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District Office Leadership Supporting Site-Level Teacher Collaborative Teams (open access)

District Office Leadership Supporting Site-Level Teacher Collaborative Teams

Article describes how previous researchers examining professional learning communities (PLCs) claim that effective building-level PLCs improve teacher collaboration and student achievement. Using an online survey, the authors investigated the claim that district office support enhances the success of site-level PLCs.
Date: October 28, 2023
Creator: Voelkel Jr., Robert H.; Johnson, Christie W. & Nadeem, Fiaz
System: The UNT Digital Library
Efficient separation of xylene isomers by a guest-responsive metal–organic framework with rotational anionic sites (open access)

Efficient separation of xylene isomers by a guest-responsive metal–organic framework with rotational anionic sites

Article demonstrating the adaptively molecular discrimination of xylene isomers by employing a NbOF52−-pillared metal–organic framework (NbOFFIVE-bpy-Ni, also referred to as ZU-61) with rotational anionic sites.
Date: October 28, 2020
Creator: Cui, Xili; Niu, Zheng; Shan, Chuan; Yang, Lifeng; Hu, Jianbo; Wang, Qingju et al.
System: The UNT Digital Library
Adverse Childhood Experiences and Forensic Typologies: Getting Specific about Trauma among Institutionalized Youth (open access)

Adverse Childhood Experiences and Forensic Typologies: Getting Specific about Trauma among Institutionalized Youth

Article on Adverse childhood experiences (ACEs). Utilizing data from 3382 institutionalized delinquents in Texas, logistic regression models indicated multiple associations between ACEs and forensic typologies in both adjusted and unadjusted models, with sexual abuse and physical abuse emerging as the most consistent and robust predictors. Supplemental sensitivity models confirmed the associations between sexual abuse and physical abuse among youth who fit multiple forensic typologies. Models fared poorly at identifying youth who are engaged in fire setting. Implications for total and singular ACEs are discussed, along with how those relate to more clinically meaningful, forensic forms of juvenile delinquency.
Date: October 28, 2021
Creator: Jahic, Ilma; Trulson, Chad R.; Caudill, Jonathan W.; Bonner, Taea; Slemaker, Alexandra & DeLisi, Matt
System: The UNT Digital Library
Crowdsourcing biocuration: the Community Assessment of Community 1 Annotation with Ontologies (CACAO) (open access)

Crowdsourcing biocuration: the Community Assessment of Community 1 Annotation with Ontologies (CACAO)

Article describing an approach to expand biocuration through crowdsourcing with undergraduates in the community-oriented wiki framework for GO annotation called the Gene Ontology Normal Usage Tracking System (GONUTS). This multiplies the number of high-quality annotations in international databases, enriches the coverage of the literature on normal gene function, and pushes the field in new directions.
Date: October 28, 2021
Creator: Ramsey, Jolene; McIntosh, Brenley; Renfro, Daniel; Aleksander, Susan A.; LaBonte, Sandra; Ross, Curtis et al.
System: The UNT Digital Library
Bubbles and their implications for laser-fusion (open access)

Bubbles and their implications for laser-fusion

Bubbles are concentrations of electromagnetic energy in the region of the critical density that force out the plasma to form a void. Since the critical density surface is cratered, absorption may be greater than a smooth surface since a larger area will be available for absorption and the reflected light will have a large probability of restriking the critical density. The distance between bubbles is several wavelengths and consequently they may encourage Rayleigh--Taylor instabilities. The threshold, magnetic field generation, and possible experimental evidence for bubbles are discussed. Also, the competition between sidescatter and self focusing in an entirely underdense plasma is studied and it is found that sidescatter dominates for polarization out of the simulation plane.
Date: October 28, 1975
Creator: Estabrook, K. G. & Valeo, E. J.
System: The UNT Digital Library
Argus Laser Fusion Facility (open access)

