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Review of state-of-the-art of solar collector corrosion processes. Task 1 of solar collector studies for solar heating and cooling applications. Final technical progress report
The state-of-the-art of solar collector corrosion processes is reviewed, and Task 1 of a current research program on use of aqueous heat transfer fluids for solar heating and cooling is summarized. The review of available published literature has indicated that lack of quantitative information exists relative to collector corrosion at the present time, particularly for the higher temperature applications of solar heating and cooling compared to domestic water heating. Solar collector systems are reviewed from the corrosion/service life viewpoint, with emphasis on various applications, collector design, heat transfer fluids, and freeze protection methods. Available information (mostly qualitative) on collector corrosion technology is reviewed to indicate potential corrosion problem areas and corrosion prevention practices. Sources of limited quantitative data that are reviewed are current solar applications, research programs on collector corrosion, and pertinent experience in related applications of automotive cooling and non-solar heating and cooling. A data bank was developed to catalog corrosion information. Appendix A of this report is a bibliography of the data bank, with abstracts reproduced from presently available literature accessions (about 220). This report is presented as a descriptive summary of information that is contained in the data bank.
Date:
April 11, 1980
Creator:
Clifford, J E & Diegle, R B
Object Type:
Report
System:
The UNT Digital Library
Mirror fusion. Quarterly report, April-June 1981
The information in each Quarterly is presented in the same sequence as in the Field Work Package Proposal and Authorization System (WPAS) submissions prepared for the U.S. Department of Energy; the main sections are Applied Plasma Physics, Confinement Systems, Development and Technology, and Mirror Fusion Test Facility (Planning and Projects). On occasion, we shall include information pertaining to the LLNL role as Lead Laboratory for the Open Systems Mirror Fusion Program. Each of these sections is introduced by an overall statement of the goals and purposes of the groups reporting in it. As appropriate within each section, statements of the goals of individual programs and projects are followed by articles containing summaries of significant recent activity and descriptive text.
Date:
September 11, 1981
Creator:
unknown
Object Type:
Article
System:
The UNT Digital Library
Method of forming metallic coatings on polymeric substrates and of forming graded polymeric coatings or films
The invention described herein relates to methods of forming graded polymeric coatings or films on a desired substrate and of forming metallic coatings on polymeric or other nonmetallic substrates. In particular, it relates to methods of forming such coatings or films by sorption and/or diffusion of metals into coatings or films of polymeric material deposited by conventional techniques on a desired substrate.
Date:
March 11, 1981
Creator:
Liepins, R.
Object Type:
Patent
System:
The UNT Digital Library
(Performance evaluation of fabric bag filters on a bench-scale coal gasifier)
The objective of the proposed work is to demonstrate the operational and economic feasibility of using high-temperature ceramic filters for particulate control in a variety of coal gasification power generating systems.
Date:
October 11, 1985
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Multi-temperature gas chromatography using isothermal columns in series. Technical report
A computer-controlled three-oven gas chromatograph having a multi-position stream-switching valve has been used first to divide a wide-boiling mixture of n-alkanes into three cuts and then to fractionate each cut using a packed column at a different temperature. After initial injection of the sample into the highest temperature column, the low boilers were switched to a low temperature oven. Then, the mid-boilers were switched to a column at an intermediate temperature. For routine repetitive analyses, the multi-oven approach offers an attractive alternative.
Date:
August 11, 1980
Creator:
Spencer, W. A. & Rogers, L. B.
Object Type:
Report
System:
The UNT Digital Library
Thyratron characteristics under high di/dt and high-repetition-rate operation
Power conditioning systems for high peak and average power, high repetition rate discharge excited lasers involve operation of modulator components in unconventional regimes. Reliable operation of switches and energy storage elements under high voltage and high di/dt conditions is a pacing item for laser development at the present time. To test and evaluate these components a Modulator Component Test Facility (MCTF) was constructed. The MCTF consists of a command charge system, energy storage capacitors, thyratron switch with inverse thyratron protection, and a resistive load. The modulator has initially been operated at voltages up to 60 kV at 600 Hz. Voltage, current, and calorimetric diagnostics are provided for major modulator components. Measurements of thyratron characteristics under high di/dt operation are presented. Commutation energy loss and di/dt have been measured as functions of the tube hydrogen pressure.
Date:
May 11, 1981
Creator:
Ball, D.; Hill, J. & Kan, T.
