Compensatory Paracrine Mechanisms That Define The Urothelial Response to Injury in Partial Bladder Outlet Obstruction (open access)

Compensatory Paracrine Mechanisms That Define The Urothelial Response to Injury in Partial Bladder Outlet Obstruction

Diseases and conditions affecting the lower urinary tract are a leading cause of dysfunctional sexual health, incontinence, infection, and kidney failure. The growth, differentiation, and repair of the bladder's epithelial lining are regulated, in part, by fibroblast growth factor (FGF)-7 and -10 via a paracrine cascade originating in the mesenchyme (lamina propria) and targeting the receptor for FGF-7 and -10 within the transitional epithelium (urothelium). The FGF-7 gene is located at the 15q15-q21.1 locus on chromosome 15 and four exons generate a 3.852-kb mRNA. Five duplicated FGF-7 gene sequences that localized to chromosome 9 were predicted not to generate functional protein products, thus validating the use of FGF-7-null mice as an experimental model. Recombinant FGF-7 and -10 induced proliferation of human urothelial cells in vitro and transitional epithelium of wild-type and FGF-7-null mice in vivo.To determine the extent that induction of urothelial cell proliferation during the bladder response to injury is dependent on FGF-7, an animal model of partial bladder outlet obstruction was developed. Unbiased stereology was used to measure the percentage of proliferating urothelial cells between obstructed groups of wild-type and FGF-7-null mice. The stereological analysis indicated that a statistical significant difference did not exist between the two groups, …
Date: June 21, 2007
Creator: Bassuk, James; Lendvay, Thomas S.; Sweet, Robert; Han, Chang-Hee; Soygur, Tarkan; Cheng, Jan-Fang et al.
Object Type: Article
System: The UNT Digital Library
Toward a Deeper Understanding of Plutonium (open access)

Toward a Deeper Understanding of Plutonium

Plutonium is a very complex element lying near the middle of the actinide series. On the lower atomic number side of Pu is the element neptunium; its 5f electrons are highly delocalized or itinerant, participating in metallic-like bonding. The electrons in americium, the element to the right of Pu, are localized and do not participant significantly in the bonding. Plutonium is located directly on this rather abrupt transition. In the low-temperature {alpha} phase ground state, the five 5f electrons are mostly delocalized leading to a highly dense monoclinic crystal structure. Increases in temperature take the unalloyed plutonium through a series of five solid-state allotropic phase transformations before melting. One of the high temperature phases, the close-packed face centered cubic {delta} phase, is the least dense of all the phases, including the liquid. Alloying the Pu with Group IIIA elements such as aluminum or gallium retains the {delta} phase in a metastable state at ambient conditions. Ultimately, this metastable {delta} phase will decompose via a eutectoid transformation to {alpha} + Pu{sub 3}Ga. These low solute-containing {delta}-phase Pu alloys are also metastable with respect to low temperature excursions or increases in pressure and will transform to a monoclinic crystal structure at low …
Date: June 21, 2007
Creator: Schwartz, A J & Wolfer, W G
Object Type: Article
System: The UNT Digital Library
Unified Model of Dynamic Forced Barrier Crossing in Single Molecules (open access)

Unified Model of Dynamic Forced Barrier Crossing in Single Molecules

Thermally activated barrier crossing in the presence of an increasing load can reveal kinetic rate constants and energy barrier parameters when repeated over a range of loading rates. Here we derive a model of the mean escape force for all relevant loading rates--the complete force spectrum. Two well-known approximations emerge as limiting cases; one of which confirms predictions that single-barrier spectra should converge to a phenomenological description in the slow loading limit.
Date: June 21, 2007
Creator: Friddle, R W
Object Type: Article
System: The UNT Digital Library
On prediction of wind-borne plumes with simple models of turbulenttransport (open access)

