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318,998 Matching Results
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Growth regulation by macrophages
The evidence reviewed here indicates that macrophages, either acting alone or in concert with other cells, influence the proliferation of multiple types of cells. Most of the data indicate that these effects are mediated by soluble macrophage-elaborated products (probably proteins) although the role of direct cell-to-cell contacts cannot be ruled out in all cases. A degree of success has been achieved on the biochemical characterization of these factors, due mainly to their low specific activity in conditioned medium and the lack of rapid, specific assays. Understanding the growth-regulating potential of macrophages is an important and needed area of research.
Date:
January 1, 1982
Creator:
Wharton, W.; Walker, E. & Stewart, C.C.
Object Type:
Article
System:
The UNT Digital Library
Removal of $sup 137$Cs From Alkaline Condensate Wastes
None
Date:
January 1, 1968
Creator:
Mercer, B. W.; Ames, L. L. & Parkhurst, R. G.
Object Type:
Report
System:
The UNT Digital Library
Diskless LSI-11 systems
Programs for dedicated LSI-11 based systems can easily be stored in ROM instead of floppy disks, yet execute the same as disk-stored programs. Two sample systems are described.
Date:
January 1, 1982
Creator:
Ford, W. & Shirk, D. G.
Object Type:
Article
System:
The UNT Digital Library
AEC FUELS AND MATERIALS DEVELOPMENT PROGRAM. Seventh Annual Report.
This report is the seventh annual report of the unclassified portion of the Fuels and Materials Development Programs being conducted by the General Electric Company's Nuclear Materials and Propulsion Operation under Contract AT(40-1)-2847, issued by the Fuels and Materials Branch, Division of Reactor Development and Technology, of the Atomic Energy Commission. This report covers the period from January 31, 1967 to January 31, 1968, and thus also serves as the quarterly progress report for the final quarter of the year.
Date:
January 1, 1968
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Ecology of the plankton of the Chesapeake Bay. Progress report, 1 August 1974--31 July 1975. [/sup 14/C and /sup 15/N tracer studies]
None
Date:
April 1, 1975
Creator:
Taylor, W. Rowland & Taft, Jay L.
Object Type:
Report
System:
The UNT Digital Library
Sintering of polycrystalline ionic conductors:. beta. ''-Al/sub 2/O/sub 3/ and NASICON
The densification kinetics for both ..beta..''-alumina and NASICON are dramatically different. ..beta..''-Alumina sinters by a reactive liquid process whereas NASICON densifies by a solid state method. More importantly, a qualitative examination of particle and agglomerate distributions, phase composition, linear shrinkage analysis, and heating rate effects can result in a concise determination of sintering processes without recourse to more quantitative techniques. Such a simple procedural method should be a basis for any beginning investigative study into the densification mechanism of new multicomponent ceramic materials.
Date:
January 1, 1979
Creator:
McEntire, B. J.; Miller, G. R. & Gordon, R. S.
Object Type:
Article
System:
The UNT Digital Library
SURVEY OF REACTOR FACILITIES FOR PRESSURE TUBE IRRADIATION.
None
Date:
January 1, 1968
Creator:
Ard, P. A.; Heck, E. N. & McJilton, C. H.
Object Type:
Report
System:
The UNT Digital Library
Severe accident core heatup transients in modular high temperature gas-cooled reactors without operating Reactor Cavity Cooling Systems
The ultimate decay heat removal system for the current Modular High Temperature Gas-Cooled reactors is a completely passive natural convection air cooling loop. This paper considers an extremely remote accident scenario, where even this passive system fails, and heat rejection is only via a layer of thermal insulation to the reactor silo structure and the surrounding soil. The results show that even in this case the peak fuel temperatures remain well within safe limits. However, vessel and concrete temperatures can - under extreme circumstances and after several weeks - reach temperature levels at which structural failure becomes possible.
Date:
January 1, 1988
Creator:
Kroeger, P. G.
