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318,998 Matching Results
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Effects of a spectral modifier on the Clinch River Breeder Reactor low level flux monitor experiments conducted in ZPPR-5
Current design of the Clinch River Breeder Reactor (CRBR) calls for the at-power flux monitors to be located outside the reactor vessel some 330 cm from the center of the core. This design uses these same detectors for the monitoring of refueling operations and the subsequent approach to power. Although adequate for at-power operation, these monitors could prove marginal in the shutdown mode (so called low level flux monitors). A series of experiments are to be performed on the CRBR engineering mockup (ZPPR-5) to test the ex-vessel monitors. The matrix design limits the distance from the core center to the detector position to approximately 200 cm. Hence, the full 330 cm from the core center to the LLFM can not be mocked up in the ZPPR-5 assembly. An attempt was made to design a spectral modifier which would result in the same source and absorber detector response as found in the CRBR design. This was accomplished using the source and adjoint fluxes obtained from a one-dimensional ANISN calculation. The results of examinations of several materials are presented.
Date:
January 1, 1976
Creator:
Selby, D. L.; McAdoo, J. W.; Flanagan, G. F. & Tillett, G. C.
Object Type:
Article
System:
The UNT Digital Library
Probing the Big Bang with LEP
It is shown that LEP probes the Big Bang in two significant ways: (1) nucleosynthesis and (2) dark matter constraints. In the first case, LEP verifies the cosmological standard model prediction on the number of neutrino types, thus strengthening the conclusion that the cosmological baryon density is {approximately}6% of the critical value. In the second case, LEP shows that the remaining non-baryonic cosmological matter must be somewhat more massive and/or more weakly interacting that the favorite non-baryonic dark matter candidates of a few years ago. 59 refs., 4 figs., 2 tabs.
Date:
June 1, 1990
Creator:
Schramm, D. N.
Object Type:
Article
System:
The UNT Digital Library
Recent results in relaxation theory: non-stationary processes and polarization effects
A summary is given of theoretical results concerning line-shape in the presence of non-stationary perturbations, and of the polarization of radiation emitted by a nucleus influenced by time-dependent fields.
Date:
January 1, 1976
Creator:
Blume, M
Object Type:
Article
System:
The UNT Digital Library
High beta and second stability region transport and stability analysis
This report describes ideal and resistive studies of high-beta plasmas and of the second stability region. Emphasis is focused on supershot'' plasmas in TFIR where MHD instabilities are frequently observed and which spoil their confinement properties. Substantial results are described from the analysis of these high beta poloidal plasmas. During these studies, initial pressure and safety factor profiles were obtained from the TRANSP code, which is used extensively to analyze experimental data. Resistive MBD stability studies of supershot equilibria show that finite pressure stabilization of tearing modes is very strong in these high {beta}p plasmas. This has prompted a detailed re-examination of linear tearing mode theory in which we participated in collaboration with Columbia University and General Atomics. This finite pressure effect is shown to be highly sensitive to small scale details of the pressure profile. Even when an ad hoc method of removing this stabilizing mechanism is implemented, however, it is shown that there is only superficial agreement between resistive MBD stability computation and the experimental data. While the mode structures observed experimentally can be found computationally, there is no convincing correlation with the experimental observations when the computed results are compared with a large set of supershot data. …
Date:
September 1, 1992
Creator:
Hughes, M. H.; Phillps, M. W.; Todd, A. M. M.; Krishnaswami, J. & Hartley, R.
Object Type:
Report
System:
The UNT Digital Library
Reactor safety study. An assessment of accident risks in U. S. commercial nuclear power plants. Appendix I. Accident definition and use of event trees. [PWR and BWR]
Information is presented concerning accident definition and use of event trees, event tree methodology, potential accidents covered by the reactor safety study, analysis of potential accidents involving the reactor core, and analysis of potential accidents not involving the core.
