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Integrated Computing, Communication, and Distributed Control of Deregulated Electric Power Systems
Restructuring of the electricity market has affected all aspects of the power industry from generation to transmission, distribution, and consumption. Transmission circuits, in particular, are stressed often exceeding their stability limits because of the difficulty in building new transmission lines due to environmental concerns and financial risk. Deregulation has resulted in the need for tighter control strategies to maintain reliability even in the event of considerable structural changes, such as loss of a large generating unit or a transmission line, and changes in loading conditions due to the continuously varying power consumption. Our research efforts under the DOE EPSCoR Grant focused on Integrated Computing, Communication and Distributed Control of Deregulated Electric Power Systems. This research is applicable to operating and controlling modern electric energy systems. The controls developed by APERC provide for a more efficient, economical, reliable, and secure operation of these systems. Under this program, we developed distributed control algorithms suitable for large-scale geographically dispersed power systems and also economic tools to evaluate their effectiveness and impact on power markets. Progress was made in the development of distributed intelligent control agents for reliable and automated operation of integrated electric power systems. The methodologies employed combine information technology, control and …
Date:
September 24, 2008
Creator:
Bajura, Richard & Feliachi, Ali
Object Type:
Report
System:
The UNT Digital Library
Intercity Passenger and Freight Rail: Better Data and Communication of Uncertainties Can Help Decision Makers Understand Benefits and Trade-offs of Programs and Policies
A letter report issued by the Government Accountability Office with an abstract that begins "Concerns about the weak economy, congestion in the transportation system, and the potentially harmful effects of air emissions generated by the transportation sector have raised awareness of the potential benefits and costs of intercity passenger and freight rail relative to other transportation modes such as highways. GAO was asked to review (1) the extent to which transportation policy tools that provide incentives to shift passenger and freight traffic to rail may generate emissions, congestion, and economic development benefits and (2) how project benefits and costs are assessed for investment in intercity passenger and freight rail and how the strengths and limitations of these assessments impact federal decision making. GAO reviewed studies; interviewed federal, state, local, and other stakeholders regarding methods to assess benefit and cost information; assessed information on project benefits and costs included in rail grant applications; and conducted case studies of selected policies and programs in the United Kingdom and Germany to learn more about their policies designed to provide incentives to shift traffic to rail."
Date:
February 24, 2011
Creator:
United States. Government Accountability Office.
Object Type:
Report
System:
The UNT Digital Library
TORUS: Theory of Reactions for Unstable iSotopes - Year 1 Continuation and Progress Report
The TORUS collaboration derives its name from the research it focuses on, namely the Theory of Reactions for Unstable iSotopes. It is a Topical Collaboration in Nuclear Theory, and funded by the Nuclear Theory Division of the Office of Nuclear Physics in the Office of Science of the Department of Energy. The funding started on June 1, 2010, it will have been running for nine months by the date of submission of this Annual Continuation and Progress Report on March 1, 2011. The extent of funding was reduced from the original application, and now supports one postdoctoral researcher for the years 1 through 3. The collaboration brings together as Principal Investigators a large fraction of the nuclear reaction theorists currently active within the USA. The mission of the TORUS Topical Collaboration is to develop new methods that will advance nuclear reaction theory for unstable isotopes by using three-body techniques to improve direct-reaction calculations, and, by using a new partial-fusion theory, to integrate descriptions of direct and compound-nucleus reactions. This multi-institution collaborative effort is directly relevant to three areas of interest: the properties of nuclei far from stability; microscopic studies of nuclear input parameters for astrophysics, and microscopic nuclear reaction theory.
Date:
February 24, 2011
Creator:
Arbanas, Goran; Elster, Charlotte; Escher, Jutta; Mukhamedzhanov, Akram; Nunes, Filomena & Thompson, Ian J.
Object Type:
Report
System:
The UNT Digital Library
A numerical theory of lattice gas and lattice Boltzmann methods in the computation of solutions to nonlinear advective-diffusive systems
A numerical theory for the massively parallel lattice gas and lattice Boltzmann methods for computing solutions to nonlinear advective-diffusive systems is introduced. The convergence theory is based on consistency and stability arguments that are supported by the discrete Chapman-Enskog expansion (for consistency) and conditions of monotonicity (in establishing stability). The theory is applied to four lattice methods: Two of the methods are for some two-dimensional nonlinear diffusion equations. One of the methods is for the one-dimensional lattice method for the one-dimensional viscous Burgers equation. And one of the methods is for a two-dimensional nonlinear advection-diffusion equation. Convergence is formally proven in the L{sub 1}-norm for the first three methods, revealing that they are second-order, conservative, conditionally monotone finite difference methods. Computational results which support the theory for lattice methods are presented. In addition, a domain decomposition strategy using mesh refinement techniques is presented for lattice gas and lattice Boltzmann methods. The strategy allows concentration of computational resources on regions of high activity. Computational evidence is reported for the strategy applied to the lattice gas method for the one-dimensional viscous Burgers equation. 72 refs., 19 figs., 28 tabs.