On prediction of wind-borne plumes with simple models of turbulenttransport

The dispersion of pollutants from the ground by turbulent winds is difficult to model in general. However, for flat homogeneous terrain and steady wind conditions, if the wind profile is modeled with a power-law dependence on height, the advection-dispersion equation has an exact solution. In this paper the analytical solution is compared to a numerical simulation of the coupled air-ground system for a leaking underground gas storage, with a power-law velocity profile that was fit to the logarithmic velocity profile used in the simulation. The two methods produced similar results far from the boundaries, but the boundary conditions had a strong effect; the simulation imposed boundary conditions at the edge of a finite domain while the analytic solution imposes them at infinity. The reverse seepage from air to ground was shown in the simulation to be very small, and the sharp contrast between time scales suggests that air and ground can be modeled separately, with gas emissions from the ground model used as inputs to the air model.
Date: June 21, 2006
Creator: Schwarz, Katherine; Patzek, Tad & Silin, Dmitriy
Object Type: Article
System: The UNT Digital Library
Test of weak and strong factorization in nucleus-nucleuscollisions atseveral hundred MeV/nucleon (open access)

Test of weak and strong factorization in nucleus-nucleuscollisions atseveral hundred MeV/nucleon

Total and partial charge-changing cross sections have been measured for argon projectiles at 400 MeV/nucleon in carbon, aluminum, copper, tin and lead targets; cross sections for hydrogen were also obtained, using a polyethylene target. The validity of weak and strong factorization properties has been investigated for partial charge-changing cross sections; preliminary cross section values obtained for carbon, neon and silicon at 290 and 400 MeV/nucleon and iron at 400 MeV/nucleon, in carbon, aluminum, copper, tin and lead targets have been also used for testing these properties. Two different analysis methods were applied and both indicated that these properties are valid, without any significant difference between weak and strong factorization. The factorization parameters have then been calculated and analyzed in order to find some systematic behavior useful for modeling purposes.
Date: June 21, 2006
Creator: La Tessa, Chiara; Sihver, Lembit; Zeitlin, Cary; Miller, Jack; Guetersloh, Stephen; Heilbronn, Lawrence et al.
Object Type: Article
System: The UNT Digital Library
Nuclear Stewardship Research. (open access)

Nuclear Stewardship Research.

This report covers the period from June 2005 through May 2006. During this, the third year of our program, our research has focused mainly on applying the surrogate reaction technique and our newly developed surrogate ratio method to deduce neutron induced fission cross sections on uranium nuclei. The year has been marked by continued scientific progress, by the arrival of new personnel, by a growth in the numbers of students working in the group and by a continuation of our experimental program and close collaboration with staff and scientists from Lawrence Livermore National Laboratory and from Lawrence Berkeley National Laboratory.
Date: June 21, 2006
Creator: Beausang, C. W.
Object Type: Report
System: The UNT Digital Library
Coherent Beam Stability in the Low Momentum Compaction Lattice (open access)

Coherent Beam Stability in the Low Momentum Compaction Lattice

The beam dynamics for a quasi-isochronous lattice differs from that in the usual case of a lattice with a large positive momentum compaction factor. In particular, the quasi-isochronous lattice allows us to double the number of bunches which may be an attractive option for colliders. However, microwave instability and, as we show, longitudinal head-tail instability set the threshold for the beam current.
Date: June 21, 2006
Creator: Heifets, S. & Novokhatski, A.
Object Type: Article
System: The UNT Digital Library
Temporal Development of Ion Beam Mean Charge State in PulsedVacuum Arc Ion Sources (open access)

Temporal Development of Ion Beam Mean Charge State in PulsedVacuum Arc Ion Sources

Vacuum arc ion sources, commonly also known as "Mevva" ionsources, are used to generate intense pulsed metal ion beams. It is knownthat the mean charge state of the ion beam lies between 1 and 4,depending on cathode material, arc current, arc pulse duration, presenceor absence of magnetic field at the cathode, as well background gaspressure. A characteristic of the vacuum arc ion beam is a significantdecrease in ion charge state throughout the pulse. This decrease can beobserved up to a few milliseconds, until a "noisy" steady-state value isestablished. Since the extraction voltage is constant, a decrease in theion charge state has a proportional impact on the average ion beamenergy. This paper presents results of detailed investigations of theinfluence of arc parameters on the temporal development of the ion beammean charge state for a wide range of cathode materials. It is shown thatfor fixed pulse duration, the charge state decrease can be reduced bylower arc current, higher pulse repetition rate, and reduction of thedistance between cathode and extraction region. The latter effect may beassociated with charge exchange processes in the dischargeplasma.
Date: June 21, 2007
Creator: Oks, Efim M.; Yushkov, Georgy Yu. & Anders, Andre
Object Type: Article
System: The UNT Digital Library
High Gradient Induction Accelerator (open access)

