120-Channel, Chronically Implantable, Wireless, Polymer Neural Interface (open access)

120-Channel, Chronically Implantable, Wireless, Polymer Neural Interface

None
Date: May 9, 2012
Creator: Tooker, A; Shah, K; Tolosa, V; Sheth, H; Felix, S; Delima, T et al.
System: The UNT Digital Library
Accurate Iterative Analysis of the K-V Equations (open access)

Accurate Iterative Analysis of the K-V Equations

Those working with alternating-gradient (A-G) systems look for simple, accurate ways to analyze A-G performance for matched beams. The useful K-V equations are easily solved in the smooth approximation. This approximate solution becomes quite inaccurate for applications with large focusing fields and phase advances. Results of efforts to improve the accuracy have tended to be indirect or complex. Their generalizations presented previously gave better accuracy in a simple explicit format. However, the method used to derive their results (expansion in powers of a small parameter) was complex and hard to follow; also, reference 7 only gave low-order correction formulas. The present paper uses a straightforward iteration method and obtains equations of higher order than shown in their previous paper.
Date: May 9, 2005
Creator: Anderson, O. A.
System: The UNT Digital Library
The advantages of including professionals from different fields of study in the solution of today`s water-related problems (open access)

The advantages of including professionals from different fields of study in the solution of today`s water-related problems

This report presents the details of a meeting of the American Society of Civil Engineers pertaining to water resources and quality. This report suggests an interdisciplinary approach to solving today`s problems dealing with water resources.
Date: May 9, 1995
Creator: Renshaw, A.
System: The UNT Digital Library
AEM Analysis of SCC in Alloy 690 Tested in 10% Caustic and 10% Caustic + PbO (open access)

AEM Analysis of SCC in Alloy 690 Tested in 10% Caustic and 10% Caustic + PbO

This report talks about AEM Analysis of SCC in Alloy 690 Tested in 10% Caustic and 10% Caustic + PbO.
Date: May 9, 2005
Creator: Lewis, N.; Shei, S.; Pica, P.; Bussert, B. & Hermer, R.
System: The UNT Digital Library
Agile manufacturing prototyping system (AMPS) (open access)

Agile manufacturing prototyping system (AMPS)

The Agile Manufacturing Prototyping System (AMPS) is being integrated at Sandia National Laboratories. AMPS consists of state of the industry flexible manufacturing hardware and software enhanced with Sandia advancements in sensor and model based control; automated programming, assembly and task planning; flexible fixturing; and automated reconfiguration technology. AMPS is focused on the agile production of complex electromechanical parts. It currently includes 7 robots (4 Adept One, 2 Adept 505, 1 Staubli RX90), conveyance equipment, and a collection of process equipment to form a flexible production line capable of assembling a wide range of electromechanical products. This system became operational in September 1995. Additional smart manufacturing processes will be integrated in the future. An automated spray cleaning workcell capable of handling alcohol and similar solvents was added in 1996 as well as parts cleaning and encapsulation equipment, automated deburring, and automated vision inspection stations. Plans for 1997 and out years include adding manufacturing processes for the rapid prototyping of electronic components such as soldering, paste dispensing and pick-and-place hardware.
Date: May 9, 1998
Creator: Garcia, P.
System: The UNT Digital Library
Airbreathing Acceleration Toward Earth Orbit (open access)

Airbreathing Acceleration Toward Earth Orbit

As flight speed increases, aerodynamic drag rises more sharply than the availability of atmospheric oxygen. The ratio of oxygen mass flux to dynamic pressure cannot be improved by changing altitude. The maximum possible speed for airbreathing propulsion is limited by the ratio of air capture area to vehicle drag area, approximately Mach 6 at equal areas. Simulation of vehicle acceleration shows that the use of atmospheric oxygen offers a significant potential for minimizing onboard consumables at low speeds. These fundamental calculations indicate that a practical airbreathing launch vehicle would accelerate to near steady-state speed while consuming only onboard fuel, then transition to rocket propulsion. It is suggested that an aircraft carrying a rocket-propelled vehicle to approximately Mach 5 could be a realistic technical goal toward improving access to orbit.
Date: May 9, 2007
Creator: Whitehead, J C
System: The UNT Digital Library
Analytical methods of electrode design for a relativistic electron gun (open access)