Date:
October 1, 1975
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Feasibility study for the computerized automation of the Annapolis Field Office of EPA region III
This report describes a feasibility study for computerized automation of the Annapolis Field Office (AFO) of EPA's Region III. The AFO laboratory provides analytical support for a number of EPA divisions; its primary function at present is analysis of water samples from rivers, estuaries, and the ocean in the Chesapeake Bay area. Automation of the AFO laboratory is found to be not only feasible but also highly desirable. An automation system is proposed which will give major improvements in analytical capacity, quality control, sample management, and reporting capabilities. This system is similar to the LLL-developed automation systems already installed at other EPA laboratories, with modifications specific to the needs of the AFO laboratory and the addition of sample file control. It is estimated that the initial cost of the system, nearly $300,000, would be recouped in about three years by virtue of the increased capacity and efficiency of operation.
Date:
August 1, 1976
Creator:
Ames, H. S.; Barton, G. W. Jr.; Bystroff, R. I.; Crawford, R. W.; Kray, A. M. & Maples, M. D.
Object Type:
Report
System:
The UNT Digital Library
Characterization of SAES St198 zirconium-iron-tin alloy
A waste minimization program to develop a non-oxidative stripper system based on metallic getters is being conducted. Initial development is being performed using a Zr-Fe-Sn intermetallic alloy getter procured as Stl98 from SAES Gefters/USA., Inc. This memorandum describes characterizations of physical and compositional properties of SAES Stl98. SAES Stl98 getter was supplied as very durable, cylindrical pellets made by compaction of. granules of Zr-Fe-Sn alloy up to 150 [mu]m in size. Pellet density was 5.2 g/mL corresponding to 24.8% open porosity and very little closed porosity. Bulk composition of Stl98 was 73.6 weight percent (w/o) Zr, 23.3 w/o Fe and 1.2 w/o Sn. Stl98 consists of Zr[sub 2]Fe primary phase along with four secondary phases (ZrFe[sub 2], Zr[sub 5]FeSn, [alpha]-zirconium, and [eta]-Zr[sub 4]Fe[sub 2]O[sub 0.6]). Hydriding characteristics of Stl98 are expected to differ slightly from those of Zr[sub 2]Fe because [alpha]-zirconium and, possibly, Zr[sub 5]FeSn also react with hydrogen.
Date:
October 13, 1992
Creator:
Mosley, W. C.
Object Type:
Report
System:
The UNT Digital Library
Data base management system (ADBMS) installation guide
This manual provides rough guidelines to aid a programer in installing ADBMS at a computer installation. ADBMS is a set of subroutines which together form a nucleus of a CODASYL-based data base management system. The use of this system is explained in detail in ''ADBMS Users Guide'' by E.W. Berss, Lawrence Livermore Laboratory, Feb. 1977.
Date:
March 17, 1977
Creator:
Birss, E. W.
Object Type:
Report
System:
The UNT Digital Library
Biogeochemistry of trace metals in Chesapeake Bay. Progress report, 1 July 1976--30 June 1977. [Comparison with San Francisco Bay]
Progress is reported on studies on the geochemistry and fate of trace amounts of Fe, Mn, Cu, and Zn in surface waters and sediments of the Susquehanna River and Chesapeake Bay. The path of suspended sediments in Chesapeake Bay and San Francisco Bay were compared.
Date:
January 1, 1977
Creator:
Gross, M. G.; Eaton, A. D. & Grant, V.
Object Type:
Report
System:
The UNT Digital Library
Understanding of carbonate fuel cell resistance issues for performance improvement
The overall objective of the current Task 6 under Contract AC21-90MC27168 is to develop understanding as well as quantification of cell ohmic resistance in carbonate fuel cell. The important resistance-contributing interfaces and elements are being investigated in high-temperature out-of-cell resistance experiments, using an AC-impedance technique. Ohmic resistance loss in a state-of-the-art carbonate fuel cell contributes about 65 mV loss at BOL (beginning-of-life). It may increase to about as much as 145 mV after 40,000 hours. Its reduction will offer further improvement in fuel cell power plant efficiency. The important resistance contributing elements/interfaces are illustrated in Figure 1. The majority of the ohmic loss attributed to electrolyte matrix (ionic) and cathode-side hardware (electronic). The ohmic loss due to anode-side hardware can generally be neglected because the anode-side hardware is surface protected resulting in very little surface oxide formation. The ohmic resistance of the electrodes is also negligible. The matrix ionic resistance is influenced by many factors: electrolyte conductivity, matrix porosity, tortuosity, electrolyte fill level and matrix thickness. At present, matrix contributes to > 300 m{Omega}cm{sup 2} (>70% of the total cell ohmic resistance) and is the major resistance contributor.
