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ADIFOR Exception Handling. ADIFOR Working Note No. 3
Automatic differentiation uses recurrence relations based on the rules of calculus. Consequently, the results are guaranteed to be correct only in the relevant mathematical assumptions are satisfied at least in a neighborhood of the current argument. Computer programs may violate these conditions by branching or by calling intrinsic functions such as abs, max, sqrt, and asin at point where their derivative is undefined or infinite. The resulting dependence between the program`s input and output variables may still be differentiable, because branch vales fit together smoothly or nondifferentiabilities cancel each other out. We have two objectives. First, we would like to assure the user that the function being evaluated is indeed locally differentiable because all intrinsics are evaluated at smooth arguments and none of the branching tests are critical. Second, the derivative program should run even when the assumptions of the chain rule are not strictly satisfied. In this case, the numerical results represent at least generalized derivations under reasonable (but usually unverifiable) regularity assumptions. To achieve these two goals, we must take into account the effects of finite-precision arithmetic. This paper addresses the detection and handling of exceptions. It is an exception in the ADIFOR-generated code to evaluate a function …
Date:
January 1, 1992
Creator:
Bischof, C.; Corliss, G. & Griewank, A.
Object Type:
Report
System:
The UNT Digital Library
ADIFOR: Fortran source translation for efficient derivatives
The numerical methods employed in the solution of many scientific computing problems require the computation of derivatives of a function f: R{sup n} {yields} R{sup m}. Both the accuracy and the computational requirements of the derivative computation are usually of critical importance for the robustness and speed of the numerical method. ADIFOR (Automatic Differentiation In FORtran) is a source translation tool implemented using the data abstractions and program analysis capabilities of the ParaScope Parallel Programming Environment. ADIFOR accepts arbitrary Fortran-77 code defining the computation of a function and writes portable Fortran-77 code for the computation of its derivatives. In contrast to previous approaches, ADIFOR views automatic differentiation as a process of source translation that exploits computational context to reduce the cost of derivative computations. Experimental results show that ADIFOR can handle real-life codes, providing exact derivatives with a running time that is competitive with the standard divided-difference approximations of derivatives and which may perform orders of magnitude faster than divided-differences in cases. The computational scientist using ADIFOR is freed from worrying about the accurate and efficient computation of derivatives, even for complicated functions,'' and hence, is able to concentrate on the more important issues of algorithm design or system modeling. …
Date:
January 1, 1992
Creator:
Bischof, C.; Corliss, G.; Griewank, A.; Hovland, P. (Argonne National Lab., IL (United States)) & Carle, A. (Rice Univ., Houston, TX (United States). Center for Research on Parallel Computation)
Object Type:
Article
System:
The UNT Digital Library
ADIFOR Working Note #2: Using ADIFOR to Compute Dense and Sparse Jacobians
ADIFOR is a source translator that, given a collection of Fortran subroutines for the computation of a ``function,`` produces Fortran code for the computation of the derivatives of this function. More specifically, ADIFOR produces code to compute the matrix-matrix product JS, where J is the Jacobian of the ``function`` with respect to the user-defined independent variables, and S is the composition of the derivative objects corresponding to the independent variables. This interface is flexible; by setting S = x, one can compute the matrix-vector product Jx, or by setting S = I, one can compute the whole Jacobian J. Other initializations of S allow one to exploit a known sparsity structure of J. This paper illustrates the proper initialization of ADIFOR-generated derivative codes and the exploitation of a known structure of J.
Date:
January 1, 1992
Creator:
Bischof, C. & Hovland, P.
Object Type:
Report
System:
The UNT Digital Library
Adjacency-blurring-effect of scenes modeled by the radiosity method
In this paper we describe a method to simulate images through a scattering atmosphere. We compute the scattering of light from adjacent surfaces into the field-of-view (FOV) with the extended radiosity method. Our simulation takes aerosol scattering phase functions and ground bidirectional reflectance distributions (BRDF) into account. 10 refs.
Date:
January 1, 1992
Creator:
Borel, C.C. & Gerstl, S.A.W.