Argus Laser Fusion Facility

ARGUS is a two-beam Nd: glass laser system built for laser fusion irradiation experiments. It is the first glass laser system planned and built with the understanding that small-scale beam break-up is the dominant performance limiting factor in obtaining high output power. Accordingly, five vacuum spatial filters are located at strategic intervals along each chain to eliminate the accumulated small-scale filamentation. This strategy permits cascading of amplifiers to obtain a focusable output of more than one terawatt per arm in a spatially clean beam of 20 centimeter diameter. Beam diagnostics which characterize each shot include the time-integrated spatial profile and the time resolved intensity/power at the target. Demonstrated performance to date includes: (1) Peak power in excess of 2 TW at the target is achieved with regularity. (2) Maximum system brightness is in excess of 10/sup 17/ watts/cm/sup 2/ ster. (3) Shot-to-shot pointing stability within 50 ..mu.. radians is achieved over periods of days. (4) Successful target experiments have been performed with pulses of from 30 to 500 ps duration.
Date: October 28, 1976
Creator: Speck, D. R. & Simmons, W. W.
System: The UNT Digital Library
Gain of laser fusion pellets (open access)

Gain of laser fusion pellets

The gain of thermonuclear pellets containing a pusher-tamper of high density high-Z material surrounding the DT fuel is considered. Other significant characteristics of such capsules are briefly mentioned. (MOW)
Date: October 28, 1974
Creator: Nuckolls, J. & Pan, Y. L.
System: The UNT Digital Library
STOMP: A Software Architecture for the Design and Simulation UAV-Based Sensor Networks (open access)

STOMP: A Software Architecture for the Design and Simulation UAV-Based Sensor Networks

This paper presents the Simulation, Tactical Operations and Mission Planning (STOMP) software architecture and framework for simulating, controlling and communicating with unmanned air vehicles (UAVs) servicing large distributed sensor networks. STOMP provides hardware-in-the-loop capability enabling real UAVs and sensors to feedback state information, route data and receive command and control requests while interacting with other real or virtual objects thereby enhancing support for simulation of dynamic and complex events.
Date: October 28, 2002
Creator: Jones, E. D.; Roberts, R. S. & Hsia, T. C. S.
System: The UNT Digital Library
ROBUST TECHNIQUES FOR BACKGROUND SUBTRACTION IN URBAN TRAFFIC VIDEO (open access)

ROBUST TECHNIQUES FOR BACKGROUND SUBTRACTION IN URBAN TRAFFIC VIDEO

Identifying moving objects from a video sequence is a fundamental and critical task in many computer-vision applications. A common approach is to perform background subtraction, which identifies moving objects from the portion of a video frame that differs significantly from a background model. There are many challenges in developing a good background subtraction algorithm. First, it must be robust against changes in illumination. Second, it should avoid detecting non-stationary background objects such as swinging leaves, rain, snow, and shadow cast by moving objects. Finally, its internal background model should react quickly to changes in background such as starting and stopping of vehicles. In this paper, we compare various background subtraction algorithms for detecting moving vehicles and pedestrians in urban traffic video sequences. We consider approaches varying from simple techniques such as frame differencing and adaptive median filtering, to more sophisticated probabilistic modeling techniques. While complicated techniques often produce superior performance, our experiments show that simple techniques such as adaptive median filtering can produce good results with much lower computational complexity.
Date: October 28, 2003
Creator: Kamath, C & Cheung, S S
System: The UNT Digital Library
RF Power and HOM Coupler Tutorial (open access)

RF Power and HOM Coupler Tutorial

Radio frequency (RF) couplers are used on superconducting cavities to deliver RF power for creating accelerating fields and to remove unwanted higher-order mode power for reducing emittance growth and cryogenic load. RF couplers in superconducting applications present a number of interdisciplinary design challenges that need to be addressed, since poor performance in these devices can profoundly impact accelerator operations and the overall success of a major facility. This paper will focus on critical design issues for fundamental and higher order mode (HOM) power couplers, highlight a sampling of reliability-related problems observed in couplers, and discuss some design strategies for improving performance.
Date: October 28, 2003
Creator: Rusnak, B
System: The UNT Digital Library
New 100 mm Gun Assembly Installation at Lawrence Livermore National Laboratory High Explosives Applications Facility (open access)

New 100 mm Gun Assembly Installation at Lawrence Livermore National Laboratory High Explosives Applications Facility

A new 100mm gun assembly was recently installed and tested at Lawrence Livermore National Laboratories located in the High Explosives Applications Facility (HEAF). Thiot Ingenierie performed the design of the replacement barrel, based on improvements to the initial design. This design incorporated barrel and breech sections forged from CLARM series high-strength alloys obtained from Tecphy Corporation and machined by Manufacture de Forage. Part of the improvement of the design was implementing a laser alignment system for quick and accurate barrel alignment checks. This laser is also used to align the target assembly. This paper will detail the design changes incorporated into the installation, the testing process, and future direction of research for the new gun.
Date: October 28, 2003
Creator: Vandersall, K S; Lee, R A; Chiao, P I; Garcia, F; Travis, J O & Forbes, J W
System: The UNT Digital Library
Pre-bomb {Delta}{sup 14}C variability and the Suess Effect in Cariaco Basin Surface Waters as Recorded in Hermatypic Corals (open access)