Date:
September 24, 1990
Creator:
Elton, A.B.H.
Object Type:
Report
System:
The UNT Digital Library
Making space for visual literacy in literacy teacher preparation: Preservice teachers coding to design digital books
Article exploring preservice teachers’ coding in the design of a visually-enhanced digital book to reduce the lag between highly visual texts in elementary classrooms and a lack of emphasis on visual literacy in teacher preparation. Findings call for a shift to acknowledge and incorporate visual literacy theories and practices into teacher preparation programs to prepare preservice teachers for digitally literate classrooms.
Date:
July 24, 2021
Creator:
Eutsler, Lauren
Object Type:
Article
System:
The UNT Digital Library
TORUS: Theory of Reactions for Unstable iSotopes Annual Continuation and Progress Report Year-2: March 1, 2011 - February 29, 2012
The TORUS collaboration derives its name from the research it focuses on, namely the Theory of Reactions for Unstable iSotopes. It is a Topical Collaboration in Nuclear Theory, and funded by the Nuclear Theory Division of the Office of Nuclear Physics in the Office of Science of the Department of Energy. The funding supports one postdoctoral researcher for the years 1 through 3. The collaboration brings together as Principal Investigators a large fraction of the nuclear reaction theorists currently active within the USA. The mission of the TORUS Topical Collaboration is to develop new methods that will advance nuclear reaction theory for unstable isotopes by using three-body techniques to improve direct-reaction calculations, and, by using a new partial-fusion theory, to integrate descriptions of direct and compound-nucleus reactions. This multi-institution collaborative effort is directly relevant to three areas of interest: the properties of nuclei far from stability; microscopic studies of nuclear input parameters for astrophysics, and microscopic nuclear reaction theory.
Date:
February 24, 2012
Creator:
Arbanas, Goran; Elster, Charlotte; Escher, Jutta; Mukhamedzanov, Akram; Nunes, Filomena & Thompson, Ian J.
Object Type:
Report
System:
The UNT Digital Library
The Heisenberg representation of quantum computers
Since Shor`s discovery of an algorithm to factor numbers on a quantum computer in polynomial time, quantum computation has become a subject of immense interest. Unfortunately, one of the key features of quantum computers--the difficulty of describing them on classical computers--also makes it difficult to describe and understand precisely what can be done with them. A formalism describing the evolution of operators rather than states has proven extremely fruitful in understanding an important class of quantum operations. States used in error correction and certain communication protocols can be described by their stabilizer, a group of tensor products of Pauli matrices. Even this simple group structure is sufficient to allow a rich range of quantum effects, although it falls short of the full power of quantum computation.
Date:
June 24, 1998
Creator:
Gottesman, D.
Object Type:
Article
System:
The UNT Digital Library
Atomic Energy Levels in Crystals
Report discussing discrete energy levels observed within certain crystals which are due to perturbations of energy levels of the free ion by an electrostatic field arising from the crystal lattice. The analytic procedures for determining the field from the charge configuration are given, and the resulting fields are classified according to their symmetry. After a general survey of group-theoretical ideas, the applicable groups are analyzed in detail, and characters appropriate for both integral and half-integral angular momenta of the free ion are tabulated. Text includes tabulations, equations, and matrices using Wigner and Racah coefficients.
Date:
February 24, 1961
Creator:
Prather, John L.
Object Type:
Report
System:
The UNT Digital Library
Joint Symposium with Religion, Politics and Science - The Media and Violence - From the Viewpoint of a Federal Prosecutor
Lecture given Wednesday, February 24, 1999, 11:00 AM at Abilene Christian University
Date:
February 24, 1999
Creator:
McDaniel, Oliver
Object Type:
Sound
System:
The Portal to Texas History
Socialization on Sustainable Networks: The Case of eBay Green's Facebook
Article explores consumer socialization of sustainable networks based on the theory of consumer socialization, using eBay Green's Facebook presence as a case study.
