Partner
UNT Libraries Special Collections
451
UNT Libraries Government Documents Department
338
UNT College of Merchandising, Hospitality and Tourism
134
UNT Libraries
47
Oklahoma Historical Society
46
National Museum of the Pacific War/Admiral Nimitz Foundation
22
UNT Press
15
UNT Music Library
13
Sweetwater/Nolan County City-County Library
10
Sterling Municipal Library
9
45 More
Collection
The Black Academy of Arts and Letters Records
431
Office of Scientific & Technical Information Technical Reports
176
Documenting Plate Waste in Middle School Cafeterias Using Digital Still Photography
134
Texas Digital Newspaper Program
132
Congressional Research Service Reports
79
Government Accountability Office Reports
56
Oklahoma Digital Newspaper Program
51
The Greensheet
35
Tocker Foundation Grant
32
National Museum of the Pacific War Oral History Collection
22
83 More
Degree Department
Degree Discipline
Degree Level
Country
States
Year
Month
Day
Results:
1 - 24 of
1,181
next
Coordination structure of adsorbed Zn(II) at Water-TiO2 interfaces
The local structure of aqueous metal ions on solid surfaces is central to understanding many chemical and biological processes in soil and aquatic environments. Here, the local coordination structure of hydrated Zn(II) at water-TiO{sub 2} interfaces was identified by extended X-ray absorption fine structure (EXAFS) and X-ray absorption near-edge structure (XANES) spectroscopy combined with density functional theory (DFT) calculations. A nonintegral coordination number of average {approx}4.5 O atoms around a central Zn atom was obtained by EXAFS analysis. DFT calculations indicated that this coordination structure was consistent with the mixture of 4-coordinated bidentate binuclear (BB) and 5-coordinated bidentate mononuclear (BM) metastable equilibrium adsorption (MEA) states. The BB complex has 4-coordinated Zn, while the monodentate mononuclear (MM) complex has 6-coordinated Zn, and a 5-coordinated adsorbed Zn was found in the BM adsorption mode. DFT calculated energies showed that the lower-coordinated BB and BM modes were thermodynamically more favorable than the higher-coordinated MM MEA state. The experimentally observed XANES fingerprinting provided additional direct spectral evidence of 4- and 5-coordinated Zn-O modes. The overall spectral and computational evidence indicated that Zn(II) can occur in 4-, 5-, and 6-oxygen coordinated sites in different MEA states due to steric hindrance effects, and the coexistence of …
Date:
January 15, 2011
Creator:
He, G.; Pan, G.; Zhang, M. & Waychunas, G.A.
Object Type:
Article
System:
The UNT Digital Library
Estimating the upper limit of gas production from Class 2 hydrate accumulations in the permafrost: 2. Alternative well designs and sensitivity analysis
In the second paper of this series, we evaluate two additional well designs for production from permafrost-associated (PA) hydrate deposits. Both designs are within the capabilities of conventional technology. We determine that large volumes of gas can be produced at high rates (several MMSCFD) for long times using either well design. The production approach involves initial fluid withdrawal from the water zone underneath the hydrate-bearing layer (HBL). The production process follows a cyclical pattern, with each cycle composed of two stages: a long stage (months to years) of increasing gas production and decreasing water production, and a short stage (days to weeks) that involves destruction of the secondary hydrate (mainly through warm water injection) that evolves during the first stage, and is followed by a reduction in the fluid withdrawal rate. A well configuration with completion throughout the HBL leads to high production rates, but also the creation of a secondary hydrate barrier around the well that needs to be destroyed regularly by water injection. However, a configuration that initially involves heating of the outer surface of the wellbore and later continuous injection of warm water at low rates (Case C) appears to deliver optimum performance over the period it …
Date:
January 15, 2011
Creator:
Moridis, G. & Reagan, M. T.