High Gradient Induction Accelerator

A new type of compact induction accelerator is under development at the Lawrence Livermore National Laboratory that promises to increase the average accelerating gradient by at least an order of magnitude over that of existing induction machines. The machine is based on the use of high gradient vacuum insulators, advanced dielectric materials and switches and is stimulated by the desire for compact flash x-ray radiography sources. Research describing an extreme variant of this technology aimed at proton therapy for cancer will be described. Progress in applying this technology to several applications will be reviewed.
Date: June 21, 2007
Creator: Caporaso, G. J.; Sampayan, S.; Chen, Y.; Blackfield, D.; Harris, J.; Hawkins, S. et al.
Object Type: Article
System: The UNT Digital Library
A Novel Approach to Mineral Carbonation: Enhancing Carbonation While Avoiding Mineral Pretreatment Process Cost (open access)

A Novel Approach to Mineral Carbonation: Enhancing Carbonation While Avoiding Mineral Pretreatment Process Cost

Known fossil fuel reserves, especially coal, can support global energy demands for centuries to come, if the environmental problems associated with CO{sub 2} emissions can be overcome. Unlike other CO{sub 2} sequestration candidate technologies that propose long-term storage, mineral sequestration provides permanent disposal by forming geologically stable mineral carbonates. Carbonation of the widely occurring mineral olivine (e.g., forsterite, Mg{sub 2}SiO{sub 4}) is a large-scale sequestration process candidate for regional implementation, which converts CO{sub 2} into the environmentally benign mineral magnesite (MgCO{sub 3}). The primary goal is cost-competitive process development. As the process is exothermic, it inherently offers low-cost potential. Enhancing carbonation reactivity is key to economic viability. Recent studies at the U.S. DOE Albany Research Center have established that aqueous-solution carbonation using supercritical CO{sub 2} is a promising process; even without olivine activation, 30-50% carbonation has been achieved in an hour. Mechanical activation (e.g., attrition) has accelerated the carbonation process to an industrial timescale (i.e., near completion in less than an hour), at reduced pressure and temperature. However, the activation cost is too high to be economical and lower cost pretreatment options are needed. We have discovered that robust silica-rich passivating layers form on the olivine surface during carbonation. As …
Date: June 21, 2007
Creator: Chizmeshya, Andrew V. G.; McKelvy, Michael J.; Squires, Kyle; Carpenter, Ray W. & Bearat, Hamdallah
Object Type: Report
System: The UNT Digital Library
Effective Error Bounds in Euler-Maclaurin-Based QuadratureSchemes (open access)

Effective Error Bounds in Euler-Maclaurin-Based QuadratureSchemes

We analyze the behavior of Euler-Maclaurin-basedintegrationschemes with the intention of deriving accurate andeconomicestimations of the error term.
Date: June 21, 2005
Creator: Bailey, David H. & Borwein, Jonathan M.
Object Type: Report
System: The UNT Digital Library
A "Snowflake" Divertor and its Properties (open access)

A "Snowflake" Divertor and its Properties

Handling the power and particle exhaust in fusion reactors based on tokamaks is a challenging problem [1,2]. To bring the energy flux to the divertor plates to an acceptable level (< 10 MW/m2), it is desirable to significantly increase poloidal flux expansion in the divertor area. Some recent ideas include that of a so-called X divertor [3] and a 'snowflake' divertor [4]. We use an acronym SF to designate the latter. In this paper we concentrate on the SF divertor. The general idea behind this configuration is that, by a proper selection of divertor (poloidal field) coils, one can make the null point of the second, not of the first order as in the standard divertor. The separatrix in the vicinity of the X point then acquires a characteristic hexapole structure (Fig. 1), reminiscent of a snowflake, whence the name. The fact that the field has a second-order null, leads to a significant increase of the flux expansion. It was noted in Ref. [4] that the SF configuration is topologically unstable: if the current in the divertor coils is somewhat higher than the one that provides the SF configuration, it becomes a single-null X-point configuration. Conversely, if the coil current …
Date: June 21, 2007
Creator: Ryutov, D.
Object Type: Article
System: The UNT Digital Library
Immiscibility in the Nickel Ferrite-Zinc Ferrite Spinel Binary (open access)