Object Type:
Article
System:
The UNT Digital Library
The ADRIA project for high intensity radioactive beams production
A proposal of an accelerator complex (ADRIA) for the Laboratori Nazionali di Legnaro (LNL) is described in this report. The main components of the complex are a Heavy Ion Injection system and two rings, a Booster and a Decelerator, both with a maximum rigidity of 22.25 Tm, connected by a Transfer Line where exotic proposal has two main goals consisting in the isotopes are produced and selected. The proposal has two main goals consisting in the acceleration of stable ion species up to kinetic energies of the order of few GeV/u, at a repetition rate of 10 Hz with intensities of about 10[sup 12] ions per second, for fixed target experiments in nuclear physics and for the production of fully stripped radioactive beams, using particle fragmentation method for nuclear spectroscopy experiments. Fragments are accumulated in the Decelerator, with intensities 10[sup 8] [divided by] 10[sup 9] ions/s, cooled and delivered at the production energies or decelerated down to energies of few MeV/u, in proximity of the Coulomb barrier.
Date:
January 1, 1992
Creator:
Bisoffi, G.; Cavenago, M.; Dainelli, A.; Facco, A.; Fortuna, G.; Lombardi, A. et al.
Object Type:
Article
System:
The UNT Digital Library
Adsorption of a binary gas mixture which laterally interacts on a random heterogeneous surface
Analytical expressions for the adsorption of a binary gas mixture which laterally interacts on a heterogeneous surface are developed. The lateral interactions are of the Bragg-Williams type and the surface heterogeneity is modeled via a random distribution of sites described by a uniform distribution of Henry's Law constants. The parametric study shows that complex phase behavior can be predicted, including azeotropes and sigmoidal shaped X-Y diagrams. Also, this model may be useful for modeling and designing adsorption processes as it requires few iterations to simultaneously solve the implicit and coupled algebraic expressions.
Date:
January 1, 1992
Creator:
Ritter, James A.
Object Type:
Article
System:
The UNT Digital Library
Adsorption of aniline and toluidines on montmorillonite: Implications for the disposal of shale oil production wastes
Bentonite clay liners are commonly employed to mitigate the movement of contaminants from waste disposal sites. Solid and liquid waste materials that arise from the production of shale oil contain a vast array of organic compounds. Common among these compounds are the aromatic amines. in order to assess the ability of clay liner material to restrict organic compound mobility, the adsorption of aniline and o-, m-, and p-toluidine on Ca{sup 2+} - and K{sup +}-saturated Wyoming bentonite was investigated. Adsorption experiments were performed under conditions of varied pH, ionic strength, and dominate electrolyte cation and anion. organic adsorption on Ca{sup 2+} - and K{sup +}-saturated montmorillonite is pH dependent. For any given organic compound, maximum adsorption increases with decreasing ionic strength. organic compound adsorption is inhibited in the presence of sulfate and is greater in the Ca{sup 2+} systems than in the K{sup +} systems at any given ionic strength. High salt content and K{sup +} collapse the bentonite layers and limit access to and compete for adsorption sites. The K{sup +} ion is also more difficult to displace than Ca{sup 2+} from interlayer positions. Fourier transform infrared spectroscopic data show that the aniline compounds are adsorbed on bentonite through …
Date:
January 1, 1992
Creator:
Essington, M. E.; Bowen, J. M.; Wills, R. A. & Hart, B. K.