Object Type:
Article
System:
The UNT Digital Library
The Express-Star (Chickasha, Okla.), Ed. 1 Saturday, January 15, 2011
Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date:
January 15, 2011
Creator:
Wray, Kelly
Object Type:
Newspaper
System:
The Gateway to Oklahoma History
Factors governing sustainable groundwater pumping near a river
The objective of this paper is to provide new insights into processes affecting riverbank filtration (RBF). We consider a system with an inflatable dam installed for enhancing water production from downstream collector wells. Using a numerical model, we investigate the impact of groundwater pumping and dam operation on the hydrodynamics in the aquifer and water production. We focus our study on two processes that potentially limit water production of an RBF system: the development of an unsaturated zone and riverbed clogging. We quantify river clogging by calibrating a time-dependent riverbed permeability function based on knowledge of pumping rate, river stage, and temperature. The dynamics of the estimated riverbed permeability reflects clogging and scouring mechanisms. Our results indicate that (1) riverbed permeability is the dominant factor affecting infiltration needed for sustainable RBF production; (2) dam operation can influence pumping efficiency and prevent the development of an unsaturated zone beneath the riverbed only under conditions of sufficient riverbed permeability; (3) slow river velocity, caused by dam raising during summer months, may lead to sedimentation and deposition of fine-grained material within the riverbed, which may clog the riverbed, limiting recharge to the collector wells and contributing to the development of an unsaturated zone …
Date:
January 15, 2011
Creator:
Zhang, Y.; Hubbard, S. S. & Finsterle, S.
Object Type:
Article
System:
The UNT Digital Library
A high-pressure atomic force microscope for imaging in supercritical carbon dioxide
A high-pressure atomic force microscope (AFM) that enables in situ, atomic scale measurements of topography of solid surfaces in contact with supercritical CO{sub 2} (scCO{sub 2}) fluids has been developed. This apparatus overcomes the pressure limitations of the hydrothermal AFM and is designed to handle pressures up to 100 atm at temperatures up to ∼350 K. A standard optically-based cantilever deflection detection system was chosen. When imaging in compressible supercritical fluids such as scCO{sub 2} , precise control of pressure and temperature in the fluid cell is the primary technical challenge. Noise levels and imaging resolution depend on minimization of fluid density fluctuations that change the fluid refractive index and hence the laser path. We demonstrate with our apparatus in situ atomic scale imaging of a calcite (CaCO{sub 3}) mineral surface in scCO{sub 2}; both single, monatomic steps and dynamic processes occurring on the (10{overbar 1}4) surface are presented. This new AFM provides unprecedented in situ access to interfacial phenomena at solid–fluid interfaces under pressure.
Date:
January 15, 2011
Creator:
Lea, A. S.; Higgins, S. R.; Knauss, K. G. & Rosso, K. M.
Object Type:
Article
System:
The UNT Digital Library
Methane Hydrate Dissociation by Depressurization in a Mount Elbert Sandstone Sample: Experimental Observations and Numerical Simulations
A preserved sample of hydrate-bearing sandstone from the Mount Elbert Test Well was dissociated by depressurization while monitoring the internal temperature of the sample in two locations and the density changes at high spatial resolution using x-ray CT scanning. The sample contained two distinct regions having different porosity and grain size distributions. The hydrate dissociation occurred initially throughout the sample as a result of depressing the pressure below the stability pressure. This initial stage reduced the temperature to the equilibrium point, which was maintained above the ice point. After that, dissociation occurred from the outside in as a result of heat transfer from the controlled temperature bath surrounding the pressure vessel. Numerical modeling of the test using TOUGH+HYDRATE yielded a gas production curve that closely matches the experimentally measured curve.
Date:
January 15, 2011
Creator:
Kneafsey, T. & Moridis, G.J.
Object Type:
Article
System:
The UNT Digital Library
Perry Daily Journal (Perry, Okla.), Vol. 119, No. 10, Ed. 1 Saturday, January 15, 2011
Daily newspaper from Perry, Oklahoma that includes local, state, and national news along with advertising.
Date:
January 15, 2011
Creator:
Brown, Gloria
Object Type:
Newspaper
System:
The Gateway to Oklahoma History
Radiographic X-Ray Pulse Jitter
The Dual Beam Radiographic Facility consists of two identical radiographic sources. Major components of the machines are: Marx generator, water-filled pulse-forming line (PFL), water-filled coaxial transmission line, three-cell inductive voltage adder, and rod-pinch diode. The diode pulse has the following electrical specifications: 2.25-MV, 60-kA, 60-ns. Each source has the following x-ray parameters: 1-mm-diameter spot size, 4-rad at 1 m, 50-ns full width half max. The x-ray pulse is measured with PIN diode detectors. The sources were developed to produce high resolution images on single-shot, high-value experiments. For this application it is desirable to maintain a high level of reproducibility in source output. X-ray pulse jitter is a key metric for analysis of reproducibility. We will give measurements of x-ray jitter for each machine. It is expected that x-ray pulse jitter is predominantly due to PFL switch jitter, and therefore a correlation of the two will be discussed.