Immiscibility in the Nickel Ferrite-Zinc Ferrite Spinel Binary

Immiscibility in the trevorite (NiFe{sub 2}O{sub 4}) - franklinite (ZnFe{sub 2}O{sub 4}) spinel binary is investigated by reacting 1:1:2 molar ratio mixtures of NiO, ZnO and Fe{sub 2}O{sub 3} in a molten salt solvent at temperatures in the range 400-1000 C. Single phase stability is demonstrated down to about 730 C (the estimated consolute solution temperature, T{sub cs}). A miscibility gap/solvus exists below Tcs. The solvus becomes increasingly asymmetric at lower temperatures and extrapolates to n - values = 0.15, 0.8 at 300 C. A thermodynamic analysis, which accounts for changes in configurational and magnetic ordering entropies during cation mixing, predicts solvus phase compositions at room temperature in reasonable agreement with those determined by extrapolation of experimental results. The delay between disappearance of magnetic ordering above T{sub C} = 590 C (for NiFe{sub 2}O{sub 4}) and disappearance of a miscibility gap at T{sub cs} is explained by the persistence of long-range ordering correlations in a quasi-paramagnetic region above T{sub C}.
Date: June 21, 2006
Creator: Ziemniak, SE; Gaddipati, AR; Sander, PC & Rice, SB
Object Type: Article
System: The UNT Digital Library
The Influence of the In-Situ Clad Staining on the Corrosion of Zircaloy in PWR Water Environment (open access)

The Influence of the In-Situ Clad Staining on the Corrosion of Zircaloy in PWR Water Environment

Zircaloy cladding tubes strain in-situ during service life in the corrosive environment of a Pressurized Water Reactor for a variety of reasons. First, the tube undergoes stress free growth due to the preferential alignment of irradiation induced vacancy loops on basal planes. Positive strains develop in the textured tubes along prism orientations while negative strains develop along basal orientations (Reference (a)). Second, early in life, free standing tubes will often shrink by creep in the diametrical direction under the external pressure of the water environment, but potentially grow later in life in the diametrical direction once the expanding fuel pellet contacts the cladding inner wall (Reference (b)). Finally, the Zircaloy cladding absorbs hydrogen as a by product of the corrosion reaction (Reference (c)). Once above the solubility limit in Zircaloy, the hydride precipitates as zirconium hydride (References (c) through (j)). Both hydrogen in solid solution and precipitated as Zirconium hydride cause a volume expansion of the Zircaloy metal (Reference (k)). Few studies are reported on that have investigated the influence that in-situ clad straining has on corrosion of Zircaloy. If Zircaloy corrosion rates are governed by diffusion of anions through a thin passivating boundary layer at the oxide-to-metal interface (References …
Date: June 21, 2001
Creator: Kammenzind, B.F., Eklund, K.L. and Bajaj, R.
Object Type: Report
System: The UNT Digital Library
Final Report West Valley High-Level Waste Tank Lay-Up (open access)

Final Report West Valley High-Level Waste Tank Lay-Up

This report documents completion of Milestone A.4-1 "Issue Tank Lay-Up Strategies for WVDP Final Report," in Technical Task Plan RL3-WT21A, "Post-Retrieval and Pre-Closure HLW Tank Lay-Up." This task was a collaborative effort among Pacific Northwest National Laboratory, Jacobs Engineering Group Inc., and West Valley Nuclear Services. The primary objective of the overall task was to develop and evaluate conceptual strategies for preclosure lay-up of the two large high-level waste storage tanks at the West Valley Demonstration Project.
Date: June 21, 2002
Creator: Elmore, Monte R. & Henderson, Colin
Object Type: Report
System: The UNT Digital Library
Compensation for Bunch Emittance in a Magnetization and Space Charge Dominated Beam. (open access)

Compensation for Bunch Emittance in a Magnetization and Space Charge Dominated Beam.

