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open access

The Function-Altering Effects of Contingency-Specifying Stimuli

Description: Three children between the ages of 3 and 3 1/2 were asked to choose a colored object from an array of 5 colors in a baseline condition. After color preferences were established, stickers, small toys and praise were made contingent on choosing the least preferred color. After the first experimental condition resulted in consistent choosing of the least preferred color, a second experimental condition was implemented. At the beginning of each session a contingency-specifying stimulus (CSS) was pr… more
Date: August 1992
Creator: Ford, Victoria L.
Partner: UNT Libraries

Use of Fading Procedures and Positive Reinforcement to Increase Consumption of Non-Preferred Food in a Child with Autism

Description: Traditionally children with developmental disabilities who develop feeding issues can be at great risk for malnutrition. Failure to eat adequate amounts of food and/or insistence on eating a limited range of foods can be detrimental to a child's health and can lead to other behavioral difficulties. Feeding problems are difficult to treat because high levels of physical prompting can quickly create an aversion to eating as well as cause stress for both parents and children. Behavioral problems t… more
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Date: May 2004
Creator: Vorpahl, Cresse Merchant
Partner: UNT Libraries
open access

Beam shaping element for compact fiber injection systems

Description: Injection of high power, multi-mode laser profiles into a fiber optic delivery system requires controlling a number of injection parameters to maximize throughput and minimize concerns for optical damage both at the entrance and exit faces of the fiber optic. A simple method for simultaneously achieving a compact fiber injection geometry and control of these injection parameters, independent of the input source characteristics, is provided by a refractive lenslet array and simple injection lens… more
Date: January 5, 2000
Creator: Weichman, L.S.; Dickey, F.M. & Shagam, R.N.
Partner: UNT Libraries Government Documents Department
open access

Expanded studies of linear collider final focus systems at the Final Focus Test Beam

Description: In order to meet their luminosity goals, linear colliders operating in the center-of-mass energy range from 3,50 to 1,500 GeV will need to deliver beams which are as small as a few Manometers tall, with x:y aspect ratios as large as 100. The Final Focus Test Beam (FFTB) is a prototype for the final focus demanded by these colliders: its purpose is to provide demagnification equivalent to those in the future linear collider, which corresponds to a focused spot size in the FFTB of 1.7 microns (ho… more
Date: December 1, 1995
Creator: Tenenbaum, Peter Gregory
Partner: UNT Libraries Government Documents Department
open access

Measuring Nonlinear Momentum Compaction in RHIC.

Description: The chromatic nonlinearity parameter, {alpha}{sub 1}, has a strong impact on longitudinal dynamics in the vicinity of transition [1,2,3]. Measurements of the synchrotron frequency as a function of radius are used to constrain the value of {alpha}{sub 1}.
Date: June 18, 2001
Creator: Blaskiewicz, M.; Brennan, J. M.; Cameron, P.; Drees, A.; Kewish, J.; Roser, T. et al.
Partner: UNT Libraries Government Documents Department
open access

Low-dispersion {gamma}{sub t} jump for the main injector

Description: A bipolar {gamma}{sub t}-jump design is reported for the Fermilab Main Injector (Lattice MI-17). The total amount of jump is 1.3 units. Both the betatron and dispersion waves are confined, while the betatron tunes remain nearly unchanged. The Fermilab Main Injector has been designed to overcome some of the unfavorable effects on the particle motion around transition energy. Unlike the Main Ring, the Main Injector has a very large aperture, so that beam low due to scraping can be avoided. The bu… more
Date: May 1, 1995
Creator: Ng, K. Y. & Bogacz, A.
Partner: UNT Libraries Government Documents Department
open access

Beamline smoothing of the Advanced Photon Source

Description: This paper outlines a general beamline smoothing concept based on the use of First Principle Component analysis. Bean-dine smoothing is commonly used for the detection of blunders in the positioning of beam elements and to provide a smooth particle beam path with the fewest adjustments to individual beam components. It also provides the data for assessment of the achieved positioning quality.
Date: June 1, 1995
Creator: Friedsam, H.; Penicka, M. & Zhao, S.
Partner: UNT Libraries Government Documents Department
open access

