Effects of catalytic mineral matter on CO/CO sub 2 , temperature and burning time for char combustion (open access)

Effects of catalytic mineral matter on CO/CO sub 2 , temperature and burning time for char combustion

The temperature of a char particle burning in an oxygen containing atmosphere is the product of a strongly coupled balance between particle size and physical properties, heat transfer from the particle, surface reactivity, CO/CO{sub 2} ratio and gas phase diffusion in the surrounding boundary layer and within the particle. CO{sub 2}/CO ratios can be strongly influenced by catalytic material in the carbon and by the char temperature. In this program we are measuring the CO{sub 2}/CO ratio for both catalyzed and uncatalyzed chars over a wide range of temperature. These results will then be used to develop predictive models for char temperature and burning rates. The electrodynamic balance has been successfully used to make such measurements for single 200{mu}m spherocarb particles. A few theoretical approaches to model a single particle oxidation have been made, but most of them assumed the infinitely thin reaction zone at the particle surface. This approach can not explain pore diffusion limitation, structural change, or reaction at low temperatures inside the particle. Too simplifying solid phase reaction may leads to wrong predictions. In this report, progress on constructing models including both solid and gas phase reaction are reported.
Date: May 4, 1992
Creator: Longwell, J. P.; Sarofim, A. F.; Lee, Chun-Hyuk & Modestino, A. J.
Object Type: Report
System: The UNT Digital Library
NQR-NMR studies of higher alcohol synthesis Cu-Co catalysts (open access)

NQR-NMR studies of higher alcohol synthesis Cu-Co catalysts

During this period, we focused our attention in analyzing the magnetic nature of the extensively used trimetallic catalyst system Cu-Co-Cr for the production of higher alcohols. We believe that there could be some correspondence between the catalytic and magnetic behaviors of the transition metal catalyst systems. Both the morphology and metallic charge distribution of the particles are known to govern the catalytic as well as the magnetic properties of the system.
Date: May 4, 1992
Creator: Murty, A.N.
Object Type: Report
System: The UNT Digital Library
Intelligent optical design program (open access)

Intelligent optical design program

Described is a general approach to the development of computer programs capable of designing image-forming optical systems without human intervention and of improving their performance with repeated attempts. The approach utilizes two ideas: (1) interpretation of technical design as a mapping in the configuration space of technical characteristics and (2) development of an intelligent routine that recognizes global optima. Examples of lens systems designed and used in the development of the general approach are presented, current status of the project is summarized, and plans for the future efforts are indicated.
Date: May 4, 1984
Creator: Bohachevsky, I.O.; Viswanathan, V.K. & Woodfin, G.
Object Type: Article
System: The UNT Digital Library
Powerplant Productivity Improvement Study: historic performance of Illinois investor-owned electrical-generating units. Final report, Project 2, Task 1 (open access)

Powerplant Productivity Improvement Study: historic performance of Illinois investor-owned electrical-generating units. Final report, Project 2, Task 1

In this task the historical performance of powerplants in Illinois was examined and the opportunities for improved powerplant productivity in Illinois was determined. The four utilities considered were the major investor-owned electric generating utilities in Illinois, i.e., Central Illinois Light Co., (CILCO), Central Illinois Public Service (CIPS), Commonwealth Edison (CECO), and Illinois Power (IP). The major findings are: (1) for evaluation purposes, the equivalent availability was judged to be the most-appropriate measure; (2) in terms of powerplant productivity, IP is among the best in the nation and, in terms of productivity from large coal units, it ranks in the top five nationally; (3) in general, the performance of coal-fired units of CILCO and CECO have been below national averages and in some cases, significantly below; (4) a review of the trends in production of all Illinois units reveals that Illinois units as a group have been generally below national averages for the respective unit classes; (5) as noted in this and other studies, productivities of the nuclear plants in Illinois have been below the national average for all comparable nuclear plants; and (6) this analysis should be updated when national 1977 and 1978 Edison Electric Institute data become publicly available.
Date: May 4, 1979
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Responsibilities, opportunities and challenges in geophysical exploration (open access)

Responsibilities, opportunities and challenges in geophysical exploration

Geophysical exploration for engineering purposes is conducted to decrease the risk in encountering site uncertainties in construction of underground facilities. Current responsibilities, opportunities and challenges for those with geophysical expertise are defined. These include: replacing the squiggly line format, developing verification sites for method evaluations, applying knowledge engineering and assuming responsibility for crucial national problems involving rock mechanics expertise.
Date: May 4, 1982
Creator: Rytle, R. J.
Object Type: Article
System: The UNT Digital Library
Laser heating of solid matter by light pressure-driven shocks (open access)