In order to obtain sufficient cooling rates for the Relativistic Heavy Ion Collider (RHIC) electron cooling, a bunched beam with high bunch charge, high repetition frequency and high energy is required and it is necessary to use a ''magnetized'' beam, i.e., an electron beam with non-negligible angular momentum. Applying a longitudinal solenoid field on the cathode can generate such a beam, which rotates around its longitudinal axis in a field-free region. This paper suggests how a magnetized beam can be accelerated and transported from a RF photocathode electron gun to the cooling section without significantly increasing its emittance. The evolution of longitudinal slices of the beam under a combination of space charge and magnetization is investigated, using paraxial envelope equations and numerical simulations. We find that we must modify the traditional method of compensating for emittance as used for normal non-magnetized beam with space charge to account for magnetization. The results of computer simulations of successful compensation are presented. Alternately, we show an electron bunch density distribution for which all slices propagate uniformly and which does not require emittance compensation.
Date: June 21, 2004
Creator: Chang, X.; Ben-Zvi, Ilan & Kewisch, J.
Object Type: Article
System: The UNT Digital Library
Hillslope Flow Routing, Contaminant Transport, and Water Uptake in Zero-Order Watersheds Subject to Intensive Forest Plantation Management. Phase 1A: Watershed and Soil Characterization. Phase 1B: Instrumentation of First Hillslope and Trench (open access)

Hillslope Flow Routing, Contaminant Transport, and Water Uptake in Zero-Order Watersheds Subject to Intensive Forest Plantation Management. Phase 1A: Watershed and Soil Characterization. Phase 1B: Instrumentation of First Hillslope and Trench

Abstract – An accomplishment report from a hill slope hydrology study in South Carolina.
Date: June 21, 2009
Creator: Jackson, Rhett, C.
Object Type: Report
System: The UNT Digital Library
Low-Frequency Electromagnetic Backscatter from Buried Tunnels (open access)

Low-Frequency Electromagnetic Backscatter from Buried Tunnels

This progress report is submitted under a contract between the Special Project Office of DARPA and Lawrence Livermore National Laboratory. The Project Manager at DARPA is Dr. Michael Zatman. Our purpose under this contract is to investigate interactions between electromagnetic waves and a class of buried targets located in multilayered media with rough interfaces. In this report, we investigate three preliminary problems. In each case our specific goal is to understand various aspects of the electromagnetic wave interaction mechanisms with targets in layered media. The first problem, discussed in Section 2, is that of low-frequency electromagnetic backscattering from a tunnel that is cut into a lossy dielectric half-space. In this problem, the interface between the upper (free space) region and the lower (ground) region is smooth. The tunnel is assumed to be a cylindrical free-space region of infinite extent in its axial direction and with a diameter that is small in comparison to the free-space wavelength. Because its diameter is small, the tunnel can be modeled as a buried ''wire'' described by an equivalent impedance per unit length. In Section 3 we extend the analysis to include a statistically rough interface between the air and ground regions. The interface is …
Date: June 21, 2006
Creator: Casey, K & Pao, H
Object Type: Report
System: The UNT Digital Library
Inhibitive Effect of Fluoride on the Crevice Corrosion of Alloy C-22 Induced by Chloride (Efecto Inhibidor del Fluoruro sobre la Corrosi?n en Rendijas de la Aleaci?n C-22 Inducida por Cloruros) (open access)

Inhibitive Effect of Fluoride on the Crevice Corrosion of Alloy C-22 Induced by Chloride (Efecto Inhibidor del Fluoruro sobre la Corrosi?n en Rendijas de la Aleaci?n C-22 Inducida por Cloruros)

None
Date: June 21, 2005
Creator: Carranza, R M; Rodr?guez, M A & Rebak, R B
Object Type: Article
System: The UNT Digital Library
Space Charge and Equilibrium Emittances in Damping Rings (open access)

Space Charge and Equilibrium Emittances in Damping Rings

We present a model of dynamics to account for the possible impact of space charge on the equilibrium emittances in storage rings and apply the model to study the current design of the International Linear Collider (ILC) damping rings.
Date: June 21, 2006
Creator: Venturini, Marco; Oide, Katsunobu & Wolski, Andy
Object Type: Article
System: The UNT Digital Library
Performance of a Nanometer Resolution Bpm System (open access)