Object Type:
Report
System:
The UNT Digital Library
Adsorption of aniline and toluidines on montmorillonite: Implications for the disposal of shale oil production wastes
Bentonite clay liners are commonly employed to mitigate the movement of contaminants from waste disposal sites. Solid and liquid waste materials that arise from the production of shale oil contain a vast array of organic compounds. Common among these compounds are the aromatic amines. in order to assess the ability of clay liner material to restrict organic compound mobility, the adsorption of aniline and o-, m-, and p-toluidine on Ca[sup 2+] - and K[sup +]-saturated Wyoming bentonite was investigated. Adsorption experiments were performed under conditions of varied pH, ionic strength, and dominate electrolyte cation and anion. organic adsorption on Ca[sup 2+] - and K[sup +]-saturated montmorillonite is pH dependent. For any given organic compound, maximum adsorption increases with decreasing ionic strength. organic compound adsorption is inhibited in the presence of sulfate and is greater in the Ca[sup 2+] systems than in the K[sup +] systems at any given ionic strength. High salt content and K[sup +] collapse the bentonite layers and limit access to and compete for adsorption sites. The K[sup +] ion is also more difficult to displace than Ca[sup 2+] from interlayer positions. Fourier transform infrared spectroscopic data show that the aniline compounds are adsorbed on bentonite through …
Date:
January 1992
Creator:
Essington, M. E.; Bowen, J. M.; Wills, R. A. & Hart, B. K.
Object Type:
Report
System:
The UNT Digital Library
[Adult Man with Drum at Salute to Youth Awards Program]
Photograph of an unidentified male musician during the Salute to Youth Awards Program, an event awarding scholarships to students. The man wears a blue hat, white shirt, pants, and a gold band necklace. A black strap is over his left shoulder and ties to the djembe drum in between his legs. Behind him, a wooden podium with the Martin Luther King Middle School crest can be seen. Additionally, a green and white banner that reads "San Antonio Chapter of Links, INC" has been placed on long curtains. Hand-written text on the back of the photograph identifies the musician, but it cannot be read with certainty.
Date:
1992
Creator:
Links, Inc. San Antonio Chapter.
Object Type:
Photograph
System:
The Portal to Texas History
Advanced Coal Liquefaction Research and Development Facility, Wilsonville, Alabama
This report presents the results of Run 260 performed at the Advanced Coal Liquefaction R D Facility in Wilsonville. The run was started on July 17, 1990 and continued until November 14, 1990, operating in the Close-Coupled Integrated Two-Stage Liquefaction mode processing Black Thunder mine subbituminous coal (Wyodak-Anderson seam from Wyoming Powder River Basin). Both thermal/catalytic and catalytic/thermal tests were performed to determine the methods for reducing solids buildup in a subbituminous coal operation, and to improve product yields. A new, smaller interstage separator was tested to reduce solids buildup by increasing the slurry space velocity in the separator. In order to obtain improved coal and resid conversions (compared to Run 258) full-volume thermal reactor and 3/4-volume catalytic reactor were used. Shell 324 catalyst, 1/16 in. cylindrical extrudate, at a replacement rate of 3 lb/ton of MF coal was used in the catalytic stage. Iron oxide was used as slurry catalyst at a rate of 2 wt % MF coal throughout the run. (TNPS was the sulfiding agent.)
Date:
January 1, 1992
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Advanced Coal Liquefaction Research and Development Facility, Wilsonville, Alabama. Run 260 with Black Thunder Mine subbituminous coal: Technical progress report
This report presents the results of Run 260 performed at the Advanced Coal Liquefaction R&D Facility in Wilsonville. The run was started on July 17, 1990 and continued until November 14, 1990, operating in the Close-Coupled Integrated Two-Stage Liquefaction mode processing Black Thunder mine subbituminous coal (Wyodak-Anderson seam from Wyoming Powder River Basin). Both thermal/catalytic and catalytic/thermal tests were performed to determine the methods for reducing solids buildup in a subbituminous coal operation, and to improve product yields. A new, smaller interstage separator was tested to reduce solids buildup by increasing the slurry space velocity in the separator. In order to obtain improved coal and resid conversions (compared to Run 258) full-volume thermal reactor and 3/4-volume catalytic reactor were used. Shell 324 catalyst, 1/16 in. cylindrical extrudate, at a replacement rate of 3 lb/ton of MF coal was used in the catalytic stage. Iron oxide was used as slurry catalyst at a rate of 2 wt % MF coal throughout the run. (TNPS was the sulfiding agent.)