Laser heating of solid matter by light pressure-driven shocks

Heating by irradiation of a solid surface in vacuum with 5 x 10{sup 20} W cm{sup -2}, 0.8 ps, 1.05 {micro}m wavelength laser light is studied by x-ray spectroscopy of the K-shell emission from thin layers of Ni, Mo and V. A surface layer is heated to {approx} 5 keV with an axial temperature gradient of 0.6 {micro}m scale length. Images of Ni Ly{sub {alpha}} show the hot region has a {approx} 25 {micro}m diameter, much smaller than {approx} 70 {micro}m region of K{sub {alpha}} emission. 2D particle-in-cell (PIC) simulations suggest that the surface heating is due to a light pressure driven shock.
Date: May 4, 2007
Creator: Akli, K.; Hansen, S. B.; Kemp, A. J.; Freeman, R. R.; Beg, F. N.; Clark, D. et al.
Object Type: Article
System: The UNT Digital Library
Innovative Electromagnetic Sensors for Pipeline Crawlers Progress Report: October 2005 - March 2006 (open access)

Innovative Electromagnetic Sensors for Pipeline Crawlers Progress Report: October 2005 - March 2006

Internal inspection of pipelines is an important tool for ensuring safe and reliable delivery of fossil energy products. Current inspection systems that are propelled through the pipeline by the product flow cannot be used to inspect all pipelines because of the various physical barriers they encounter. Recent development efforts include a new generation of powered inspection platforms that crawl slowly inside a pipeline and are able to maneuver past the physical barriers that can limit inspection. At Battelle, innovative electromagnetic sensors are being designed and tested for these new pipeline crawlers. The various sensor types can be used to assess a wide range of pipeline anomalies including corrosion, mechanical damage, and cracks. Battelle is in the final year on a projected three-year development effort. In the first year, two innovative electromagnetic inspection technologies were designed and tested. Both were based on moving high-strength permanent magnets to generate inspection energy. One system involved translating permanent magnets towards the pipe. A pulse of electric current would be induced in the pipe to oppose the magnetization according to Lenz's Law. The decay of this pulse would indicate the presence of defects in the pipe wall. This inspection method is similar to pulsed eddy …
Date: May 4, 2006
Creator: Nestleroth, J. Bruce
Object Type: Report
System: The UNT Digital Library
LSST Detector Module and Raft Assembly Metrology Concepts (open access)

LSST Detector Module and Raft Assembly Metrology Concepts

None
Date: May 4, 2006
Creator: Takacs, P. Z.; O'Connor, P.; Radeka, V.; Mahler, G.; Frank. J. & Geary, J.
Object Type: Article
System: The UNT Digital Library
MECHANICAL RESPONSE OF STITCHED T300 MAT/URETHANE 420 IMR COMPOSITE LAMINATES: PROPERTY/ORIENTATION DEPENDENCE AND DAMAGE EVOLUTION (open access)

MECHANICAL RESPONSE OF STITCHED T300 MAT/URETHANE 420 IMR COMPOSITE LAMINATES: PROPERTY/ORIENTATION DEPENDENCE AND DAMAGE EVOLUTION

None
Date: May 4, 2000
Creator: Deng, S.
Object Type: Report
System: The UNT Digital Library
Study of the $\tau^- to 3h^- 2h^+ \nu_\tau$ Decay (open access)

Study of the $\tau^- to 3h^- 2h^+ \nu_\tau$ Decay

The branching fraction of the {tau}{sup -} {yields} 3h{sup -} 2h{sup +} {nu}{sub {tau}} decay (h = {pi}, K) is measured with the BABAR detector to be (8.56 {+-} 0.05 {+-} 0.42) x 10{sup -4}, where the first error is statistical and the second systematic. The observed structure of this decay is significantly different from the phase space prediction, with the {rho} resonance playing a strong role. The decay {tau}{sup -} {yields} f{sub 1}(1285){pi}{sup -}{nu}{sub {tau}}, with the f{sub 1}(1285) meson decaying to four charged pions, is observed and the branching fraction is measured to be (3.9 {+-} 0.7 {+-} 0.5) x 10{sup -4}.
Date: May 4, 2005
Creator: Aubert, Bernard; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
Object Type: Article
System: The UNT Digital Library
Overview of Beam Instrumentation and Diagnostics for the NSLS-II Project (open access)