Date:
January 1, 1992
Creator:
Yuh, C. Y.; Farooque, M. & Johnsen, R.
Object Type:
Article
System:
The UNT Digital Library
Ion-channeling observation of correlated atomic displacements below Tc in YBa sub 2 Cu sub 3 O sub 7-x and Pb-doped Bi sub 2 Sr sub 2 CaCu sub 2 O sub x
Temperature dependent studies of ion channeling in high-quality, high-Tc single-crystals are summarized. The measurements revealed an abrupt change across Tc in displacements in the a-b plane of the Cu(I and 2) and 0(4) atoms; normal Debye-like'' vibrations were found for the Y and Ba atoms. The anomalous atomic displacements were found for both proton and He channeling, and manifested themselves as an abrupt increase in the critical angle and a simultaneous decrease in the minimum yield. The anomalous change in Cu-0 displacements shifted directly with stoichiometry-induced changes in Tc, implying a causal fink between the observed phonon anomaly and the superconducting state. An apparently identical anomaly was found in (Bi{sub 1.7}Pb{sub 0.3})Sr{sub 2}CaCu{sub 2}O{sub x}, indicating that it is a general feature of high-T, superconductivity. A comparison with other experimental measurements in YBa{sub 2}Cu{sub 3}O{sub 7-x}, including a detailed neutron diffraction study, indicates that the anomaly is not due to an overall reduction in average vibrational amplitude, but arises instead from a strongly correlated sequence of Cu(1 and 2) and 04 displacements that appears with the onset of superconductivity. These strongly correlated displacements are either dynamic, or they are static distortions that fail to preserve the overall crystal symmetry.
Date:
July 1, 1992
Creator:
Rehn, L. E.; Sharma, R. P. & Baldo, P. M.
Object Type:
Article
System:
The UNT Digital Library
National Radiobiology Archives Distributed Access User's Manual, Version 1. 1
This supplement to the NRA Distributed Access User's manual (PNL-7877), November 1991, describes installation and use of Version 1.1 of the software package; this is not a replacement of the previous manual. Version 1.1 of the NRA Distributed Access Package is a maintenance release. It eliminates several bugs, and includes a few new features which are described in this manual. Although the appearance of some menu screens has changed, we are confident that the Version 1.0 User's Manual will provide an adequate introduction to the system. Users who are unfamiliar with Version 1.0 may wish to experiment with that version before moving on to Version 1.1.
Date:
June 1, 1992
Creator:
Smith, S. K.; Prather, J. C.; Ligotke, E. K. & Watson, C. R.
Object Type:
Report
System:
The UNT Digital Library
Integration of Transients in Axisymmetrical Cavities for Accelerators: Formulation and applications to BNL Photocathode Gun
This note provides a sketch of the formalism used for the Integration of Transients in Axisymmetrical Cavities for Accelerators, (ITACA). Application to study the BNL Photocathode Gun via the code ITACA is also included.
Date:
April 1, 1992
Creator:
Parsa, Z. (Brookhaven National Lab., Upton, NY (United States)) & Serafini, L. (Istituto Nazionale di Fisica Nucleare, Milan (Italy) Milan Univ. (Italy))
Object Type:
Report
System:
The UNT Digital Library
Boronization in DIII-D
A thin boron film has been applied to the DIII-D tokamak plasma facing surfaces to reduce impurity influx, particularly oxygen and carbon. A direct result of this surface modification was the observation of a regime of very high energy confinement, VH-mode, with confinement times from 1.5 to 2 times greater than predicted by H-mode scaling relation for the same set of parameters. VH-mode discharges are characterized by low ohmic target densities, low edge neutral pressure, and reduced cycling. These conditions have reduced the collisionality, {nu}*, in the edge region producing a higher edge pressure gradient and a significant bootstrap current, up to 30% of the total current. We will describe the edge plasma properties after boronization including reductions in recycling inferred from measurements of {tau}{sup p}*. In particular we will discuss the edge plasma conditions necessary for access to VH-mode including the boronization process and properties of the deposited film.