Date:
April 24, 2020
Creator:
Kim, Haejung; Oh, Kyung Wha & Jung, Hye Jung
Object Type:
Article
System:
The UNT Digital Library
Comments on the kinetic dynamo
It is conjectured that transport by parallel mass flow in a braided magnetic field, rather than hyper-resistivity, drives the dynamo effect after stochasticity is established. In this paper the authors do not attempt a rigorous proof of this conjecture, which requires showing that braiding introduces correlations analogous to those giving rise to the neoclassical bootstrap current. The authors do offer plausible arguments for the conjecture and show that it leads to interesting consequences if true. Namely, magnetic fluctuations would then scale with the magnetic Reynolds number S like {tilde B}/B {approximately} S{sup {minus}1/2} and the Rechester-Rosenbluth thermal diffusivity like {chi}e {proportional_to} S{sup {minus}1} . This scaling would explain the highest temperatures obtained in the CTX spheromak. It also suggests that a fully-bootstrapped current drive experiment could be carried out on-the DIII-D tokamak.
Date:
August 24, 1995
Creator:
Fowler, T.K.
Object Type:
Report
System:
The UNT Digital Library
REACTOR PHYSICS STUDIES FOR THE FINAL CONCEPTUAL DESIGN OF THE ADVANCED TEST REACTOR
A detailed account of the reactor physics studies for the final conceptual design of the Advanced Test Reactor is presented. The diffusion theory methods used for calculations of flux distributions and reactivity effects are described and compared with measurements and with higher order approximations to transport theory. These comparisons show diffusion theory to be adequate for the ATR conceptual design. Two-dimensional flux distributions for a number of shim control conditions and experimental loadings were determined by PDQ-3 and TRANSAC-PDQ. The worths and effects on flux distributions of chemical and of blade type mechanical shim controls were compared. The effects of heavy water and of beryllium reflectors on reactivity and flux pattern were calculated. The time-dependent behavior of the reactor was investigated by use of TURBO and CANDLE. The changes in shim control poison and test and core flux distributions with fuel burnup were calculated and the full-power cycle time estimated. An investigation was made of the xenon transient after a fullpower shutdown and recovery. Results of one- and twodimensional fuel depletion studies are compared. The results of a number of time independent one-dimensional calculations and parametric studies are presented. Some comparisons were made of the results for one-dimensional and two-dimensional …
Date:
March 24, 1961
Creator:
Marsden, R.S. ed.
Object Type:
Report
System:
The UNT Digital Library
Constrained-Transport Magnetohydrodynamics with Adaptive-Mesh-Refinement in CHARM
We present the implementation of a three-dimensional, second order accurate Godunov-type algorithm for magneto-hydrodynamic (MHD), in the adaptivemesh-refinement (AMR) cosmological code CHARM. The algorithm is based on the full 12-solve spatially unsplit Corner-Transport-Upwind (CTU) scheme. Thefluid quantities are cell-centered and are updated using the Piecewise-Parabolic- Method (PPM), while the magnetic field variables are face-centered and areevolved through application of the Stokes theorem on cell edges via a Constrained- Transport (CT) method. The so-called ?multidimensional MHD source terms?required in the predictor step for high-order accuracy are applied in a simplified form which reduces their complexity in three dimensions without loss of accuracyor robustness. The algorithm is implemented on an AMR framework which requires specific synchronization steps across refinement levels. These includeface-centered restriction and prolongation operations and a reflux-curl operation, which maintains a solenoidal magnetic field across refinement boundaries. Thecode is tested against a large suite of test problems, including convergence tests in smooth flows, shock-tube tests, classical two- and three-dimensional MHD tests,a three-dimensional shock-cloud interaction problem and the formation of a cluster of galaxies in a fully cosmological context. The magnetic field divergence isshown to remain negligible throughout. Subject headings: cosmology: theory - methods: numerical
Date:
May 24, 2011
Creator:
Miniatii, Francesco & Martin, Daniel
Object Type:
Article
System:
The UNT Digital Library
Computational modeling of neoclassical and resistive MHD tearing modes in tokamaks
Numerical studies of the nonlinear evolution of MHD-type tearing modes in three-dimensional toroidal geometry with neoclassical effects are presented. The inclusion of neoclassical physics introduces an additional free-energy source for the nonlinear formation of magnetic islands through the effects of a bootstrap current in Ohm`s law. The neoclassical tearing mode is demonstrated to be destabilized in plasmas which are otherwise {Delta}` stable, albeit once an island width threshold is exceeded. The plasma pressure dynamics and neoclassical tearing growth is shown to be sensitive to the choice of the ratio of the parallel to perpendicular diffusivity ({Chi}{parallel}/{Chi}{perpendicular}). The study is completed with a demonstration and theoretical comparison of the threshold for single helicity neoclassical MHD tearing modes, which is described based on parameter scans of the local pressure gradient, the ratio of perpendicular to parallel pressure diffusivities {Chi}{perpendicular}/{Chi}{parallel}, and the magnitude of an initial seed magnetic perturbation.