Date:
January 15, 2011
Creator:
Mitton, C. V., Good, D. E., Henderson, D. J., Hogge, K. W.
Object Type:
Article
System:
The UNT Digital Library
Summary of the Special Analysis of Savannah River Depleted Uranium Trioxide Demonstrating the Before and After Impacts on the DOE Order 435.1 Performance Objective and the Peak Dose
This report summarizes the special analysis (SA) of the Savannah River Depleted Uranium Trioxide waste stream (SVRSURANIUM03, Revision 1) demonstrating the before and after impacts of the waste stream to the DOE Order 435.1 performance objective at the disposal facility, and the peak dose. The Nevada Division of Environmental Protection (NDEP) requested this SA and asked the Nevada Site Office (NSO) to run the SA deterministically and assume that all the model conditions remain the same regardless of the length of time to the peak dose. Although the NDEP accepts that DOE Order 435.1 requires a compliance period of 1,000 years, it also requested to know what year, if any, the specific DOE performance objectives will be exceeded. Given the NDEP’s requested model conditions, the SA demonstrates the Rn-222 peak dose will occur in about 2 million years and will exceed the performance objective in about 6,000 years. The 0.25 mSv y-1 all-pathway performance objective was not exceeded for the resident scenario after reaching the 4 million year peak dose.
Date:
January 15, 2011
Creator:
Shott, G.J.
Object Type:
Report
System:
The UNT Digital Library
The Texas Compatriot, Winter 2010-2011
Publication of the Texas Society Sons of the American Revolution, containing news and events related to the organization and its members.
Date:
January 15, 2011
Creator:
Sons of the American Revolution. Texas Society.
Object Type:
Journal/Magazine/Newsletter
System:
The UNT Digital Library
Accountability for U.S. Equipment Provided to Pakistani Security Forces in the Western Frontier Needs to Be Improved
Correspondence issued by the Government Accountability Office with an abstract that begins "Al Qaeda, the Taliban, and other extremists have used safe havens along Pakistan's Western Frontier (border) region to attack Pakistani, Afghan, U.S., and coalition troops; plan and train for attacks against U.S. interests and the U.S. homeland; destabilize Pakistan, a nuclear-armed U.S. ally; and spread radical Islamic ideologies that threaten U.S. interests. A key U.S. national security objective is to disrupt, dismantle, and defeat al Qaeda and its violent extremist affiliates in Pakistan and to deny them a safe haven. Since 2002, the United States has provided over $18 billion in assistance and reimbursement to Pakistan including (1) reimbursements to the Pakistani government for costs incurred in direct support of U.S. counterterrorism operations; (2) security assistance such as grants to Pakistan for the acquisition of military equipment; and (3) development, economic, and humanitarian assistance. Since 2006, this assistance has included $1.5 billion to improve the counterterrorism and counterinsurgency capabilities of Pakistani security forces operating along the country's border with Afghanistan, including $400 million for the Pakistan Counterinsurgency Fund (PCF) and $700 million for the Pakistan Counterinsurgency Capabilities Fund (PCCF). The President has requested an additional $1.2 billion for …
Date:
February 15, 2011
Creator:
United States. Government Accountability Office.
Object Type:
Text
System:
The UNT Digital Library
The Altus Times (Altus, Okla.), Vol. 112, No. 311, Ed. 1 Tuesday, February 15, 2011
Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date:
February 15, 2011
Creator:
Bush, Michael
Object Type:
Newspaper
System:
The Gateway to Oklahoma History
The Baytown Sun (Baytown, Tex.), Vol. 90, No. 293, Ed. 1 Tuesday, February 15, 2011
Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date:
February 15, 2011
Creator:
Gray, Janie
Object Type:
Newspaper
System:
The Portal to Texas History
The Boerne Star (Boerne, Tex.), Vol. 105, No. 13, Ed. 1 Tuesday, February 15, 2011
Semiweekly newspaper from Boerne, Texas that includes local, state, and national news along with advertising.
Date:
February 15, 2011
Creator:
Cartwright, Brian & Velvin, Candace E.