Date:
May 1, 1992
Creator:
Jackson, G. L.; Burrell, K. H.; DeBoo, J. C.; Greenfield, C. M.; Groebner, R. J.; Hodapp, T. et al.
Object Type:
Article
System:
The UNT Digital Library
Elastic and plastic deformation of solids. Final report, February 1, 1960--January 31, 1976
This is a summary of the techniques used and the results obtained in the study of creep at high pressure, pressure dependence of yield stress and elastic constants, etc. 58 references. (DLC)
Date:
July 15, 1976
Creator:
Ruoff, A. L.
Object Type:
Report
System:
The UNT Digital Library
Preliminary ''steam tables'' for NaCl solutions. Physical properties of the coexisting phases and thermochemical properties of the H{sub 2}O component. [80{sup 0} to 325{sup 0}C]
Preliminary ''steam tables'' which contain the physical properties of vapor-saturated aqueous sodium chloride solution and the coexisting gas are given for liquid concentrations between 0 mol NaCl/kg H{sub 2{O and halite saturation at temperatures between 80{sup 0} and 325{sup 0}C. For the same conditions, the tables give the partial molal entropy, enthalpy, and volume of H{sub 2}O in the phases. The tables were calculated from parametric equations of state.
Date:
July 1, 1975
Creator:
Haas, J. L. Jr.
Object Type:
Report
System:
The UNT Digital Library
Ultraprecise parabolic interpolator for numerically controlled machine tools. [Digital differential analyzer circuit]
The mathematical basis for an ultraprecise digital differential analyzer circuit for use as a parabolic interpolator on numerically controlled machines has been established, and scaling and other error-reduction techniques have been developed. An exact computer model is included, along with typical results showing tracking to within an accuracy of one part per million.
Date:
February 1, 1977
Creator:
Davenport, C. M.
Object Type:
Report
System:
The UNT Digital Library
ISOCELL trademark proof-of-concept for retrieval of wastes and contaminated soil
ISOCELL{sup TM} cryogenic technology is designed to immobilize buried hazardous, radioactive, and mixed waste and contaminated soil by creating a block of frozen waste and soil that can be safely retrieved, stored, transported, and treated with a minimum of dust or aerosol production. A proof-of-concept'' test of the ISOCELL process was conducted in clean soil by RKK, Ltd., for the Idaho National Engineering Laboratory (INEL). Results indicate ISOCELL technology successfully froze moist soil into a solid block capable of being lifted and retrieved. Test conditions were compared to characteristics of possible buried waste sites in the INEL.
Date:
January 1, 1992
Creator:
Chatwin, T. D. (EG and G Idaho, Inc., Idaho Falls, ID (United States)) & Krieg, R. K. (RKK, Ltd., Bellevue WA (United States))
Object Type:
Article
System:
The UNT Digital Library
Geothermal gas sampling methods
A method for geothermal gas collection for chemical and isotopic gas analysis is described. The CO/sub 2/ and H/sub 2/S are absorbed in a NaOH solution and the residual gas collected in a bottle. The method can be used for sampling gases from hot springs, fumaroles, steam wells, hot water wells, etc. (WHK)
Date:
January 1, 1973
Creator:
Truesdell, A. H. & Pering, K. L.
Object Type:
Report
System:
The UNT Digital Library
Radiative Properties of Ash and Slag
Thermal radiation plays a key role in the operation and efficiency of combustion systems, accounting for over 90% of the heat transfer. The analysis of radiative heat transfer in coal-fired boilers, combustion chambers and other energy systems requires accounting for the effects of inorganic deposits on bounding surfaces and of entrained particulates, such as pulverized coal, char, and fly-ash. These effects can be predicted; however, the accuracy in predicting the radiative properties of entrained pyrolysis (ash) and deposit layers (slag) is limited by inaccurate knowledge of the physical/chemical properties of the materials over a range of material temperatures and radiative wavelengths that is representative of conditions in practical combustion systems. The objective of this project is to make laboratory measurements of the radiative properties of extracted ash and slag deposit samples.