Overview of Beam Instrumentation and Diagnostics for the NSLS-II Project

A new, ultra-bright 3rd generation light source, the NSLS-II Project, is planned to be built at Brookhaven National Laboratory. The light source being developed will have unprecedently small beam horizontal emittance and will provide the radiation sources with a brightness of 3 x 10{sup 21} photons/sec/0.1%BW/mm{sup 2}/mrad{sup 2}. In this paper we present the detailed specifications and a comprehensive description of the planned beam instrumentation system and the first results of the ongoing instrumentation R&D activities on beyond state-of-the-art subsystems.
Date: May 4, 2008
Creator: Singh,O.
Object Type: Article
System: The UNT Digital Library
Remaining Sites Verification Package for the 126-F-2, 183-F Clearwells, Waste Site Reclassification Form 2006-017 (open access)

Remaining Sites Verification Package for the 126-F-2, 183-F Clearwells, Waste Site Reclassification Form 2006-017

The 126-F-2 site is the clearwell facility formerly used as part of the reactor cooling water treatment at the 183-F facility. During demolition operations in the 1970s, potentially contaminated debris was disposed in the eastern clearwell structure. The site has been remediated by removing all debris in the clearwell structure to the Environmental Restoration Disposal Facility. The results of radiological surveys and visual inspection of the remediated clearwell structure show neither residual contamination nor the potential for contaminant migration beyond the clearwell boundaries. The results of verification sampling at the remediation waste staging area demonstrated that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also showed that residual contaminant concentrations are protective of groundwater and the Columbia River.
Date: May 4, 2006
Creator: Carlson, R. A.
Object Type: Report
System: The UNT Digital Library
Reconstruction of Sedimentary Rock Based on MechanicalProperties (open access)

Reconstruction of Sedimentary Rock Based on MechanicalProperties

We describe a general, physics-based approach to numericalreconstruction of the geometrical structure and mechanical properties ofnatural sedimentary rock in 3D. Our procedure consists of three mainsteps: sedimentation, compaction, and diagenesis, followed by theverification of rock mechanical properties. The dynamic geologicprocesses of grain sedimentation and compaction are simulated by solvinga dimensionless form of Newton's equations of motion for an ensemble ofgrains. The diagenetic rock transformation is modeled using a cementationalgorithm, which accounts for the effect of rock grain size on therelative rate of cement overgrowth. Our emphasis is on unconsolidatedsand and sandstone. The main input parameters are the grain sizedistribution, the final rock porosity, the type and amount of cement andclay minerals, and grain mechanical properties: the inter-grain frictioncoefficient, the cement strength, and the grain stiffness moduli. We usea simulated 2D Fontainebleau sandstone to obtain the grain mechanicalproperties. This Fontainebleau sandstone is also used to study theinitiation, growth, and coalescence of micro-cracks under increasingvertical stress. The box fractal dimension of the micro-crackdistribution, and its variation with the applied stress areestimated.
Date: May 4, 2004
Creator: Jin, Guodong; Patzek, Tad W. & Silin, Dmitry B.
Object Type: Report
System: The UNT Digital Library
ALDEHYDE AND OTHER VOLATILE ORGANIC CHEMICAL EMISSIONS IN FOUR FEMA TEMPORARY HOUSING UNITS ? FINAL REPORT (open access)

ALDEHYDE AND OTHER VOLATILE ORGANIC CHEMICAL EMISSIONS IN FOUR FEMA TEMPORARY HOUSING UNITS ? FINAL REPORT

Four unoccupied FEMA temporary housing units (THUs) were studied to assess their indoor emissions of volatile organic compounds including formaldehyde. Measurement of whole-THU VOC and aldehyde emission factors (mu g h-1 per m2 of floor area) for each of the four THUs were made at FEMA's Purvis MS staging yard using a mass balance approach. Measurements were made in the morning, and again in the afternoon in each THU. Steady-state indoor formaldehyde concentrations ranged from 378 mu g m-3 (0.31ppm) to 632 mu g m-3 (0.52 ppm) in the AM, and from 433 mu g m-3 (0.35 ppm) to 926 mu g m-3 (0.78 ppm) in the PM. THU air exchange rates ranged from 0.15 h-1 to 0.39 h-1. A total of 45 small (approximately 0.025 m2) samples of surface material, 16 types, were collected directly from the four THUs and shipped to Lawrence Berkeley Laboratory. The material samples were analyzed for VOC and aldehyde emissions in small stainless steel chambers using a standard, accurate mass balance method. Quantification of VOCs was done via gas chromatography -- mass spectrometry and low molecular weight aldehydes via high performance liquid chromatography. Material specific emission factors (mu g h-1 per m2 of material) …
Date: May 4, 2008
Creator: Salazar, Olivia; Maddalena, Randy L.; Russell, Marion; Sullivan, Douglas P. & Apte, Michael G.
Object Type: Report
System: The UNT Digital Library
Evaluation of Pinhole Camera Resolution for NSLS-II Storage Ring (open access)