Date:
June 24, 1996
Creator:
Gianakon, T. A.; Hegna, C. C. & Callen, J. D.
Object Type:
Report
System:
The UNT Digital Library
Operating physics factors with zirconium tubes at the K Reactors
This document lists the physics factors for the K Reactors following the transition to the KV fuel element geometry and zirconium tubes. Each new parameter with the zirconium tube lattice has been calculated relative to the factors used with aluminum tubes and the KIV fuel elements. The purpose of this document is to provide working values for plant assistance use during the transition to the zirconium lattice. In some cases, where there are large uncertainties in the absolute values, the conservative end of the range has been provided for present operational use in safety and control administration. Refinement and publication of ``best`` values for the zirconium lattice based on the extensive experimental and calculational studies are included in future Reactor Physics Unit programs.
Date:
May 24, 1963
Creator:
Tiller, R. E. & Vaughn, A. D.
Object Type:
Report
System:
The UNT Digital Library
Local scrape-off layer control using biased electrodes in NSTX
An experiment was designed to test the theory that biased electrodes can affect the local scrape-off layer (SOL) width by creating a strong radial ExB drift [Cohen, R.H. and Ryutov, D.D, Nucl. Fusion 37, 621 (1997)]. These electrodes were located near the outer midplane in the SOL of the National Spherical Torus Experiment (NSTX). The electrodes were biased at up to �100 Volts, and the radial profile of the plasma between them was measured by an array of Langmuir probes. The biasing caused large changes in the local SOL profiles at least qualitatively consistent with this theory.
Date:
April 24, 2009
Creator:
Zweben, S. J.; Maqueda, R. J.; Roquemore, A. L.; Bush, C. E.; Kaita, R.; Marsala, R. J. et al.
Object Type:
Report
System:
The UNT Digital Library
Information systems and technology transfer programs on geothermal energy and other renewable sources of energy
In order to remain competitive it is necessary to stay informed and use the most advanced technologies available. Recent developments in communication, like the Internet and the World Wide Web, enormously facilitate worldwide data and technology transfer. A compilation of the most important sources of data on renewable energies, especially geothermal, as well as lists of relevant technology transfer programs are presented. Information on how to gain access to, and learn more about them is also given.
Date:
January 24, 1996
Creator:
Lippmann, Marcelo J. & Antunez, Emilio u.
Object Type:
Article
System:
The UNT Digital Library
DATA SET FOR LOW-SPEED REMOTE TERMINALS
Data transmission over telephone lines involves the acceptance of serialized binary data, modulation of the data to a signal suitable to the bandwidth of the telephone. channel, transmission of the signal over the line, reception at the receiving end and demodulation of the signal to reproduce the original binary data. One typical application of data communication is between a low-speed terminal and a computer. In such a case, full-duplex operation is often desirable (i,e., transmission of information on the line in both directions simultaneously). The data set described in this report operates full-duplex and provides for channelization of the telephone line for the simultaneous use of several data sets. The data set can either be coupled to leased telephone lines or acoustically coupled to any telephone.
Date:
June 24, 1965
Creator:
Crockett, E D
Object Type:
Report
System:
The UNT Digital Library
Science & Technology Review December 2007
This month's issue has the following articles: (1) Homeland Security Begins Abroad--Commentary by John C. Doesburg; (2) Out of Harm's Way--New physical protection and accountability systems, together with a focus on security, safeguard nuclear materials in the Russian Federation; (3) A Calculated Journey to the Center of the Earth--Determining the permeability of partially melted metals in a mineral matrix unlocks secrets about the formation of Earth's core; (4) Wireless That Works--Communication technologies using ultrawideband radar are improving national security; and (5) Power to the People--Edward Teller envisioned safe and plentiful nuclear power for peaceful applications.
Date:
October 24, 2007
Creator:
Chinn, D. J.
Object Type:
Report
System:
The UNT Digital Library
Industrial Use of Distributed Generation in Real-Time Energy and Ancillary Service Markets
Industrial consumers of energy now have the opportunity to participate directly in electricity generation. This report seeks to give the reader (1) insights into the various types of generation services that distributed generation (DG) units could provide, (2) a mechanism to evaluate the economics of using DG, (3) an overview of the status of DG deployment in selected states, and (4) a summary of the communication technologies involved with DG and what testing activities are needed to encourage industrial application of DG. Section 1 provides details on electricity markets and the types of services that can be offered. Subsequent sections in the report address the technical requirements for participating in such markets, the economic decision process that an industrial energy user should go through in evaluating distributed generation, the status of current deployment efforts, and the requirements for test-bed or field demonstration projects.