Date:
January 1, 1992
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Advanced direct coal liquefaction concepts
During the first quarter of FY 1993, the Project proceeded close to the Project Plan. The analysis of the feed material has been completed as far as possible. Some unplanned distillation was needed to correct the boiling range of the Black Thunder solvent used during the autoclave tests. Additional distillation will be required if the same solvent is to be used for the bench unit tests. A decision on this is still outstanding. The solvent to be used with Illinois No. 6 coal has not yet been defined. As a result, the procurement of the feed and the feed analysis is somewhat behind schedule. Agglomeration tests with Black Thunder coal indicates that small agglomerates can be formed. However, the ash removal is quite low (about 10%), which is not surprising in view of the low ash content of the coal. The first series of autoclave tests with Black Thunder coal was completed as planned. Also, additional runs are in progress as repeats of previous runs or at different operating conditions based on the data obtained so far. The results are promising indicating that almost complete solubilization (close to 90%) of Black Thunder coal can be achieved in a CO/H[sub 2]O …
Date:
January 1, 1992
Creator:
Berger, D. J.; Parker, R. J. & Simpson, P. L.
Object Type:
Report
System:
The UNT Digital Library
Advanced lightweight ceramic candle filter module
To determine the economic effect of light weight ceramics, several sizes of filters were cost estimated for operation at 217.5 psi (15 bar) based on the use of all light weight ceramics (Fibro/Fibro) vs. the use of cooled alloy (RA300) tubesheets and silicon carbide candles (Alloy/SiC). A jet pulse delivery system was included in both estimates. The Fibro/Fibro system was estimated with the plenum design while the Alloy/SiC system was based on header/nozzle design. Battery limits were the filters and jet pulse delivery systems, Ex-works, with no main valves or dust removal systems. It was found that the cost of Fibro/Fibro components were consistently lower than the cost of the Alloy/SiC components; this comparison is illustrated in Figure 8.
Date:
January 1, 1992
Creator:
Zievers, J.F. & Eggerstedt, P.
Object Type:
Article
System:
The UNT Digital Library
Advanced Neutron Source (ANS) Project Progress report, FY 1991
This report discusses the following about the Advanced Neutron Source: Project Management; Research and Development; Fuel Development; Corrosion Loop Tests and Analyses; Thermal-Hydraulic Loop Tests; Reactor Control and Shutdown Concepts; Critical and Subcritical Experiments; Material Data, Structural Tests, and Analysis; Cold-Source Development; Beam Tube, Guide, and Instrument Development; Hot-Source Development; Neutron Transport and Shielding; I & C Research and Development; Design; and Safety.
Date:
January 1, 1992
Creator:
Campbell, J. H.; Selby, D. L.; Harrington, R. M. & Thompson, P. B.
Object Type:
Report
System:
The UNT Digital Library
Advanced Neutron Source (ANS) Project Progress report, FY 1991
This report discusses the following about the Advanced Neutron Source: Project Management; Research and Development; Fuel Development; Corrosion Loop Tests and Analyses; Thermal-Hydraulic Loop Tests; Reactor Control and Shutdown Concepts; Critical and Subcritical Experiments; Material Data, Structural Tests, and Analysis; Cold-Source Development; Beam Tube, Guide, and Instrument Development; Hot-Source Development; Neutron Transport and Shielding; I C Research and Development; Design; and Safety.
Date:
January 1, 1992
Creator:
Campbell, J. H. (ed.) (Oak Ridge National Lab., TN (United States)); Selby, D. L.; Harrington, R. M. (Oak Ridge National Lab., TN (United States)) & Thompson, P. B. (Martin Marietta Energy Systems, Inc., (United States). Engineering Division)
Object Type:
Report
System:
The UNT Digital Library
Advanced NMR Approaches in the Characterization of Coal
A considerable effort in this project during the past few months has been focussed on the development of [sup 1]H and [sup 13]C NMR imaging techniques to yield spatially-resolved chemical shift (structure) information on coal. In order to yield the chemical shift information, a solid-state NMR imaging technique must include magic-angle spinning, so rotating gradient capabilities are indicated. A [sup 13]C MAS imaging probe and a [sup 1]H MAS imaging probe and the circuitry necessary for rotating gradients have been designed and constructed. The [sup 1]H system has already produced promising preliminary results, which are briefly described in this report.