Date:
March 1, 1990
Creator:
Solomon, P. R. & Markham, J. R.
Object Type:
Report
System:
The UNT Digital Library
Pacific Northwest Laboratory quarterly report to ERDA Nuclear Research and Applications Division, January--March 1976. [Use of /sup 90/SrF/sub 2/ and /sup 137/CsCl WESF capsules as heat sources]
Progress in the strontium heat source and beneficial isotopes utilization programs is discussed. The couples required for the long-term tests compatibility were fabricated and the tests are under way. The 1000-hr tests were completed, and examination of the test couples has been started. Compatibility testing of two full-scale WESF /sup 90/SrF/sub 2/ capsules at 800/sup 0/C has started. Additional short-term compatibility testing of 25 potential containment materials are also under way. The 5000-hr aging tests of Hastelloy C-4 were completed and the specimens are being examined. Conceptual flowsheets were drawn up for recovery of various combinations of radioisotopes from stored high level wastes, and rough cost estimates were made. Additional calculations of /sup 137/CsCl capsule irradiation efficiency are reported. Conclusions of a study of the beneficial utilization of WESF /sup 90/SrF/sub 2/ capsules are presented.
Date:
April 1, 1976
Creator:
Fullam, H. T. & Harmon, K. M.
Object Type:
Report
System:
The UNT Digital Library
Carcinogenic aromatic amine field monitoring and workplace decontamination
Methods are described for monitoring work areas for the presence of primary amines and chemicals readily transformable to primary amines that are potentially carcinogenic. Chemical spot tests for surface monitoring are described and their capabilities and limitations are discussed for monitoring work areas, equipment, and respirators after use in hazardous environments. Methods for work area and personnel decontamination are also described. A list of cancer-suspect amines is included. (CH)
Date:
January 1, 1977
Creator:
Weeks, R. W., Jr.; Dean, B. J. & Yasuda, S. K.
Object Type:
Article
System:
The UNT Digital Library
Product from variability in the mechanical behavior of type 304 stainless steel at room temperature and 593/sup 0/C (1100/sup 0/F)
Data are presented that describe the variability of 15 products of a reference heat of type 304 stainless steel tested in the laboratory reannealed condition: chemistry hardness, grain size, yield strength at room temperature, tensile curves at 593/sup 0/C (1100/sup 0/F), and creep-rupture curves to 1000 h at 593/sup 0/C (1100/sup 0/F). The standard deviation, representing the variation in the yield strength of the 15 products about the average, is near+-l.7 MPa at room temperature and +-6.3 MPa at 593/sup 0/C (1100/sup 0/F). The 1000-h rupture strength varies by 2.5 percent (approximately +-6.2 MPa) from the average and the stress to produce a minimum creep rate of 0.01 percent/h by 3.0 percent (approximately +-5.0 MPa). Variation of strength in the primary creep range is also examined. It is observed that the 25-mm plate is fairly representative of the product average. Reasons for variability are examined: carbon content, nitrogen content, grain size, temperature control, and extensometer performance. 7 tables, 5 figures.
Date:
January 1, 1976
Creator:
Swindeman, R. W.; McAffee, W. J. & Sikka, V. K.
Object Type:
Article
System:
The UNT Digital Library
Design and analysis of multicavity prestressed concrete reactor vessels. [HTGR]
During the past 25 years, a rather rapid evolution has taken place in the design and use of prestressed concrete reactor vessels (PCRVs). Initially the concrete vessel served as a one-to-one replacement for its steel counterpart. This was followed by the development of the integral design which led eventually to the more recent multicavity vessel concept. Although this evolution has seen problems in construction and operation, a state-of-the-art review which was recently conducted by the Oak Ridge National Laboratory indicated that the PCRV has proven to be a satisfactory and inherently safe type of vessel for containment of gas-cooled reactors from a purely functional standpoint. However, functionalism is not the only consideration in a demanding and highly competitive industry. A summary is presented of the important considerations in the design and analysis of multicavity PCRVs together with overall conclusions concerning the state of the art of these vessels.
Date:
January 1, 1977
Creator:
Goodpasture, D. W.; Burdette, E. G. & Callahan, J. P.
Object Type:
Article
System:
The UNT Digital Library