Object Type:
Article
System:
The UNT Digital Library
Symplectic numerical integration of Hamiltonian systems
This paper describes some general techniques available for symplectic or Lie-Poisson integration and illustrate the results with some numerical computations. In this spirit, I also discuss reversible integration, equivariant integration, integration of volume preserving flows, and symplectic cellular automata. My intention is not to be exhaustive but to give a representative review. 76 refs., 5 figs.
Date:
September 11, 1989
Creator:
Scovel, C.
Object Type:
Article
System:
The UNT Digital Library
Heating by the Raman instability
Computer simulations are presented of the reflection and heating due to stimulated Raman backscatter of intense laser light in large regions of underdense plasma. The heated electron distribution is found to be approximately a Maxwellian of temperature (m/sub e//2)v/sub p//sup 2/, where v/sub p/ is the phase velocity of the electron plasma wave. A simple model of the reflection is presented. Raman may cause a pre-heat problem with large laser fusion reactor targets.
Date:
April 11, 1980
Creator:
Estabrook, K.G. & Kruer, W.L.
Object Type:
Article
System:
The UNT Digital Library
Safety assessment document for the Dynamic Test Complex B854
A safety assessment was performed to determine if potential accidents at the 854 Complex at Site 300 could present undue hazards to the general public, personnel at Site 300, or have an adverse effect on the environment. The credible accidents that might have an effect on these facilities or have off-site consequences were considered. These were earthquake, extreme wind (including missiles), lightning, flood, criticality, high explosive (HE) detonation that disperses uranium and beryllium, spontaneous oxidation of plutonium, explosions due to finely divided particles, and a fire. Seismic and extreme wind (including missiles) analyses indicate that the buildings are basically sound. The lightning protection system is in the process of being upgraded to meet AMCR 385-100. These buildings are located high above the dry creek bed so that a flood is improbable. The probability of high explosive detonation involving plutonium is very remote since the radioactive materials are encased and plutonium and HE are not permitted concurrently in the same area at Site 300. (The exception to this policy is that explosive actuating devices are sometimes located in assemblies containing fissile materials. However, an accidental actuation will not affect the safe containment of the plutonium within the assembly.) There is a …
Date:
December 11, 1981
Creator:
Odell, B.N. & Pfeifer, H.E.
Object Type:
Report
System:
The UNT Digital Library
Laser-damage thresholds of thin-film optical coatings at 248 nm
We have measured the laser-induced damage thresholds for 248 nm wavelength light of over 100 optical coatings from commercial vendors and research institutions. All samples were irradiated once per damage site with temporally multi-lobed, 20-ns pulses generated by a KrF laser. The survey included high, partial, and dichroic reflectors, anti-reflective coatings, and single layer films. The samples were supplied by ten vendors. The majority of samples tested were high reflectors and antireflective coatings. The highest damage thresholds were 8.5 to 9.4 J/cm/sup 2/, respectively. Although these represent extremes of what has been tested so far, several vendors have produced coatings of both types with thresholds which consistently exceed 6 J/cm/sup 2/. Repeated irradiations of some sites were made on a few samples. These yielded no degradation in threshold, but in fact some improvement in damage resistance. These same samples also exhibited no change in threshold after being retested seven months later.
Date:
December 11, 1981
Creator:
Milam, D.; Rainer, F. & Lowdermilk, W.H.
Object Type:
Article
System:
The UNT Digital Library
Low-exposure tritium radiotoxicity in mammals
Studies of tritium radiotoxicity involving chronic /sup 3/H0H exposures in mammals demonstrate in both mice and monkeys that biological effects can be measured following remarkably low levels of exposure - levels in the range of serious practical interest to radiation protection. These studies demonstrate also that deleterious effects of /sup 3/H beta radiation do not differ significantly from those of gamma radiation at high exposures. In contrast, however, at low exposures tritium is significantly more effective than gamma rays, rad for rad, by a factor approaching 3. This is important for hazard evaluation and radiation protection because knowledge concerning biological effects of chronic low-level radiation exposure has come mainly from gamma-ray data; and predictions based on gamma-ray data will underestimate tritium effects - especially at low exposures - unless the RBE is fully taken into account.
Date:
February 11, 1982
Creator:
Dobson, R.L.