Date:
January 1, 1992
Creator:
Maciel, G. E.
Object Type:
Report
System:
The UNT Digital Library
Advanced Nmr Approaches in the Characterization of Coal
The paper submitted earlier on the use of (bicyclo[3.2.1]4pyrrolidino-N-methyl-octan-8-one triflate) ([sup 13]CO-123) as a [sup 13]C intensity standard was accepted for publication. Subsequently, [sup 13]CO-321 was used in this manner for quantitative [sup 13]C CP-MAS NMR analysis (including spin counting) of Argonne Premium coals. The cross-polarization time constants, T[sub CH], and the rotating-frame proton spin-lattice relaxation times, T[sub 1p][sup H], were determined for each major peak of each coal via a combination of variable contact-time and variable spin-lock (T[sub 1p][sup H]) experiments. Two or three components of rotating-frame [sup 1]H relaxation decay and two or three components of T[sub CH] behavior were observed for each major [sup 13]C peak of each coal. These data were used to determine the number of carbon atoms detected in each coal; these values are in the range between 77% and 87% of the amount of carbon known to be in each coal from elemental analysis data, except for Pocahontas No. 3, for which only 50% of the carbon was detected. In an attempt to use [sup 1]H CRAMPS to elucidate chemical functionality in coal, pyridine-saturated samples of the Argonne Premium coals were examined in detail in terms of their [sup 1]H CRAMPS NMR spectra. …
Date:
January 1, 1992
Creator:
Maciel, G. E.
Object Type:
Report
System:
The UNT Digital Library
Advanced NMR-based techniques for pore structure analysis of coal
One of the main problems in coal utilization is the inability to properly characterize its complex pore structure. Coals typically have micro/ultra-micro pores but they also exhibit meso and macroporosity. We believe that measurement of the NMR parameters of various gas phase and adsorbed phase NMR active probes can provide the resolution to this problem. We will investigate the dependence of the common NMR parameters such as chemical shifts and relaxation times of several different nuclei and compounds on the pore structure of model microporous solids, carbons, and coals. In particular, we will study the interaction between several small molecules ({sup 129}Xe, {sup 3}He, {sup 2}H{sub 2}, {sup 14}N{sub 2}, {sup 14}NH{sub 3}, {sup 15}N{sub 2}, {sup 13}CH{sub 4}, {sup 13}CO{sub 2}) and the pore surfaces in coals. These molecules have been selected for their chemical and physical properties. A special NMR probe will be constructed which will allow the concurrent measurement of NMR properties and adsorption uptake at a variety of temperatures. All samples will be subjected to a suite of conventional'' pore structure analyses. These include nitrogen adsorption at 77 K with BET analysis, C0{sub 2} and CH{sub 4} adsorption at 273 K with D-R (Dubinin-Radushkevich) analysis, helium …
Date:
January 1, 1992
Creator:
Smith, D. M.
Object Type:
Report
System:
The UNT Digital Library
Advanced NMR-based techniques for pore structure analysis of coal
One of the main problems in coal utilization is the inability to properly characterize its complex pore structure. Coals typically have micro/ultra-micro pores but they also exhibit meso and macroporosity. Conventional pore size techniques (adsorption/condensation, mercury porosimetry) are limited because of this broad pore size range, microporosity, reactive nature of coal, samples must be completely dried, and network/percolation effects. Small angle scattering is limited because it probes both open and closed pores. Although one would not expect any single technique to provide a satisfactory description of a coal's structure, it is apparent that better techniques are necessary. We believe that measurement of the NMR parameters of various gas phase and adsorbed phase NMR active probes can provide the resolution to this problem. We will investigate the dependence of the common NMR parameters such as chemical shifts and relaxation times of several different nuclei and compounds on the pore structure of model microporous solids, carbons, and coals. In particular, we will study the interaction between several small molecules and the pore surfaces in coals. These molecules have been selected for their chemical and physical properties. A special NMR probe will be constructed which will allow the concurrent measurement of NMR properties …
Date:
January 1, 1992
Creator:
Smith, Douglas M.