Continuous contour phase plates for tailoring the focal plane irradiance profile

Description: We present fully continuous phase screens for producing super-Gaussian focal-plane irradiance profiles. Such phase screens are constructed with the assumption of either circular symmetric near-field and far-field profiles or a separable phase screen in Cartesian co-ordinates. In each case, the phase screen is only a few waves deep. Under illumination by coherent light, such phase screens produce high order super-Gaussian profiles in the focal plane with high energy content effects of beam aberr… more
Date: August 9, 1995
Creator: Dixit, S. N.; Rushford, M. C.; Thomas, I. M. & Perry, M. D.
Partner: UNT Libraries Government Documents Department
open access

Magnetic design and measurement of nonlinear multipole magnets for the APT beam expander system

Description: Two prototype nonlinear multipole magnets have been designed for use in the 800-MeV beam test of the APT beam-expansion concept at LANSCE. The iron-dominated magnets each consist of three independent coils, two for producing a predominantly octupole field with a tunable duodecapole component, and one for canceling the residual quadrupole field. Two such magnets, one for shaping each transverse plane, are required to produce a rectangular, uniform beam current density distribution with sharp edg… more
Date: October 1, 1997
Creator: Barlow, David B.; Shafer, Robert E.; Martinez, Ricardo P.; Walstrom, Peter L.; Kahn, S.; Jain, A. et al.
Partner: UNT Libraries Government Documents Department
open access

A Simple X-Ray Focusing Mirror Using Float Glass

Description: In our recent x-ray photon correlation spectroscopy (speckle) experiments at NSLS, one of the challenges is to increase the coherent photon flux through a pinhole, whose size is chosen to match the beam`s horizontal transverse coherence length {ital l{sub h}}. We adopted an approach to vertically focus the x-ray beam so as to match its vertical transverse coherence length {ital l{sub v}}, (at NSLS X13, {ital l{sub v}}{approximately} 50{ital l{sub h}}, {ital l{sub h}}{approximately} 12 {mu}m at … more
Date: October 1, 1996
Creator: Yin, Z.; Berman, L.; Siddons, D. P.; Dierker, S. & Dufresne, E.
Partner: UNT Libraries Government Documents Department
open access

A Comparison of the Effects of Errorful and Errorless Teaching Methods on the Acquisition, Generalization, and Retention of Letter Sound Discriminations in Young Children.

Description: The present study compared the effects of an errorless stimulus shaping procedure to an errorful fluency based procedure for teaching difficult letter sound discriminations using a counterbalanced multielement experimental design. For 2 participants, letters fsteai were taught using the errorless procedure and letters bpdvou were taught using the errorful procedure. For the other 2 participants the conditions were reversed. All participants had considerably fewer errors and fewer trials to crit… more
Date: May 2007
Creator: Doucette, Jessica
Partner: UNT Libraries
open access

Yummy Starts: A Constructional Approach to Food Selectivity with Children with Autism

Description: Food selectivity exhibited by children with autism creates a myriad of barriers for families and children, ranging from social to nutritional. The typical approach to food selectivity is pathological. The pathological approach attempts to eliminate food selectivity through the use of techniques such as escape extinction. While successful in decreasing aspects of food challenges, such as food refusals, the pathological approach does not necessarily establish desired responses to foods or mealtim… more
Date: May 2015
Creator: Cihon, Joseph Harvey
Partner: UNT Libraries
open access

A study of betatron and momentum collimators in RHIC

Description: The Relativistic Heavy Ion Collider (RHIC) has two interaction regions where {beta}* = 1--2m, with large detectors PHENIX and STAR. The transverse and longitudinal emittances are expected to double in size between one to two hours due to intra-beam scattering which may lead to transverse beam loss. Primary betatron collimators are positioned in the ring to allow efficient removal of particles with large betatron amplitudes. The authors have investigated distributions and losses coming from the … more
Date: July 1, 1997
Creator: Trbojevic, D.; Stevens, A. J.; Harrison, M. A.; Dell, F. & Peggs, S.
Partner: UNT Libraries Government Documents Department
open access