Object Type:
Article
System:
The UNT Digital Library
Study of corrosion in multimetallic systems. Task 2 of solar collector studies for solar heating and cooling applications. Final technical progress report
Corrosion measurements were made on candidate alloys of construction for non-concentrating solar collectors under simulated conditions of collector operation. Materials evaluated were aluminum alloys 1100, 3003, and 6061, copper alloy 122, Type 444 stainless steel, and 1018 plain carbon steel. The solutions used were equivolume mixtures of ethylene glycol and water, and propylene glycol and water. They were used without corrosion inhibitors but with addition of chloride, sulfate, and bicarbonate ions. The influences of dissolved oxygen, solution flow velocity, and heat transfer were evaluated. Corrosion morphologies investigated were general attack, pitting, crevice corrosion, and galvanic corrosion. Experimental results indicated that aluminum alloys can experience severe pitting and crevice corrosion at chloride concentrations approaching 50 ppM. The corrosion rate of copper exceeded about 100 ..mu..m/yr in ethylene glycol solutions and about 80 ..mu..m/yr in propylene glycol solutions. Crevice corrosion was not observed for copper, but severe galvanic corrosion occurred when it was coupled to T444 stainless steel. T444 steel corroded at rates of less than 1 ..mu..m/yr under all exposure conditions. During circulation at 100 C in the presence of air, ethylene glycol solutions acidified because of degradation of the glycol. The initial pH of propylene glycol solutions was already low, …
Date:
April 11, 1980
Creator:
Diegle, R B
Object Type:
Report
System:
The UNT Digital Library
Dipole aperture and superconductor requirements
The cost of an accelerator is not proportional to the aperture. A change in aperture by a certain percentage results in an overall accelerator cost change by only a fraction of that percentage; the fraction may be between 0.1 and 0.5 and is almost independent of the bending field. This estimate is obtained by analyzing the superconductor requirements as a function of aperture and by making rough estimates of the largest cost items of the accelerator such as magnets and ring tunnel.
Date:
December 11, 1983
Creator:
Wipf, S.L.
Object Type:
Article
System:
The UNT Digital Library
Writing Parallel, Discrete-Event Simulations in Modsim: Insight and Experience
The Time Warp Operating System (TWOS) has been the focus of much research in parallel simulation. A new language, called ModSim, has been developed for use in conjunction with TWOS. The coupling of ModSim and TWOS provides a tool to construct large, complex simulation models that will run on several parallel and distributed computer systems. As part of the Griffin Project'' underway here at Los Alamos National Laboratory, there is strong interest in assessing the coupling of ModSim and TWOS from an application-oriented perspective. To this end, a key component of the Eagle combat simulation has been implemented in ModSim for execution on TWOS. In this paper brief overviews of ModSim and TWOS will be presented. Finally, the compatibility of the computational models presented by the language and the operating system will be examined in light of experience gained to date. 18 refs., 4 figs.
Date:
September 11, 1989
Creator:
Rich, D.O. & Michelsen, R.E.
Object Type:
Article
System:
The UNT Digital Library
Nitrogen fixation method and apparatus. [DOE patent application]
A method and apparatus for achieving nitrogen fixation includes a volumetric electric discharge chamber. The volumetric discharge chamber provides an even distribution of an electron beam, and enables the chamber to be maintained at a controlled energy to pressure (E/p) ratio. An E/p ratio of from 5 to 15 kV/atm of O/sub 2//cm promotes the formation of vibrationally excited N/sub 2/. Atomic oxygen interacts with vibrationally excited N/sub 2/ at a much quicker rate than unexcited N/sub 2/, greatly improving the rate at which NO is formed.
Date:
August 11, 1981
Creator:
Chen, H. L.
Object Type:
Patent
System:
The UNT Digital Library
Underground muon observations in the Soudan 2 detector
The Soudan 2 nucleon decay detector has recorded data since Summer 1988 using a quarter (dimensions 4 m by 8 m by 5 m high) of the eventual detector. This iron-argon time projection chamber records extensive data on each event and has excellent angular and multi-track resolution. We describe the trigger, the event analysis procedure and the current status of the detector and the underground muon data sample. 1 ref.
Date:
September 11, 1989
Creator:
Allison, W. W. M.; Barr, G. D.; Brooks, C. B.; Cobb, J. H.; Kirby-Gallagher, L. M.; Giles, R. H. et al.
Object Type:
Article
System:
The UNT Digital Library
Environmental monitoring at the Lawrence Livermore National Laboratory. 1981 annual report
This report gives methods and results of the 1981 radiation monitoring program at LLL for both radioactive and non-radioactive contamination from gaseous and liquid effluents. Off-site monitoring includes various radionuclides but especially tritium in the ecosystems. (PSB)
Date:
March 11, 1982
Creator:
Auyong, M.; Griggs, K.S. & Buddemeier, R.W.