Pre-bomb {Delta}{sup 14}C variability and the Suess Effect in Cariaco Basin Surface Waters as Recorded in Hermatypic Corals

The {Delta}{sup 14}C content of surface waters in and around the Cariaco Basin were reconstructed from {sup 14}C measurements on sub-annually sampled coral skeletal material. During the late 1930s - early 1940s surface waters within and outside of the Cariaco Basin are similar. Within the Cariaco Basin at Islas Tortugas coral {Delta}{sup 14}C averages -51.9 {+-}3.3 {per_thousand}. Corals collected outside of the basin at Boca de Medio and Los Testigos have {Delta}{sup 14}C values of -53.4 {+-} 3.3 {per_thousand} and -54.3 {+-} 2.6 respectively. Additional {sup 14}C analyses on the Isla Tortugas coral document an {approx} 11 {per_thousand} decrease between {approx}1905 (-40.9 {+-}4.5 {per_thousand}) and {approx}1940. The implied Suess Effect trend (-3 {per_thousand}/decade) is nearly as large as that observed in the atmosphere over the same time period. If we assume that there is little to no fossil fuel {sup 14}CO{sub 2} signature in Cariaco surface waters in {approx}1905, the waters have an equivalent reservoir age of {approx}312 years.
Date: October 28, 2004
Creator: Guilderson, T; Cole, J & Southon, J
System: The UNT Digital Library
HADES, A Code for Simulating a Variety of Radiographic Techniques (open access)

HADES, A Code for Simulating a Variety of Radiographic Techniques

It is often useful to simulate radiographic images in order to optimize imaging trade-offs and to test tomographic techniques. HADES is a code that simulates radiography using ray tracing techniques. Although originally developed to simulate X-Ray transmission radiography, HADES has grown to simulate neutron radiography over a wide range of energy, proton radiography in the 1 MeV to 100 GeV range, and recently phase contrast radiography using X-Rays in the keV energy range. HADES can simulate parallel-ray or cone-beam radiography through a variety of mesh types, as well as through collections of geometric objects. HADES was originally developed for nondestructive evaluation (NDE) applications, but could be a useful tool for simulation of portal imaging, proton therapy imaging, and synchrotron studies of tissue. In this paper we describe HADES' current capabilities and discuss plans for a major revision of the code.
Date: October 28, 2004
Creator: Aufderheide, Maurice B.; Henderson, Gary; Schach von Wittenau, Alexis E.; Slone, Dale M.; Barty, Anton & Martz, Harry E., Jr.
System: The UNT Digital Library
Color sextet quarks and new high-energy interactions (open access)

Color sextet quarks and new high-energy interactions

We review the implications of adding a flavor doublet of color sextet quarks to QCD. Theoretical attractions include -- minimal'' dynamical symmetry breaking of the electroweak interaction, solution of the Strong CP problem via the heavy axion'' [eta][sub 6], and Critical Pomeron Scaling at asymptotic energies. Related experimental phenomena, which there may be evidence for, include -- production of the [eta][sub 6] at LEP, large cross-sections for W[sup +]W[sup [minus]] and Z[sup o]Z[sup o] pairs and very high energy jets in hadron colliders, and a hadronic threshold above which high-energy exotic'' diffractive processes appear in Cosmic Ray events.
Date: October 28, 1992
Creator: White, A. R. (Argonne National Lab., IL (United States)) & Kang, Kyungsik (Brown Univ., Providence, RI (United States))
System: The UNT Digital Library
Advanced Light Source Beam Position Monitor (open access)

