Christian D.
Object Type: Report
System: The UNT Digital Library
Influence of Dust Composition on Cloud Droplet Formation (open access)

Influence of Dust Composition on Cloud Droplet Formation

Previous studies suggest that interactions between dust particles and clouds are significant; yet the conditions where dust particles can serve as cloud condensation nuclei (CCN) are uncertain. Since major dust components are insoluble, the CCN activity of dust strongly depends on the presence of minor components. However, many minor components measured in dust particles are overlooked in cloud modeling studies. Some of these compounds are believed to be products of heterogeneous reactions involving carbonates. In this study, we calculate Kohler curves (modified for slightly soluble substances) for dust particles containing small amounts of K{sup +}, Mg{sup 2+}, or Ca{sup 2+} compounds to estimate the conditions where reacted and unreacted dust can activate. We also use an adiabatic parcel model to evaluate the influence of dust particles on cloud properties via water competition. Based on their bulk solubilities, K{sup +} compounds, MgSO{sub 4} x 7H{sub 2}O, Mg(NO{sub 3}){sub 2} x 6H{sub 2}O, and Ca(NO{sub 3}){sub 2} x 4H{sub 2}O are classified as highly soluble substances, which enable activation of fine dust. Slightly soluble gypsum and MgSO{sub 3} x 6H{sub 2}O, which may form via heterogeneous reactions involving carbonates, enable activation of particles with diameters between about 0.6 and 2 mm under …
Date: August 21, 2006
Creator: Kelly, J. T.; Chuang, C. C. & Wexler, A. S.
Object Type: Article
System: The UNT Digital Library
Predicting dissolution patterns in variable aperture fractures: 1. Development and evaluation of an enhanced depth-averaged computational model (open access)

Predicting dissolution patterns in variable aperture fractures: 1. Development and evaluation of an enhanced depth-averaged computational model

Water-rock interactions within variable-aperture fractures can lead to dissolution of fracture surfaces and local alteration of fracture apertures, potentially transforming the transport properties of the fracture over time. Because fractures often provide dominant pathways for subsurface flow and transport, developing models that effectively quantify the role of dissolution on changing transport properties over a range of scales is critical to understanding potential impacts of natural and anthropogenic processes. Dissolution of fracture surfaces is controlled by surface-reaction kinetics and transport of reactants and products to and from the fracture surfaces. We present development and evaluation of a depth-averaged model of fracture flow and reactive transport that explicitly calculates local dissolution-induced alterations in fracture apertures. The model incorporates an effective mass transfer relationship that implicitly represents the transition from reaction-limited dissolution to transport-limited dissolution. We evaluate the model through direct comparison to previously reported physical experiments in transparent analog fractures fabricated by mating an inert, transparent rough surface with a smooth single crystal of potassium dihydrogen phosphate (KDP), which allowed direct measurement of fracture aperture during dissolution experiments using well-established light transmission techniques [Detwiler, et al., 2003]. Comparison of experiments and simulations at different flow rates demonstrate the relative impact of the …
Date: April 21, 2006
Creator: Detwiler, R L & Rajaram, H
Object Type: Article
System: The UNT Digital Library
The Panola Watchman (Carthage, Tex.), Vol. 133, No. [49], Ed. 1 Wednesday, June 21, 2006 (open access)

The Panola Watchman (Carthage, Tex.), Vol. 133, No. [49], Ed. 1 Wednesday, June 21, 2006

Semiweekly newspaper from Carthage, Texas that includes local, state, and national news along with advertising.
Date: June 21, 2006
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
The Albany News (Albany, Tex.), Vol. 131, No. 30, Ed. 1 Thursday, December 21, 2006 (open access)

The Albany News (Albany, Tex.), Vol. 131, No. 30, Ed. 1 Thursday, December 21, 2006

Weekly newspaper from Albany, Texas that includes local, county, and state news along with extensive advertising.
Date: December 21, 2006
Creator: Lucas, Melinda L.
Object Type: Newspaper
System: The Portal to Texas History
Outer Continental Shelf: Debate Over Oil and Gas Leasing and Revenue Sharing (open access)

Outer Continental Shelf: Debate Over Oil and Gas Leasing and Revenue Sharing

None
Date: July 21, 2006
Creator: unknown
Object Type: Report
System: The UNT Digital Library
ANWR Leasing Revenue Estimates (open access)

ANWR Leasing Revenue Estimates

This report includes Arctic National Wildlife Refuge(ANWR) Leasing Revenue Estimates.
Date: April 21, 2006
Creator: Gelb, Bernard A.
Object Type: Report
System: The UNT Digital Library
The Express-Star (Chickasha, Okla.), Ed. 1 Tuesday, March 21, 2006 (open access)

The Express-Star (Chickasha, Okla.), Ed. 1 Tuesday, March 21, 2006

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date: March 21, 2006
Creator: Bush, Kent
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Grandview Tribune (Grandview, Tex.), Vol. 111, No. 33, Ed. 1 Friday, April 21, 2006 (open access)

The Grandview Tribune (Grandview, Tex.), Vol. 111, No. 33, Ed. 1 Friday, April 21, 2006

Weekly newspaper from Grandview, Texas that includes local, state, and national news along with advertising.
Date: April 21, 2006
Creator: Beck-Adams, Candie
Object Type: Newspaper
System: The Portal to Texas History
Liberia's Post-War Recovery: Key Issues and Developments (open access)

Liberia's Post-War Recovery: Key Issues and Developments

This report covers recent developments in Liberia, a small, poor West African country which began a post-conflict transition process to achieve enduring peace, socio-economic reconstruction and democratic governance.
Date: March 21, 2006
Creator: Cook, Nicolas
Object Type: Report
System: The UNT Digital Library
Yoakum Herald-Times (Yoakum, Tex.), Vol. 114, No. 25, Ed. 1 Wednesday, June 21, 2006 (open access)

Yoakum Herald-Times (Yoakum, Tex.), Vol. 114, No. 25, Ed. 1 Wednesday, June 21, 2006

Weekly newspaper from Yoakum, Texas that includes local, state, and national news along with advertising.
Date: June 21, 2006
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
The Clifton Record (Clifton, Tex.), Vol. 111, No. 16, Ed. 1 Friday, April 21, 2006 (open access)

The Clifton Record (Clifton, Tex.), Vol. 111, No. 16, Ed. 1 Friday, April 21, 2006

Weekly newspaper from Clifton, Texas that includes local, state, and national news along with advertising.
Date: April 21, 2006
Creator: Smith, W. Leon
Object Type: Newspaper
System: The Portal to Texas History