Object Type:
Report
System:
The UNT Digital Library
Advanced NMR-based techniques for pore structure analysis of coal
One of the main problems in coal utilization is the inability to properly characterize its complex pore structure. Coals typically have micro/ultra-micro pores but they also exhibit meso and macroporosity. Conventional pore size techniques (adsorption/condensation, mercury porosimetry) are limited because of this broad pore size range, microporosity, reactive nature of coal, samples must be completely dried, and network/percolation effects. Small angle scattering is limited because it probes both open and closed pores. Although one would not expect any single technique to provide a satisfactory description of a coal's structure, it is apparent that better techniques are necessary. We believe that measurement of the NMR parameters of various gas phase and adsorbed phase NMR active probes can provide the resolution to this problem. We now have two suites of well-characterized microporous materials including oxides (zeolites and silica gel) and activated carbons from our industrial partner, Air Products in Allentown, PA. Our current work may be divided into three areas: small-angle X-ray scattering (SAXS), adsorption, and NMR.
Date:
January 1, 1992
Creator:
Smith, Douglas M.
Object Type:
Report
System:
The UNT Digital Library
The Advanced Photon Source: A status report
The Advanced Photon Source (APS) currently under construction at Argonne National Laboratory is scheduled for completion in early 1996. Both conventional facilities construction and technical fabrication is well underway. An update on the current state of civil construction as well as progress on storage ring and beamline technical component development will be presented. User activities have also proceeded at a rapid pace, particularly over the last year. In response to a call for Proposals for sectors, the APS received proposals for over twenty sectors from prospective Collaborative Access Teams (CATs). It is anticipated that beamline construction in the experiment hall could begin in approximately 18 months.
Date:
January 1, 1992
Creator:
Mills, D.M.
Object Type:
Article
System:
The UNT Digital Library
The Advanced Photon Source: A status report
The Advanced Photon Source (APS) currently under construction at Argonne National Laboratory is scheduled for completion in early 1996. Both conventional facilities construction and technical fabrication is well underway. An update on the current state of civil construction as well as progress on storage ring and beamline technical component development will be presented. User activities have also proceeded at a rapid pace, particularly over the last year. In response to a call for Proposals for sectors, the APS received proposals for over twenty sectors from prospective Collaborative Access Teams (CATs). It is anticipated that beamline construction in the experiment hall could begin in approximately 18 months.
Date:
January 1, 1992
Creator:
Mills, D. M.
Object Type:
Article
System:
The UNT Digital Library
Advanced Scientific Computing Environment Team
The mission of the ASCENT (Advanced Scientific Computing EnvironmenT) Team is continually keep pace with, evaluate, and select emerging computing technologies to define and implement prototypic scientific computing environments that maximize the ability of scientists and engineers to manage scientific data. These environments are to be implemented in a manner consistent with the site computing architecture and standards and strategic plans for scientific computing. A broad, long term, goal of the ASCENT Team is to provide a computing environment that will let scientists and engineers function at the higher level of abstraction that is their actual area of technical expertise. The scientist/engineer should be able to solve problems by interacting with conceptual representations drawn directly from the scientific and engineering domains. In this environment the scientist/engineer (i.e., the problem solver'') builds the problem model with reusable virtual objects having associated attributes and behaviors, including any real or artificial constraints. The problem solver could then test the model by perturbing it interactively and observing quantitative (archived experimental measurements; simulated or computed data) and/or qualitative (trends, approximations) responses. Such an environment would greatly aid the solution and understanding of scientific and engineering problems. This report discusses the proposed system, program, graphic tools …
Date:
January 1, 1992
Creator:
Church, J.P.
Object Type:
Report
System:
The UNT Digital Library
Advanced sequenching technology
This progress report briefly describes the laboratory's advances in chemiluminescent detectors for sequencing DNA, sequence reading algorithm, and for automation of sequencing.(DT)
Date:
January 1, 1992
Creator:
Gesteland, R. F.
Object Type:
Report
System:
The UNT Digital Library