Analytical methods of electrode design for a relativistic electron gun

The standard paraxial ray equation method for the design of electrodes for an electrostatically focused gun is extended to include relativistic effects and the effects of the beam's azimuthal magnetic field. Solutions for parallel and converging beams are obtained and the predicted currents are compared against those measured on the High Brightness Test Stand. 4 refs., 2 figs.
Date: May 9, 1985
Creator: Caporaso, G.J.; Cole, A.G. & Boyd, J.K.
System: The UNT Digital Library
Application of high resolution crosswell radar and seismic for mapping flow in the vadose zone (open access)

Application of high resolution crosswell radar and seismic for mapping flow in the vadose zone

Geophysical imaging in the vadose zone poses unique issues. Groundwater contamination at DOE's Hanford, Washington site needs optimal imaging because extremely high drilling costs make direct characterization quite expensive. We conducted seismic and radar crosswell experiments to help answer basic questions about high resolution geophysical characterization. We acquired time lapse surveys during controlled injections of river water and saline solution. Radar imaging of dielectric changes delineated geological layers and moisture movement with 0.25 m resolution. Seismic velocity measurements delineated lithology at 0.25 m resolution with sensitivity to porosity and density changes in sediments and penetration of over 20 m using two sources of different bandwidths.
Date: May 9, 2002
Creator: Majer, Ernest L.; Williams, Kenneth H.; Peterson, John E. & Daley, Thomas M.
System: The UNT Digital Library
Application of muon spin relaxation experiment to the mixed state superconductors (open access)

Application of muon spin relaxation experiment to the mixed state superconductors

We discuss the use of muon spin relaxation ({mu}{sup +}SR) technique to study the mixed state of superconductors. Besides the application for static vortex configurations, we argue that large vortex motion can manifest itself as a narrowed time-averaged field distribution, which in turn results in a smaller relaxation rate. A static but disordered vortex configuration can also reduce the relaxation. We summarize these arguments. 7 refs.
Date: May 9, 1991
Creator: Inui, M. (Los Alamos National Lab., NM (USA)) & Harshman, D.R. (AT and T Bell Labs., Murray Hill, NJ (USA))
System: The UNT Digital Library
Auger Spectroscopy Results from Ductility Dip Cracks Opened Under Ultra-High Vacuum (open access)

Auger Spectroscopy Results from Ductility Dip Cracks Opened Under Ultra-High Vacuum

This report talks about Auger Spectroscopy Results from Ductility Dip Cracks Opened Under Ultra-High Vacuum.
Date: May 9, 2005
Creator: Capobianco, T. & Hanson, M.
System: The UNT Digital Library
The Average Star Formation Histories of Galaxies in Dark Matter Halos from z = 0-8 (open access)

The Average Star Formation Histories of Galaxies in Dark Matter Halos from z = 0-8

Presents a method to constrain average galaxy star formation rates, star formation histories, and the intracluster light as a function of halo mass.
Date: May 9, 2013
Creator: Behroozi, Peter S.; Wechsler, Risa H. & Conroy, Charlie
System: The UNT Digital Library
Band gap bowing and electron localization of (GaxIn1-x)N (open access)

Band gap bowing and electron localization of (GaxIn1-x)N

The band gap bowing and the electron localization ofGaxIn1-xN are calculated using both the local density approximation (LDA)and screened-exchange local density functional (sX-LDA) methods. Thecalculated sX-LDA band gaps are in good agreement with the experimentallyobserved values, with errors of -0.26 and 0.09 eV for bulk GaN and InN,respectively. The LDA band gap errors are 1.33 and 0.81 eV for GaN andInN, in order. In contrast to the gap itself, the band gap bowingparameter is found to be very similar in sX-LDA and LDA. We identify thelocalization of hole states in GaxIn1-xN alloys along In-N-In chains. Thepredicted localizationis stronger in sX-LDA.
Date: May 9, 2006
Creator: Lee, Byounghak & Wang, Lin-Wang
System: The UNT Digital Library
Beam-Based Alignment And Beta Function Measurements in PEP-II (open access)

Beam-Based Alignment And Beta Function Measurements in PEP-II

Careful optics studies and stringent lattice control have been identified as two key components to increasing PEP-II luminosity. An accurate, trusted BPM system is required for both of these strategies. To validate the existing BPM system and to better understand some optical anomalies in the PEP-II rings, an aggressive program of beam-based alignment (BBA) has been initiated. Using a quad-shunt BBA procedure in which a quadrupole's field strength is varied over a range of beam positions, relative offsets are determined by the BPM readings at which quadrupole field changes no longer induce a closed orbit shift. This procedure was verified in the HER and is well underway in the LER IR. We have found several surprisingly large BPM offsets, one over one centimeter, as well as a number of locations where the current nominal orbit is several millimeters from the design. Tune versus quadrupole field data were taken during the BBA process in the LER IR, and the non-linear response in each case is compared to simulation to infer local beta functions.
Date: May 9, 2005
Creator: Nelson, J.; Ross, M. C.; Smith, T. J.; Turner, J. L.; Woodley, M. & Yocky, G.
System: The UNT Digital Library
Beam expansion with specified final distributions (open access)