Date:
October 24, 2001
Creator:
Hudson, C.R.
Object Type:
Report
System:
The UNT Digital Library
Online Sag Mill Pulse Measurement and Optimization
The grinding efficiency of semi autogenous milling or ball milling depends on the tumbling motion of the total charge within the mill. Utilization of this tumbling motion for efficient breakage of particles depends on the conditions inside the mill. However, any kind of monitoring device to measure the conditions inside the mill shell during operation is virtually impossible due to the severe environment presented by the tumbling charge. An instrumented grinding ball, which is capable of surviving a few hours and transmitting the impacts it experiences, is proposed here. The spectrum of impacts collected over 100 revolutions of the mills presents the signature of the grinding environment inside mill. This signature could be effectively used to optimize the milling performance by investigating this signature's relation to mill product size, mill throughput, make-up ball size, mill speed, liner profile and ball addition rates. At the same time, it can also be used to design balls and liner systems that can survive longer in the mill. The technological advances made in electronics and communication makes this leap in instrumentation certainly viable. Hence, the instrumented grinding ball offers the ability to qualitatively observe and optimize the milling environment.
Date:
June 24, 2006
Creator:
Rajamani, Raj; Delgadillo, Jose & Duriseti, Vishal
Object Type:
Report
System:
The UNT Digital Library
Scalable High Performance Message Passing over InfiniBand for Open MPI
InfiniBand (IB) is a popular network technology for modern high-performance computing systems. MPI implementations traditionally support IB using a reliable, connection-oriented (RC) transport. However, per-process resource usage that grows linearly with the number of processes, makes this approach prohibitive for large-scale systems. IB provides an alternative in the form of a connectionless unreliable datagram transport (UD), which allows for near-constant resource usage and initialization overhead as the process count increases. This paper describes a UD-based implementation for IB in Open MPI as a scalable alternative to existing RC-based schemes. We use the software reliability capabilities of Open MPI to provide the guaranteed delivery semantics required by MPI. Results show that UD not only requires fewer resources at scale, but also allows for shorter MPI startup times. A connectionless model also improves performance for applications that tend to send small messages to many different processes.
Date:
October 24, 2007
Creator:
Friedley, A.; Hoefler, T.; Leininger, M. L. & Lumsdaine, A.
Object Type:
Article
System:
The UNT Digital Library
Current status and features of the T-2 Nuclear Information Service
This service is run by Group T-2 (Nuclear Theory and Applications) of the Theoretical Division of the Los Alamos National Laboratory, which is operated by the University of California for the US Department of Energy. The author works on nuclear modeling, nuclear data, cross sections, nuclear masses, ENDF, NJOY data processing, nuclear astrophysics, radioactivity, radiation shielding, data for medical radiotherapy, data for high-energy accelerator applications, data and codes for fission and fusion systems, and more. For an introduction to the field of nuclear data and his site, take his Guided Tour. Much of this information can also be accessed using anonymous ftp t2.lanl.gov.
Date:
April 24, 1998
Creator:
MacFarlane, R.E.
Object Type:
Article
System:
The UNT Digital Library
Optimizing Reinjection Strategy at Palinpinon, Philippines Based on Chloride Data
One of the guidelines established for the safe and efficient management of the Palinpinon Geothermal Field is to adopt a production and well utilization strategy such that the rapid rate and magnitude of reinjection fluid returns leading to premature thermal breakthrough would be minimized. To help achieve this goal, sodium fluorescein and radioactive tracer tests have been conducted to determine the rate and extent of communication between the reinjection and producing sectors of the field. The first objective of this paper is to show how the results of these tests, together with information on field geometry and operating conditions were used in algorithms developed in Operations Research to allocate production and reinjection rates among the different Palinpinon wells. Due to operational and economic constraints, such tracer tests were very limited in number and scope. This prevents obtaining information on the explicit interaction between each reinjection well and the producing wells. Hence, the chloride value of the producing well, was tested to determine if use of this parameter would enable identifying fast reinjection paths among different production/reinjection well pairs. The second aim, therefore, of this paper is to show the different methods of using the chloride data of the producing wells …
Date:
March 24, 1992
Creator:
Urbino, Ma. Elena G. & Horne, Roland N.
Object Type:
Article
System:
The UNT Digital Library