Object Type:
Article
System:
The UNT Digital Library
Examination of Uranium-2 w/o Zirconium Experimental Fuel Slugs Irradiated in EBR-I. Final Report-Program 6.1.11
Six groups of U-2 wt% Zr fuel slugs were irradiated in the first core of the EBR-I to burnups of 0.080 to 0.189 at.% at calculated temperatures of 307 to 353 deg C. Two groups of cast specimens were found to be more dimensionally stable than four groups of wrought slugs. Of the wrought slungs, the as quenched group showed less tendency to grow than the three groups which had some annealing after quenching. Specimens at burnups of about 0.189 at.% and at 383 deg C showed the onset of swelling as indicated by density measurements. The hardnesses of these specimens seemed but little affected by radiation, but there was an indication of softening with increasing irradiation temperature. (auth)
Date:
February 1, 1962
Creator:
Murphy, W. F.; Klank, A. C. & Paine, S. H.
Object Type:
Report
System:
The UNT Digital Library
The microscopic world: A demonstration of electron microscopy for younger students
None
Date:
January 1, 1991
Creator:
Horton, L. L.
Object Type:
Article
System:
The UNT Digital Library
Photoinduced Charge Separation by Polymer-Bound Chromophores
This project has examined the photodynamic behavior of water-soluble polymers that have covalently linked hydrophobic chromophores spaced along the chains. These polymeric systems have been examined for photoinduced charge separation with electron-accepting ions having different total charge. Focus has been on the excited singlet (S{sub 1}) state formed by laser flash absorption. The effects of pH and ionic strength -- factors that govern the conformational nature of the polymer in solution -- have been studied. A second major effort has been to study photoinduced redox processes involving excited states of water-soluble variants of anthracene and acridine. 27 refs., 16 figs., 2 tabs.
Date:
September 1, 1991
Creator:
Rodgers, M. A. J.
Object Type:
Report
System:
The UNT Digital Library
Structural analysis of the West Hackbery No. 6 SPR storage cavern
Four separate structural analyses of the West Hackberry No. 6 SPR storage cavern are presented. One analysis covers the creep response of the cavern beginning shortly before the time when an accidental fire occurred and proceeding through the cavern recertification pressure test. The second analysis models the surface uplife that is expected during the same pressure test. The third and fourth numerical studies investigate the structural response of West Hackberry No. 6 to slabbing and a rapid pressure drop. All analyses indicate that this cavern should be structurally stable for the conditions assumed.
Date:
August 1, 1980
Creator:
Benzley, S.E.
Object Type:
Report
System:
The UNT Digital Library
Pot Calcination Performance During First Radioactive Tests in Waste Solidification Engineering Prototypes: Waste Solidification Program. Vol. 4.
None
Date:
January 1, 1968
Creator:
McElroy, J. L.; Cooley, C. R.; DeMier, W. V.; Mendel, J. E.; Suddath, J. C. & Blomeke, J. O.
Object Type:
Report
System:
The UNT Digital Library
Numerical study of the NOL large-scale gap test
The NOL large-scale gap test has been modeled numerically using the LASL reactive hydrodynamics code 2DE with Forest Fire burn rates. The model gives good agreement between calculated and experimental critical gap values for VTQ-2 and Composition B. The calibration of peak pressure in the gap versus gap length has been obtained from these calculations, and is in good agreement with the published experimental curve. The two-dimensional nature of the gap test is evident from the curvature of the shock wave in the gap and test sample, and from the observed distance of run to detonation in the test samples.
Date:
January 1, 1980
Creator:
Bowman, A.L.
Object Type:
Report
System:
The UNT Digital Library
Compilation of cores and cuttings from U. S. Government-sponsored geothermal wells
This compendium lists the repositories holding geothermal core and well cuttings from US government-sponsored geothermal wells. Also, a partial listing of cores and cutting from these wells is tabulated, along with referenced reports and location maps. These samples are available to the public for research investigations and studies, usually following submission of an appropriate request for use of the samples. The purpose of this compilation is to serve as a possible source of cores and cuttings that might aid in enhancing rock property studies in support of geothermal log interpretation.