Beam expansion with specified final distributions

The formation of nearly uniformly distributed beams has been accomplished by the use of multipole magnets. Multipole fields, however, are an inappropriate basis for creating precise distributions, particularly since substantial departures from uniformity are produced with a finite number of multipole elements. A more appropriate formalism that allows precise formation of a desired distribution is presented. Design of nonlinear magnets for uniform-beam production and the optics of an accompanying expansion system are presented.
Date: May 9, 1997
Creator: Jason, A.J.; Blind, B. & Halbach, K.
System: The UNT Digital Library
Beam Measurements at LCLS (open access)

Beam Measurements at LCLS

None
Date: May 9, 2012
Creator: Frisch, J.; Akre, R.; Decker, F. J.; Ding, Y.; Dowell, D.; Emma, P. et al.
System: The UNT Digital Library
Beam Transport in a Compact Dielectric Wall Induction Accelerator System for Pulsed Radiography (open access)

Beam Transport in a Compact Dielectric Wall Induction Accelerator System for Pulsed Radiography

Using dielectric wall accelerator technology, we are developing a compact induction accelerator system primarily intended for pulsed radiography. The accelerator would provide a 2-kA beam with an energy of 8 MeV, for a 20-30 ns flat-top. The design goal is to generate a 2-mm diameter, 10-rad x-ray source. We have a physics design of the system from injector to the x-ray converter. We present the results of injector modeling and PIC simulations of beam transport. We also discuss the predicted spot size and the on-axis x-ray dose.
Date: May 9, 2005
Creator: McCarrick, J. F.; Caporaso, G. J. & Chen, Y.
System: The UNT Digital Library
Benchmark Calculation of Inclusive Electromagnetic Responses in the Four-Body Nuclear System (open access)

Benchmark Calculation of Inclusive Electromagnetic Responses in the Four-Body Nuclear System

Both the no-core shell model and the effective interaction hyperspherical harmonic approaches are applied to the calculation of different response functions to external electromagnetic probes, using the Lorentz integral transform method. The test is performed on the four-body nuclear system, within a simple potential model. The quality of the agreement in the various cases is discussed, together with the perspectives for rigorous ab initio calculations of cross sections of heavier nuclei.
Date: May 9, 2006
Creator: Stetcu, I.; Quaglioni, S.; Bacca, S.; Barrett, B. R.; Johnson, C. W.; Navratil, P. et al.
System: The UNT Digital Library
Benchmark Studies of the Effectiveness of Structural and Internal Materials as Radiation Shielding for the International Space Station (open access)

Benchmark Studies of the Effectiveness of Structural and Internal Materials as Radiation Shielding for the International Space Station

Accelerator-based measurements and model calculations have been used to study the heavy ion radiation transport properties of materials in use on the International Space Station (ISS). Samples of the ISS aluminum outer hull were augmented with various configurations of internal wall material and polyethylene. The materials were bombarded with high energy Fe ions characteristic of a significant part of the Galactic Cosmic Ray (GCR) heavy ion spectrum. Transmitted primary ions and charged fragments produced in nuclear collisions in the materials were measured near the beam axis, and a model was used to extrapolate from the data to lower beam energies and to a lighter ion. For the materials and ions studied, at incident particle energies from 1037 MeV/nucleon down to at least 600 MeV/nucleon, nuclear fragmentation reduces the average dose and dose equivalent per incident ion. At energies below 400 MeV/nucleon, the calculation predicts that as material is added, increased ionization energy loss produces increases in some dosimetric quantities. These limited results suggest that the addition of modest amounts of polyethylene or similar material to the interior of the ISS will reduce the dose to ISS crews from space radiation; however the radiation transport properties of ISS materials should be …
Date: May 9, 2002
Creator: Miller, J.; Zeitlin, C.; Cucinotta, F. A.; Heilbronn, L.; Stephens, D. & Wilson, J. W.
System: The UNT Digital Library
Bridged polysilsesquioxanes: A molecular based approach for the synthesis of functional hybrid materials (open access)

Bridged polysilsesquioxanes: A molecular based approach for the synthesis of functional hybrid materials