Object Type:
Newspaper
System:
The Portal to Texas History
Border Security: Preliminary Observations on Border Control Measures for the Southwest Border
Testimony issued by the Government Accountability Office with an abstract that begins "The Department of Homeland Security (DHS) reports that the nearly 2,000-mile U.S. border with Mexico is vulnerable to cross-border illegal activity. The Office of Border Patrol (Border Patrol), within DHS's U.S. Customs and Border Protection (CBP), is responsible for securing the border between U.S. ports of entry and has divided responsibility for southwest border miles among nine Border Patrol sectors. CBP reported spending about $3 billion on Border Patrol's southwest border efforts in fiscal year 2010, apprehending over 445,000 illegal entries. This testimony provides preliminary observations on (1) the extent to which DHS reported progress in achieving operational control--Border Patrol was able to detect, respond, and interdict cross-border illegal activity--of the southwest border; (2) the extent to which operational control reflects Border Patrol's ability to respond to illegal activity at the border or after entry into the United States; and (3) how DHS reports the transition to new border security measures will change oversight and resource requirements for securing the southwest border. This testimony is based on GAO's ongoing work for the House Committee on Homeland Security. GAO analyzed DHS border security documents and data supporting border security …
Date:
February 15, 2011
Creator:
United States. Government Accountability Office.
Object Type:
Text
System:
The UNT Digital Library
The Brand (Abilene, Tex.), Vol. 99, No. 11, Ed. 1 Tuesday, February 15, 2011
Bi-weekly student newspaper from Hardin-Simmons University in Abilene, Texas that includes campus news and local news of interest to students along with advertising.
Date:
February 15, 2011
Creator:
Hahne, Elyse
Object Type:
Newspaper
System:
The Portal to Texas History
Captain John R. Hughes: Lone Star Ranger
Access:
Use of this item is restricted to the UNT Community
Captain John R. Hughes, Lone Star Ranger is the first full and complete modern biography of a man who served as a Texas Ranger from 1887 until early 1915. He came to the attention of the Rangers after doggedly trailing horse thieves for nearly a year and recovering his stolen stock. After helping Ranger Ira Aten track down another fugitive from justice, Hughes then joined Company D of the Texas Rangers on Aten’s recommendation, intending to stay for only a few months; he remained in the service for nearly thirty years. When Sgt. Charles Fusselman was killed by bandits, Hughes took his place. When Captain Frank Jones was killed by bandits in 1893, Hughes was named captain of Company D. As captain, Hughes and his men searched the border and identified every bandit involved in the killing of Jones. They all received justice. Toward the end of his career Hughes became a senior captain based in Austin, and in 1915, having served as a captain and ranger longer than any other man, he retired from the force. His later years were happy ones, with traveling and visiting friends and relatives. He became a Texas icon and national celebrity, receiving more …
Date:
February 15, 2011
Creator:
Parsons, Chuck
Object Type:
Book
System:
The UNT Digital Library
China's Energy and Carbon Emissions Outlook to 2050
As a result of soaring energy demand from a staggering pace of economic expansion and the related growth of energy-intensive industry, China overtook the United States to become the world's largest contributor to CO{sub 2} emissions in 2007. At the same time, China has taken serious actions to reduce its energy and carbon intensity by setting both a short-term energy intensity reduction goal for 2006 to 2010 as well as a long-term carbon intensity reduction goal for 2020. This study presents a China Energy Outlook through 2050 that assesses the role of energy efficiency policies in transitioning China to a lower emission trajectory and meeting its intensity reduction goals. Over the past few years, LBNL has established and significantly enhanced its China End-Use Energy Model which is based on the diffusion of end-use technologies and other physical drivers of energy demand. This model presents an important new approach for helping understand China's complex and dynamic drivers of energy consumption and implications of energy efficiency policies through scenario analysis. A baseline ('Continued Improvement Scenario') and an alternative energy efficiency scenario ('Accelerated Improvement Scenario') have been developed to assess the impact of actions already taken by the Chinese government as well as …
Date:
February 15, 2011
Creator:
Zhou, Nan; Fridley, David; McNeil, Michael; Zheng, Nina; Ke, Jing & Levine, Mark
Object Type:
Report
System:
The UNT Digital Library
Climate Change Issues: Options for Addressing Challenges to Carbon Offset Quality
A letter report issued by the Government Accountability Office with an abstract that begins "Carbon offsets are reductions in greenhouse gas emissions in one place to compensate for emissions elsewhere. Examples of offset projects include planting trees, developing renewable energy sources, or capturing emissions from landfills. Recent congressional proposals would have limited emissions from utilities, industries, or other "regulated entities," and allowed these entities to buy offsets. Research suggests that offsets can significantly lower the cost of a program to limit emissions because buying offsets may cost regulated entities less than making the reductions themselves. Some existing international and U.S. regional programs allow offsets to be used for compliance with emissions limits. A number of voluntary offset programs also exist, where buyers do not face legal requirements but may buy offsets for other reasons. Prior GAO work found that it can be difficult to ensure offset quality--that offsets achieve intended reductions. One quality criterion is that reductions must be "additional" to what would have occurred without the offset program. This report provides information on (1) key challenges in assessing the quality of different types of offsets and (2) options for addressing key challenges associated with offset quality if the U.S. …
Date:
February 15, 2011
Creator:
United States. Government Accountability Office.