Date:
July 1, 1980
Creator:
Mathews, M.; Gambill, D.T. & Rowley, J.C.
Object Type:
Report
System:
The UNT Digital Library
Surprising patterns of CMOS susceptibility to ESD and implications on long-term reliability
CMOS electrostatic discharge (ESD) failures in a product where, by design, the device input terminals are not accessible to ESD led to this study of device susceptibility and an analysis of the long-term reliability of devices in assemblies from that production line. Some surprising patterns of device susceptibility are established and it is shown that the probability of long-term failure in devices whose electrical characteristics have been degraded by electrostatic discharge is small.
Date:
January 1, 1980
Creator:
Schwank, J.R.; Baker, R.P. & Armendariz, M.G.
Object Type:
Article
System:
The UNT Digital Library
Use of Analog Computers for Simulating the Movement of Isotopes in Ecological Systems
None
Date:
January 24, 1962
Creator:
Neel, R. B. & Olson, J. S.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Alkali sorber (RABSAM), September 1, 1990--August 30, 1991
The objective of this work is to develop a regenerable activated-bauxite sorber alkali monitor that requires no high-temperature/high-pressure sampling line for the reliable in situ measurement of alkali-vapor concentration in the exhaust from the pressurized fluidized-bed combustion of coal. 11 refs., 2 figs., 1 tab.
Date:
January 1, 1991
Creator:
Lee, S. H. D. & Swift, M. W.
Object Type:
Article
System:
The UNT Digital Library
Interactions of tailings leachate with local liner materials found at Canonsburg, Pennsylvania.
The mill tailings site at Canonsburg, Pennsylvania is the first mill site to receive remedial action under the Department of Energy's Uranium Mill Tailings Remedial Action Program. Part of this remedial action will require excavating the 53,500 m/sup 3/ (70,000 yd/sup 3/) of tailings on the site having a specific activity exceeding 100 pCi/g, and encapsulating these contaminated tailings in a clay-lined cell. As part of the remedial action effort, Pacific Northwest Laboratory has been studying the interactions of tailings and tailings leachate with locally occurring clays proposed for liner materials. These studies include physical and chemical characterization of amended and unamended local clays, chemical characterization of the tailings, column studies of tailings leached with deionized water, and column studies of clays contacted with tailings solutions to determine the attenuation properties of the proposed liner materials. Column studies of tailings leached with deionized water indicated that the Canonsburg tailings could represent a source of soluble radium-226 and uranium-238, several trace metals, cations, and the anions SO/sub 4/, NO/sub 3/, and Cl. Of these soluble contaminants, uranium-238, radium-226, the trace metals As and Mo, and the anions F and SO/sub 4/ were present at levels exceeding maximum concentration levels in the …
Date:
April 1, 1984
Creator:
Dodson, M.E.; Gee, G.W. & Serne, R.J.
Object Type:
Report
System:
The UNT Digital Library
Resource capture by single leaves
Leaves show a variety of strategies for maximizing CO{sub 2} and light capture. These are more meaningfully explained if they are considered in the context of maximizing capture relative to the utilization of water, nutrients and carbohydrates reserves. There is considerable variation between crops in their efficiency of CO{sub 2} and light capture at the leaf level. Understanding of these mechanisms indicate some ways in which efficiency of resource capture could be level cannot be meaningfully considered without simultaneous understanding of implications at the canopy level. 36 refs., 5 figs., 1 tab.
Date:
May 1, 1992
Creator:
Long, S.P.