Advanced Light Source Beam Position Monitor

The Advanced Light Source (ALS) is a synchrotron radiation facility nearing completion at LBL. As a third-generation machine, the ALS is designed to produce intense light from bend magnets, wigglers, and undulators (insertion devices). The facility will include a 50 MeV electron linear accelerator, a 1.5 GeV booster synchrotron, beam transport lines, a 1--2 GeV storage ring, insertion devices, and photon beam lines. Currently, the beam injection systems are being commissioned, and the storage ring is being installed. Electron beam position monitors (BPM) are installed throughout the accelerator and constitute the major part of accelerator beam diagnostics. The design of the BPM instruments is complete, and 50 units have been constructed for use in the injector systems. We are currently fabricating 100 additional instruments for the storage ring. In this paper I discuss engineering fabrication, testing and performance of the beam pickup electrodes and the BPM electronics.
Date: October 28, 1991
Creator: Hinkson, J.
System: The UNT Digital Library
Thermal effects and mirror surface figure requirements for a diagnostic beamline at the Advanced Light Source (open access)

Thermal effects and mirror surface figure requirements for a diagnostic beamline at the Advanced Light Source

An imaging beamline based on a Kirkpatrick-Baez mirror configuration has been designed to image the electron beam in the ALS storage ring, to measure its size and shape. The electron beam emittance will be small ({epsilon}h = 3.4 {times} 10{sup {minus}9} m rad) and the quality of the image is extremely sensitive to surface figure distortion of the mirrors. Thermal distortions and surface temperatures have been calculated for radiatively cooled mirrors of various materials in a search for a simple design which avoids water cooling. The choice of mirror material and the thermal and mechanical design is discussed. 6 refs.
Date: October 28, 1991
Creator: Warwick, T. & Sharma, S.
System: The UNT Digital Library
Water cooled metal optics for the Advanced Light Source (open access)

Water cooled metal optics for the Advanced Light Source

The program for providing water cooled metal optics for the Advanced Light Source at Berkeley is reviewed with respect to fabrication and metrology of the surfaces. Materials choices, surface figure and smoothness specifications, and metrology systems for measuring the plated metal surfaces are discussed. Results from prototype mirrors and grating blanks will be presented, which show exceptionally low microroughness and mid-period error. We will briefly describe out improved version of the Long Trace Profiler, and its importance to out metrology program. We have completely redesigned the mechanical, optical and computational parts of the profiler system with the cooperation of Peter Takacs of Brookhaven, Continental Optical, and Baker Manufacturing. Most important is that one of our profilers is in use at the vendor to allow testing during fabrication. Metrology from the first water cooled mirror for an ALS beamline is presented as an example. The preplating processing and grinding and polishing were done by Tucson Optical. We will show significantly better surface microroughness on electroless nickel, over large areas, than has been reported previously.
Date: October 28, 1991
Creator: McKinney, W. R.; Irick, S. C. & Lunt, D. L. J.
System: The UNT Digital Library
Color Sextet Quarks and New High-Energy Interactions (open access)

Color Sextet Quarks and New High-Energy Interactions

We review the implications of adding a flavor doublet of color sextet quarks to QCD. Theoretical attractions include -- ``minimal`` dynamical symmetry breaking of the electroweak interaction, solution of the Strong CP problem via the ``heavy axion`` {eta}{sub 6}, and Critical Pomeron Scaling at asymptotic energies. Related experimental phenomena, which there may be evidence for, include -- production of the {eta}{sub 6} at LEP, large cross-sections for W{sup +}W{sup {minus}} and Z{sup o}Z{sup o} pairs and very high energy jets in hadron colliders, and a hadronic threshold above which high-energy ``exotic`` diffractive processes appear in Cosmic Ray events.
Date: October 28, 1992
Creator: White, Alan R. & Kang, Kyungsik
System: The UNT Digital Library
3D field calculation of the GEM prototype magnet and comparison with measurements (open access)

3D field calculation of the GEM prototype magnet and comparison with measurements

The proposed 4 GeV Electron Microtron (GEM) is designed to fill the existing buildings left vacant by the demise of the Zero Gradient Synchrotron (ZGS) accelerator. One of the six large dipole magnets is shown as well as the first 10 electron orbits. A 3-orbit prototype magnet has been built. The stepped edge of the magnet is to keep the beam exiting perpendicular to the pole. The end guards that wrap around the main coils are joined together by the 3 shield plates. The auxiliary coils are needed to keep the end guards and shield plates from saturating. A 0.3 cm Purcell filter air gap exists between the pole and the yoke. Can anyone question this being a truly three-dimensional magnetostatic problem. The computer program TOSCA, developed at the Rutherford Appleton Laboratory by the Computing Applications Group, was used to calculate this magnet and the results have been compared with measurements.
Date: October 28, 1983
Creator: Lari, R.J.
System: The UNT Digital Library
A new one-detector analysis method for rapid high precision plutonium isotopic measurements (open access)