Object Type:
Report
System:
The UNT Digital Library
Mechanical model for ductility loss
A mechanical model was constructed to probe into the mechanism of ductility loss. Fracture criterion based on critical localized deformation was undertaken. Two microstructure variables were considered in the model. Namely, the strength ratio of grain boundary affected area to the matrix, ..cap omega.., and the linear fraction, x, of grain boundary affected area. A parametrical study was carried out. The study shows that the ductility is very sensitive to those microstructure parameters. The functional dependence of ductility to temperature as well as strain-rate, suggested by the model, is demonstrated to be consistent with the observation.
Date:
February 11, 1980
Creator:
Hu, W.L.
Object Type:
Article
System:
The UNT Digital Library
Underground muons from the direction of Cygnus X-3
We report on 3.2 years live time of underground muon observations taken between 1981 and 1989 using the Soudan 1 proportional tube detector, located at a depth of 1800 m water equivalent. The post-1984 observations are consistent with our earlier data on an excess signal apparently correlated with the Cygnus X-3 orbital period. The signal-to-background ratio in the entire data sample is 1 to 3 percent, depending on phase width. 10 refs., 2 figs., 1 tab.
Date:
September 11, 1989
Creator:
Johns, K.; Marshak, M. L.; Peterson, E. A.; Ruddick, K.; Shupe, M.; Ayres, D. S. et al.
Object Type:
Article
System:
The UNT Digital Library
Reaction rate calculations via transmission coefficients
The transmission coefficient of a wavepacket traversing a potential barrier can be determined by steady state calculations carried out in imaginary time instead of by real time dynamical calculations. The general argument is verified for the Eckart barrier potential by a comparison of transmission coefficients calculated from real and imaginary time solutions of the Schroedinger equation. The correspondence demonstrated here allows a formulation for the reaction rate that avoids difficulties due to both rare events and explicitly time dependent calculations. 5 refs., 2 figs.
Date:
July 11, 1985
Creator:
Feit, M. D. & Alder, B. J.
Object Type:
Article
System:
The UNT Digital Library
Final report for hydrologic studies support: INTERCOMP code conversion
Mass and energy balance errors noted in a number of IBM-executed problems are caused by the lack of precision in computing total mass and energy values for a domain. This problem is evident in domains constructed with highly variable mesh sizes during the early time of simulation. The machine round-off was corrected by double-precisioning certain calculations for mass and energy balance. Small differences that exist between the improved INTERCOMP code operating on an IBM machine and the old version on a CDC machine seem unimportant. The noted differences are greatest at an onset of physical system perturbation. These differences diminish rapidly with each succeeding time step. Comparisons with numerical and analytical solutions appear to prove authenticity of code results. Numerical comparisons with the CCC computer code on the Mobile experiment data demonstrate the advantage of using aquifer influence functions in place of an infinitely large mesh. The one-dimensional heat transfer in the overburden and underburden appears sufficiently accurate to describe aquifer heat losses.
Date:
January 11, 1982
Creator:
Ichimura, V.
Object Type:
Report
System:
The UNT Digital Library
Geothermal alteration of sediments in the Salton Sea scientific drill hole: Petrophysical properties and mass changes during alteration: Final report
This report has been divided into two sections. The first deals with the results of the petrophysical measurements, and the second concentrates on the distribution of alteration minerals and textures, and on a series of calculations of geochemical changes that occurred during alteration. 32 refs., 23 figs., 10 tabs.
Date:
December 11, 1987
Creator:
McDowell, S.D.
Object Type:
Report
System:
The UNT Digital Library
[Memorandum from Frank Kemerer, August 11, 1987]
Memorandum from Frank Kemerer to Julia Dunn, Barbara Jungjohan, Peter Lane, Betsy McGuire, Bruce Meeks, and Byron Medler, on August 11, 1987, informing them that Dr. Rogers Redding has accepted the assignment as Director of the Texas Academy of Math and Science. Kemerer mentions that he has turned chairmanship of the Student Affairs Committee to Barbara Jungjohan, as well as plans to expand the committee.
Date:
August 11, 1987
Creator:
Kemerer, Frank R.
Object Type:
Letter
System:
The UNT Digital Library
[Letter from Rogers Redding to James Miller, April 11, 1988]
Letter from Rogers Redding to James Miller, on April 11, 1988, informing Miller of the contributions made by members of the College of Education in interviewing TAMS finalists.
Date:
April 11, 1988
Creator:
Redding, Rogers W.
Object Type:
Letter
System:
The UNT Digital Library