Object Type:
Article
System:
The UNT Digital Library
Chemical Technology Division Unit Operations Section Monthly Progress Report, September 1961
Nine samples of ThO/sub 2/ -UO/sub 2/ prepared as part of the solgel process development studies showed no consistent effects from small variations in several process parameters. The reaction of methane and copper oxide was studied. Engineering studies of the continuous dissolution of simulated U-Zr-Sn fuels in 6.5 M NH4F, 0.6-1.0 M NH/sub 4/NO/sub 3/, 0.1 M H/sub 2/O/sub 2/ were continued in modified 6-in.-dia. equipment. A total of 1642 kg of U from NaK bonded SRE Core I fuel rods wad dejacketed to date/su Initial operability tests of the 250 ton prototype shear unit showed a number of minor modifications are warranted. Center tube temperatures measured in a vertical 64 tube electrically heated simulated fuel element bundle were very near those previously obtained in the horizontal position. A 304 SS tube containing eutectic NaK was dissolved by HF in fused saIt at a tube wall penetration rate of approximates 2 mils/hr. Partial differential equations were derived from the concentration of unreacted UF/sub 6/ as a function of time and position in a sphere of NaF during sorption of UF/sub 6/. Calcium nitrate solution was added directly to the pot calciner during Purex feeding to give smoother operation of the …
Date:
April 1, 1962
Creator:
Whatley, M. E.; Haas, P. A.; Horton, R. W.; Ryon, A. D.; Suddath, J. C. & Watson, C. D.
Object Type:
Report
System:
The UNT Digital Library
Damage nucleation in Si during ion irradiation
Damage nucleation in single crystals of silicon during ion irradiation is investigated. Experimental results and mechanisms for damage nucleation during both room and liquid nitrogen temperature irradiation with different mass ions are discussed. It is shown that the accumulation of damage during room temperature irradiation depends on the rate of implantation. These dose rate effects are found to decrease in magnitude as the mass of the ions is increased. The significance of dose rate effects and their mass dependence on nucleation mechanisms is discussed.
Date:
January 1, 1984
Creator:
Holland, O.W.; Fathy, D. & Narayan, J.
Object Type:
Article
System:
The UNT Digital Library
Statistical magnetohydrodynamics and reversed-field-pinch quiescence
A statistical model of a bounded, incompressible, cylindrical magnetofluid is presented. This model predicts the presence of magnetic fluctuations about a cylindrically-symmetric, Bessel-function-model, mean magnetic field, which satisfies del x <B> = ..mu.. <B>. As theta ..-->.. 1.56, the model predicts that the significant region of the fluctuation spectrum narrows down to a single (coherent) m = 1 mode. An analogy between the Debye length of an electrostatic plasma and ..mu../sup -1/ suggests the physical validity o the model's prediction of <deltaB(r)deltaB(r')> when /r - r'/ greater than or equal to ..mu../sup -1/.
Date:
January 1, 1982
Creator:
Turner, L.
Object Type:
Article
System:
The UNT Digital Library
Search for the neutrinoless muon decay. mu. /sup +/. -->. e/sup +/. gamma
Separate muon, electron, and tau numbers are conserved in the minimal standard model of electroweak interactions with massless neutrinos. However, in many extensions to the standard model, separate lepton numbers are not expected to be conserved quantities. A new search for muon number non-conserving processes has been undertaken at the Los Alamos Meson Physics Facility (LAMPF), specifically to look for three neutrinoless decay modes of the muon. The search for the decay of a muon to an electron and a photon is discussed here. A new detector facility, located in the LAMPF stopped muon channel, was developed for this experiment. This Crystal Box detector consists of a cylindrical drift chamber surrounded by a plastic scintillator hodoscope and a large solid angle, modularized, NaI(Tl) calorimeter. The apparatus measures the trajectories, relative timing, and energies of charged particles and photons from the decays of positive muons stopped in a central target. The assembly and calibration of the detector are described, and the procedure for taking data is discussed. The sample of 1.3 million candidate events, from the first data run of the Crystal Box, was analyzed using a maximum-likelihood method. The upper limit on the branching ratio, relative to normal muon decay, …
Date:
July 1, 1985
Creator:
Wilson, S.L.
Object Type:
Report
System:
The UNT Digital Library