Bridged polysilsesquioxanes (BPS) are a family of hybrid organic-inorganic materials prepared by sol-gel polymerization of molecular building blocks that contain a variable organic component and at least two trifunctional silyl groups. The resulting xerogels and aerogels have physical and mechanical properties that are strongly influenced by the organic bridging group. This talk focuses on the synthesis of functional bridged polysilsesquioxanes. Incorporation of functional groups that respond to chemical, photochemical, or thermal stimuli can provide handles for modifying bulk morphology and/or provide function. These materials can find use as ion exchange media, chromatographic stationary phases, photoresists and high capacity selective chemical absorbents.
Date: May 9, 2000
Creator: SHEA,KENNETH J. & LOY,DOUGLAS A.
System: The UNT Digital Library
Brightness and Coherence of Synchrotron Radiation and FELs (open access)

Brightness and Coherence of Synchrotron Radiation and FELs

None
Date: May 9, 2013
Creator: Huang, Zhirong
System: The UNT Digital Library
Brightness measurements on the Livermore high brightness test stand (open access)

Brightness measurements on the Livermore high brightness test stand

Several techniques using small radius collimating pipes with and without axial magnetic fields to measure the brightness of an extracted 1 - 2 kA, 1 - 1.5 MeV electron beam will be described. The output beam of the High Brightness Test Stand as measured by one of these techniques is in excess of 2 x 10/sup 5/ amp/cm/sup 2//steradian. 5 refs., 4 figs.
Date: May 9, 1985
Creator: Caporaso, G.J. & Birx, D.L.
System: The UNT Digital Library
Bunch Pattern With More Bunches in PEP-II (open access)

Bunch Pattern With More Bunches in PEP-II

The number of bunches in the PEP-II B-Factory has increased over the years. The luminosity has followed roughly linearly that increase or even faster since we have also lowered the spot size at the interaction point. The recent steps from 939 bunches in June of 2003 to about 1320 in February 2004 (and 1585 in May) should have been followed by a similar rise in luminosity from 6.5 {center_dot} 10{sup 33} l/cm{sup 2} {center_dot} 1/s to 9.1 {center_dot} 10{sup 33} 1/cm{sup 2} {center_dot} 1/s (or even 11 {center_dot} 10{sup 33} 1/cm{sup 2} {center_dot} 1/s in May). This didn't happen so far and a peak luminosity of ''only'' 7.3 {center_dot} 10{sup 33} 1/cm{sup 2} {center_dot} 1/s (or 9.2 {center_dot} 10{sup 33} 1/cm{sup 2} {center_dot} 1/s in May) was achieved with less bunch currents. By filling the then partially filled by-3 pattern to a completely filled by-3 pattern (1133 bunches) we should get 7.9 {center_dot} 10{sup 33} 1/cm{sup 2} {center_dot} 1/s with scaled currents of 1400 mA (HER) on 1900 mA (LER). We were typically running about 1300 mA on 1900 mA with 15% more bunches in February (and 1550 mA on 2450 mA with 40% more bunches in May). The bunch …
Date: May 9, 2005
Creator: Colocho, W. S.; Decker, F. J.; Novokhatski, A.; Sullivan, M. K. & Wienands, U.
System: The UNT Digital Library
Calculation of Hamaker constants in non-aqueous fluid media (open access)

Calculation of Hamaker constants in non-aqueous fluid media

Calculations of the Hamaker constants representing the van der Waals interactions between conductor, resistor and dielectric materials are performed using Lifshitz theory. The calculation of the parameters for the Ninham-Parsegian relationship for several non-aqueous liquids has been derived based on literature dielectric data. Discussion of the role of van der Waals forces in the dispersion of particles is given for understanding paste formulation. Experimental measurements of viscosity are presented to show the role of dispersant truncation of attractive van der Waals forces.
Date: May 9, 2000
Creator: BELL,NELSON S. & DIMOS,DUANE B.
System: The UNT Digital Library
Characteristics of CoxTi1-xO2 thin films deposited by MOCVD (open access)

Characteristics of CoxTi1-xO2 thin films deposited by MOCVD

This paper deals with the growth and characterization of ferromagnetic cobalt doped TiO{sub 2} thin films deposited by liquid precursor metal organic chemical vapor deposition (MOCVD) using a new combination of the source materials Co(TMHD){sub 3}, tetrahydrofuran (THF), and titanium isopropoxide (TIP). An array of experiments reveals the intrinsic ferromagnetic nature of the grown films, and suggests that the magnetism is not generated by oxygen vacancies.
Date: May 9, 2008
Creator: McClure, A.; Kayani, A.; Idzerda, Y.U.; Arenholz, E. & Cruz, E.
System: The UNT Digital Library