Performance of a Nanometer Resolution Bpm System

International Linear Collider (ILC) interaction region beam sizes and component position stability requirements will be as small as a few nanometers. It is important to the ILC design effort to demonstrate that these tolerances can be achieved--ideally using beam-based stability measurements. It has been estimated that RF cavity beam position monitors (BPMs) could provide position measurement resolutions of less than one nanometer and could form the basis of the desired beam-based stability measurement. We have developed a high resolution RF cavity BPM system. A triplet of these BPMs has been installed in the extraction line of the KEK Accelerator Test Facility (ATF) for testing with its ultra-low emittance beam. The three BPMs are rigidly mounted inside an alignment frame on variable-length struts which allow movement in position and angle. We have developed novel methods for extracting the position and tilt information from the BPM signals including a calibration algorithm which is immune to beam jitter. To date, we have been able to demonstrate a resolution of approximately 20 nm over a dynamic range of +/- 20 microns. We report on the progress of these ongoing tests.
Date: June 21, 2006
Creator: Walston, S.; Chung, C.; Fitsos, P.; Gronberg, J.; Meller, R.; Vogel, V. et al.
Object Type: Article
System: The UNT Digital Library
Biotechnology for the Environment (open access)

Biotechnology for the Environment

Joint US-European Community Pilot Program support for short-term exchanges of early career scientists.
Date: June 21, 2005
Creator: Suflita, Joseph M. & Wall, Judy D.
Object Type: Report
System: The UNT Digital Library
Absolute Measurement of Electron Cloud Density (open access)

Absolute Measurement of Electron Cloud Density

Beam interaction with background gas and walls produces ubiquitous clouds of stray electrons that frequently limit the performance of particle accelerator and storage rings. Counterintuitively we obtained the electron cloud accumulation by measuring the expelled ions that are originated from the beam-background gas interaction, rather than by measuring electrons that reach the walls. The kinetic ion energy measured with a retarding field analyzer (RFA) maps the depressed beam space-charge potential and provides the dynamic electron cloud density. Clearing electrode current measurements give the static electron cloud background that complements and corroborates with the RFA measurements, providing an absolute measurement of electron cloud density during a 5 {micro}s duration beam pulse in a drift region of the magnetic transport section of the High-Current Experiment (HCX) at LBNL.
Date: June 21, 2007
Creator: Covo, M K; Molvik, A W; Cohen, R H; Friedman, A; Seidl, P A; Logan, G et al.
Object Type: Article
System: The UNT Digital Library
Carbon sequestration by patch fertilization: A comprehensive assessment using coupled physical-ecological-biogeochemical models: FINAL REPORT of grant Grant No. DE-FG02-04ER63726 (open access)

Carbon sequestration by patch fertilization: A comprehensive assessment using coupled physical-ecological-biogeochemical models: FINAL REPORT of grant Grant No. DE-FG02-04ER63726

This final report summarizes research undertaken collaboratively between Princeton University, the NOAA Geophysical Fluid Dynamics Laboratory on the Princeton University campus, the State University of New York at Stony Brook, and the University of California, Los Angeles between September 1, 2000, and November 30, 2006, to do fundamental research on ocean iron fertilization as a means to enhance the net oceanic uptake of CO2 from the atmosphere. The approach we proposed was to develop and apply a suite of coupled physical-ecologicalbiogeochemical models in order to (i) determine to what extent enhanced carbon fixation from iron fertilization will lead to an increase in the oceanic uptake of atmospheric CO2 and how long this carbon will remain sequestered (efficiency), and (ii) examine the changes in ocean ecology and natural biogeochemical cycles resulting from iron fertilization (consequences). The award was funded in two separate three-year installments: • September 1, 2000 to November 30, 2003, for a project entitled “Ocean carbon sequestration by fertilization: An integrated biogeochemical assessment.” A final report was submitted for this at the end of 2003 and is included here as Appendix 1. • December 1, 2003 to November 30, 2006, for a follow-on project under the same grant number …
Date: June 21, 2007
Creator: Sarmiento, Jorge L; Gnanadesikan, Anand & Gruber, Nicolas
Object Type: Report
System: The UNT Digital Library