Evaluation of Pinhole Camera Resolution for NSLS-II Storage Ring

The NSLS-II Storage Ring provides ultrabright radiation sources with extra-small sizes of the circulating electron beam. The beam dimensions will be monitored with a pinhole camera. In this paper they discuss the possible design and ultimate achievable resolution of the system. Modeling is based on the SRW code as well as numerical calculations using MATLAB.
Date: May 4, 2008
Creator: Pinayev,I.
Object Type: Article
System: The UNT Digital Library
Topological Strings And (Almost) Modular Forms (open access)

Topological Strings And (Almost) Modular Forms

The B-model topological string theory on a Calabi-Yau threefold X has a symmetry group {Lambda}, generated by monodromies of the periods of X. This acts on the topological string wave function in a natural way, governed by the quantum mechanics of the phase space H{sup 3}(X). We show that, depending on the choice of polarization, the genus g topological string amplitude is either a holomorphic quasi-modular form or an almost holomorphic modular form of weight 0 under {Lambda}. Moreover, at each genus, certain combinations of genus g amplitudes are both modular and holomorphic. We illustrate this for the local Calabi-Yau manifolds giving rise to Seiberg-Witten gauge theories in four dimensions and local IP{sub 2} and IP{sub 1} x IP{sub 1}. As a byproduct, we also obtain a simple way of relating the topological string amplitudes near different points in the moduli space, which we use to give predictions for Gromov-Witten invariants of the orbifold C{sub 3}/ZZ{sub 3}.
Date: May 4, 2007
Creator: Aganagic, Mina; Bouchard, Vincent & Klemm, Albrecht
Object Type: Article
System: The UNT Digital Library
Two-dimensional magnetohydrodynamic calculations for a 5 MJ plasma focus (open access)

Two-dimensional magnetohydrodynamic calculations for a 5 MJ plasma focus

The performance of a 5 MJ plasma focus is calculated using our two-dimensional magnetohydrodynamic (2-D MHD) code. Two configurations are discussed, a solid and a hollow anode. In the case of the hollow anode, we find an instability in the current sheath which has the characteristics of the short wave length sausage instability. As the current sheath reaches the axis, the numerical solution is seen to break down. Just before this time, plasma parameters take on the characteristic values rho/rho/sub 0/ = 143, kT/sup i/ = 7.4 keV, B/sub theta/ = 4.7 MG, and V/sub z/ = 60 cm/..mu..s for a zone with r = 0.2 mm. When the numerical solution breaks down, the code shows a splitting of the current sheath (from the axis to the anode) and the loss of a large amount of magnetic energy. Current-sheath stagnation is observed in the hollow anode configuration, also.
Date: May 4, 1979
Creator: Maxon, S.
Object Type: Article
System: The UNT Digital Library
Spontaneous fission of /sup 259/Md (open access)

Spontaneous fission of /sup 259/Md

The mass and kinetic energy distributions of fission fragments from the spontaneous fission of th newly discovered nuclide /sup 259/Md were obtained. /sup 259/Md was identified as the E. C. daughter of /sup 259/No, and was found to decay entirely (> 95%) by spontaneous fission with a 95-min half-life. From the kinetic energies measured for 397 pairs of coincident fragments, a mass distribution was derived that is symmetric with sigma = 13 amu. /sup 259/Md, together with /sup 258/Fm and /sup 259/Fm, form a select group of three nuclides whose mass division in spontaneous fission is highly symmetric. Unlike the total-kinetic-energy (TKE) distributions of /sup 258/Fm and /sup 259/Fm, which peak at approx. = to 240 MeV, this distribution for /sup 259/Md is broad and is 50 MeV lower in energy. Analysis of the mass and energy distributions shows that events near mass symmetry also exhibit a broad TKE distribution, with one-third of the symmetric events having TKEs less than 200 MeV. The associated of low TKEs with symmetric mass division in the fission of very heavy actinides is anomalous and inconsistent with theories based upon the emergence of fragment shells near the scission point. Either three-body fragmentation or peculiar …
Date: May 4, 1979
Creator: Hulet, E. K.; Wild, J. F.; Lougheed, R. W.; Baisden, P. A.; Landrum, J. H.; Dougan, R. J. et al.
Object Type: Article
System: The UNT Digital Library
FFTF materials of construction and surveillance plans (open access)