Object Type:
Report
System:
The UNT Digital Library
Compensated Work Sharing Arrangements (Short-Time Compensation) as an Alternative to Layoffs
This report describes short-term compensation (STC) as a beneficial alternative to layoffs. It also describes the status of STC (or work sharing) in the U.S., particularly as it varies from state to state.
Date:
February 15, 2011
Creator:
Shelton, Alison M.
Object Type:
Report
System:
The UNT Digital Library
Constraining the reservoir model of an injected CO2 plume with crosswell CASSM at the Frio-II brine plot
Crosswell CASSM (continuous active-source seismic monitoring) data was acquired as part of the Frio-II brine pilot CO{sub 2} injection experiment. To gain insight into the CO{sub 2} plume evolution, we have integrated the 3D multiphase flow modeling code TOUGH2 with seismic simulation codes via a petrophysical model that predicts seismic velocity for a given CO{sub 2} saturation. Results of forward seismic modeling based on the CO{sub 2} saturation distribution produced by an initial TOUGH2 model compare poorly with the CASSM data, indicating that the initial flow model did not capture the actual CO{sub 2} plume dynamics. Updates to the TOUGH2 model required to better match the CASSM field data indicate vertical flow near the injection well, with increased horizontal plume growth occurring at the top of the reservoir sand. The CASSM continuous delay time data are ideal for constraining the modeled spatiotemporal evolution of the CO{sub 2} plume and allow improvement in reservoir model and estimation of CO{sub 2} plume properties.
Date:
February 15, 2011
Creator:
Daley, T. M.; Ajo-Franklin, J. & Doughty, C. A.
Object Type:
Article
System:
The UNT Digital Library
A data variance technique for automated despiking of magnetotelluric data with a remote reference
The magnetotelluric method employs co-located surface measurements of electric and magnetic fields to infer the local electrical structure of the earth. The frequency-dependent 'apparent resistivity' curves can be inaccurate at long periods if input data are contaminated - even when robust remote reference techniques are employed. Data despiking prior to processing can result in significantly more reliable estimates of long period apparent resistivities. This paper outlines a two-step method of automatic identification and replacement for spike-like contamination of magnetotelluric data; based on the simultaneity of natural electric and magnetic field variations at distant sites. This simultaneity is exploited both to identify windows in time when the array data are compromised, and to generate synthetic data that replace observed transient noise spikes. In the first step, windows in data time series containing spikes are identified via intersite comparison of channel 'activity' - such as the variance of differenced data within each window. In the second step, plausible data for replacement of flagged windows is calculated by Wiener filtering coincident data in clean channels. The Wiener filters - which express the time-domain relationship between various array channels - are computed using an uncontaminated segment of array training data. Examples are shown where …
Date:
February 15, 2011
Creator:
Kappler, K.
Object Type:
Article
System:
The UNT Digital Library
Doctoral Lecture Recital: 2011-02-15 – Katrin Meidell, viola
Recital presented at the UNT College of Music Recital Hall in partial fulfillment of the Doctor of Musical Arts (DMA) degree.
Date:
February 15, 2011
Creator:
Meidell, Katrin
Object Type:
Sound
System:
The UNT Digital Library
Economic Impacts of the Natural Gas Industry in North Texas
This presentation is part of the UNT Speaks Out faculty lecture series, Gas Well Drilling: What Does it Mean for North Texas? In this presentation, the author discusses the economic benefits to natural gas production, reviews the most recent study on regional economic impacts, considers recent trends in drilling activity, and considers some of the downsides.
Date:
February 15, 2011
Creator:
Clower, Terry L.
Object Type:
Presentation
System:
The UNT Digital Library