A new one-detector analysis method for rapid high precision plutonium isotopic measurements

A new method has been developed that achieves plutonium isotopic analysis precisions of better than 2% in counting times of only a few minutes, using only the 59- to 208-keV energy region of a spectrum. This breakthrough was achieved by developing a unique but highly accurate method for delineating the overall ''intrinsic'' efficiency curve, including the plutonium K-shell absorption discontinuity at 121 keV. Consequently, the measured 129- and 148-keV peak intensities can now be used to reliably determine the relative abundances of /sup 239/Pu and /sup 241/Pu. The intense 94- to 104-keV region is also analyzed, providing accurate data for the other isotopes of interest. 5 refs., 3 figs., 2 tabs.
Date: October 28, 1986
Creator: Gunnink, R.
System: The UNT Digital Library
Cryogenic system design for a compact tokamak reactor (open access)

Cryogenic system design for a compact tokamak reactor

The International Tokamak Engineering Reactor (ITER) is a program presently underway to design a next-generation tokamak reactor. The cryogenic system for this reactor must meet unusual and new requirements. Unusually high heat loads (100 kW at 4.5 K) must be handled because neutron shielding has been limited to save space in the reactor core. Also, large variations in the cryogenics loads occur over short periods of time because of the pulsed nature of some of the operating scenarios. This paper describes a workable cryogenic system design for a compact tokamak reactor such as ITER. A design analysis is presented dealing with a system that handles transient loads, coil quenches, reactor cool-down and the effect of variations in helium-supply temperatures on the cryogenic stability of the coils. 5 refs., 4 figs., 1 tab.
Date: October 28, 1988
Creator: Slack, D. S.; Kerns, J. A. & Miller, J. R.
System: The UNT Digital Library
Radiation imposed limits on superconducting magnets: A data base for copper stabilizers (open access)

Radiation imposed limits on superconducting magnets: A data base for copper stabilizers

Two of eight differently prepared copper stabilizer samples, previously irradiated in the RTNS-II at LLNL, the IPNS-1 and the BSR at ORNL, have been irradiated to a fluence of 1.33 /times/ 10/sup 22/ n/m/sup 2/ at RTNS-II. During the course of the irradiation the samples were periodically removed (without warming) for measurements of the transverse magnetoresistance and returned for continued irradiation. This experiment extends the range of neutron-irradiation-induced resistivity by a factor of five over the previous experiments. A simple model is developed which reproduces the magnetoresistance results of all the experiments to an accuracy of 2.5%. 13 refs., 6 figs.
Date: October 28, 1987
Creator: Guinan, M.W.; Hahn, P.A.; Klabunde, C.E. & Coltman, R.R. Jr.
System: The UNT Digital Library
Calculational comparison of DT, neon, and argon implosions (open access)

Calculational comparison of DT, neon, and argon implosions

A number of laboratories have been doing laser driven implosions of pure neon and argon gas as a diagnostic of the peak imploded conditions. The relationship of these implosions to DT implosions has been unclear. This paper will explore the physics of these higher Z gases and show that they are fundamentally easier to compress than DT gas. Specifically, this paper will show that, for the same initial mass density, and the same capsule design and drive conditions, the calculated peak compressed density is dependent on the type of fill gas, being substantially higher for Ne and Ar implosions than for DT implosions.
Date: October 28, 1980
Creator: Stevens, J. C.
System: The UNT Digital Library
Advanced Light Source beam position monitor (open access)

Advanced Light Source beam position monitor

The Advanced Light Source (ALS) is a synchrotron radiation facility nearing completion at LBL. As a third-generation machine, the ALS is designed to produce intense light from bend magnets, wigglers, and undulators (insertion devices). The facility will include a 50 MeV electron linear accelerator, a 1.5 GeV booster synchrotron, beam transport lines, a 1--2 GeV storage ring, insertion devices, and photon beam lines. Currently, the beam injection systems are being commissioned, and the storage ring is being installed. Electron beam position monitors (BPM) are installed throughout the accelerator and constitute the major part of accelerator beam diagnostics. The design of the BPM instruments is complete, and 50 units have been constructed for use in the injector systems. We are currently fabricating 100 additional instruments for the storage ring. In this paper I discuss engineering fabrication, testing and performance of the beam pickup electrodes and the BPM electronics.
Date: October 28, 1991
Creator: Hinkson, J.
System: The UNT Digital Library