FFTF materials of construction and surveillance plans

None
Date: May 4, 1979
Creator: Shober, F. R.
Object Type: Report
System: The UNT Digital Library
Design charts for spacing of vacuum line supports (open access)

Design charts for spacing of vacuum line supports

This paper presents design tables and graphs to aid engineers and designers in the selection of support spacing for vacuum beam lines and other vacuum pipes. This data applies to support spacing for thin wall pipes and tubes under an internal vacuum (or open to atmosphere) and subject to external atmospheric pressure. Data is generated from the equations for a simply supported thin walled pipe or tube of circular cross section. These tables and graphs indicate what the minimum spacing of supports is for a pipe or tube of a given radius and supply data for carbon steel, stainless steel, aluminum and copper materials. The wall thickness of the pipe and tube is limited to 1/10 of the pipe radium (T << R/10). A thickness of R/10 results in a decrease in the length values in the attached tables of 10%, whereas a thickness of R/100 results in a decrease in the length values in the attached tables of 1%. Snow loads, wind loads, equipment loads, etc. are not included in the tables and graphs. This data is applicable for vacuum pipes or tubes under its own static deed weight.
Date: May 4, 1987
Creator: Western, J.L. & Krempetz, K.J.
Object Type: Report
System: The UNT Digital Library
Linear analysis of the momentum cooling Fokker-Planck equation (open access)

Linear analysis of the momentum cooling Fokker-Planck equation

In order to optimize the extraction scheme used to take antiprotons out of the accumulator, it is necessary to understand the basic processes involved. At present, six antiproton bunches per Tevatron store are removed sequentially by RF unstacking from the accumulator. The phase space dynamics of this process, with its accompanying phase displacement deceleration and phase space dilution of portions of the stack, can be modelled by numerical solution of the longitudinal equations of motion for a large number of particles. We have employed the tracking code ESME for this purpose. In between RF extractions, however, the stochastic cooling system is turned on for a short time, and we must take into account the effect of momentum stochastic cooling on the antiproton energy spectrum. This process is described by the Fokker-Planck equation, which models the evolution of the antiproton stack energy distribution by accounting for the cooling through an applied coherent drag force and the competing heating of the stack due to diffusion, which can arise from intra-beam scattering, amplifier noise and coherent (Schottky) effects. In this note we examine the aspects of the Fokker-Planck in the regime where the nonlinear terms due to Schottky effects are small. This discussion …
Date: May 4, 1989
Creator: Rosenzweig, J.B.
Object Type: Report
System: The UNT Digital Library
Lessons from the past and prospects for the future (open access)

Lessons from the past and prospects for the future

The author presents his impressions of the conference - that is - major lessons as presented in the talks on nonlinearities and their role in condensed matter physics. (WRF)
Date: May 4, 1986
Creator: Baym, G.
Object Type: Article
System: The UNT Digital Library
Jet stability in the lithium fall reactor (open access)

Jet stability in the lithium fall reactor

A preliminary analysis has been made of the various hydrodynamic aspects involved in the stability of a liquid-lithium jet in a laser-fusion reactor, which comprises a part of LLL's laser fusion power-generation concept. Various physical factors that may affect the jet breakup are delineated, and some approximate calculations are performed to determine their relative influences. Areas of uncertainty are pointed out, along with plans for experimental verification or further theoretical analysis.
Date: May 4, 1978
Creator: Kang, S.W.
Object Type: Article
System: The UNT Digital Library
Radiation-to-light converters for nuclear environments: near-infrared emitters (open access)

Radiation-to-light converters for nuclear environments: near-infrared emitters

The use of fiber optics in the diagnosis of hostile nuclear environments has brought about a pressing need for the development of suitable radiation-to-light converters. These converters must meet stringent diagnostic requirements of linearity and time response while having a wavelength of emission that is compatible with transmission over relatively long lengths of optical fibers. Initial investigations of two, near-infrared-emitting semiconducting materials - CdTe and GaAs are described. Data are presented on the wavelength of emission, linearity, time response, and relative efficiency of these semiconductors. Most data were taken at 77 K because of a dramatic increase in efficiency at this temperature. Measurments show that the intensity-vs-dose curves are linear over several decades of useful input levels. Measurements indicate that GaAs has an efficiency and time response that promise to be useful in diagnostic systems.
Date: May 4, 1981
Creator: Roeske, F.; Rotter, M. D.; Calavan, P. M. & Lutz, S. S.
Object Type: Article
System: The UNT Digital Library