The Argonne Wakefield Accelerator: Upgrade scenarios and future experiments

Description: The Argonne Wakefield Accelerator is presently operational and nearing completion of its initial dielectric structure- and plasma-based experimental program. In this paper a number of possible future improvements and directions for the AWA are discussed including photocathode source upgrades, laser pulse and beam shaping options, multiple drive bunch generation, and novel wakefield device measurements. Plans for a 1 GeV demonstration wakefield accelerator will be presented.
Date: October 1, 1997
Creator: Gai, W.; Conde, M.; Konecny, R.; Li, X.; Power, J.; Schoessow, P. et al.
Partner: UNT Libraries Government Documents Department
open access

What Makes a Beam Shaping Problem Difficult?

Description: The authors have discussed the three factors that they believe are the most important in determining the difficulty of a beam shaping problem: scaling, smoothness, and coherence. The arguments have been almost completely based on considering how these factors influence beam shaping lenses that were designed using geometrical optics. However, they believe that these factors control the difficulty of beam shaping problems even if one does not base ones design strategy on geometrical optics. For e… more
Date: July 19, 2000
Creator: Romero, Louis & Dickey, Fred M.
Partner: UNT Libraries Government Documents Department
open access

Generation of multiple bipolar voltage pulses for a phase rotation LIA

Description: In the year 2000, a design concept of a Neutrino Factory based on Muon Storage Ring was studied at FNAL. To treat high energy spread of muons that come out of a target and decay channel and are to be accelerated before they go into the storage ring, a phase rotating scheme using a long-pulse accelerating system has been proposed. In this system accelerating voltage is to be shaped to correct the energy spread. To implement this approach, the pulse power system has been suggested that allows for… more
Date: June 12, 2001
Creator: Terechkine, Yuri & Kazacha, Alexi Sidorov and Vladimir
Partner: UNT Libraries Government Documents Department
open access

Production of U{sup 92+} with an EBIT

Description: A super electron beam ion trap has been used to produce bare U{sup 92+} ions at an electron beam energy of 198 keV. Evaporative cooling with light ions was used to trap a population of 5 {times} 10{sup 4} highly charged uranium ions for many seconds and reduce their temperature to less than 2q eV, suggesting that a very low emittance source of these ions is possible. Roughly 10 U{sup 92+} and 500 U{sup 91+} ions were present in the Super EBIT as determined from x-ray emission spectra of the tra… more
Date: December 1, 1995
Creator: Marrs, R.E.
Partner: UNT Libraries Government Documents Department
open access

Particle beams with uniform transverse distribution

Description: A successfully tested method is described which achieves a more uniform illumination of an extended flat target by the charged particle beam from an accelerator, by proper use of a combination of quadrupole and octupole magneto-optical elements.
Date: October 1, 1996
Creator: Tsoupas, N.; Zucker, M.S.; Snead, C.L. & Ward, T.E.
Partner: UNT Libraries Government Documents Department
open access

Ion beam notcher using a laser

Description: The FNAL LINAC will soon be asked to produce beam at 7.5 Hz. FNAL LINAC extraction involves sweeping the H-minus beam over a Lambertson magnet. The higher repetition rates are expected to activate the Lambertson magnet. A pulsed laser has been installed to make a notch in the beam so that beam will not sweep over the magnet.
Date: July 20, 2001
Creator: Tomlin, Ray
Partner: UNT Libraries Government Documents Department
open access

Microscale Shock Wave Physics Using Photonic Driver Techniques

Description: This report summarizes a multiyear effort to establish a new capability for determining dynamic material properties. By utilizing a significant reduction in experimental length and time scales, this new capability addresses both the high per-experiment costs of current methods and the inability of these methods to characterize materials having very small dimensions. Possible applications include bulk-processed materials with minimal dimensions, very scarce or hazardous materials, and materials … more
Date: January 1, 2002
Creator: Setchell, Robert E.; Trott, Wayne M.; Castaneda, Jaime N.; Farnsworth, A. V., Jr. & Berry, Dante M.
Partner: UNT Libraries Government Documents Department
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