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Molecular mechanisms of the epithelial transport of toxic metal ions, particularly mercury, cadmium, lead, arsenic, zinc, and copper. Progress report, January 1, 1979-December 31, 1979. [3-week-old cockerels]

Description: The purpose of the present studies was to elucidate the mechanism of lead transport, and especially the particular similarities or dissimilarities between lead and calcium in this process. The absorption of these metals was determined in 3-week old White Leghorn cockerels, raised on a commercial diet or on a specified diet, using in vivo ligated loop procedure. The dose administered into the loop contained 0.5 ..mu..Ci /sup 203/Pb (and/or 0.1 ..mu..Ci /sup 47/Ca), and 0.01 mM lead acetate (and/or 1 mM CaCl/sub 2/) in 0.5 ml 0.15 M NaCl,pH 6.5. It was shown that lead is rapidly taken up by the mucosal tissue, and slowly transferred into the body, whereas less calcium is retained by the tissue and the transfer of calcium is many times as effective as that for lead. They appear to respond in a similar manner to a low calcium intake and vitamin D treatment. Certain differences were, however, observed in the absorption process. Increasing luminal stable lead concentration from 0.01 to 1.00 mM Pb, significantly reduced the percentage of radiolead absorbed, but did not affect the absorption of calcium. Also, vitamin D enhanced the transfer of plasma /sup 47/Ca into the lumen but did not affect the transfer of plasma /sup 203/Pb. Intravenous administration of 1,25(OH)/sub 2/CC to rachitic chicks enhanced calcium and lead absorption, but the maximal absorption of these metals occurred at slightly different times after administering this metabolite, and the effect on calcium outlasted that on lead, indicating that two different transport systems may be involved. It was concluded that lead is transported across the epithelial wall by a passive diffusion and this process is affected by vitamin D in a similar manner as this vitamin affects the diffusional component of calcium transport.
Date: January 1, 1979
Creator: Wasserman, R H
Partner: UNT Libraries Government Documents Department

Self-diffusion of calcium and yttrium in pure and YF/sub 3/-doped CaF/sub 2/ single crystals

Description: Self-diffusion coefficients for Ca and Y were measured in pure and YF/sub 3/-doped CaF/sub 2/ crystals for dopant levels ranging from 2 to 10 mole %. Diffusion data were analyzed as a function of temperature and as a function of composition. Comparison of Arrhenius relationships for both Ca and Y showed that the activation energy for cation diffusion decreased approximately linearly as the YF/sub 3/ dopant level increased. Atomic jump pathways were considered and the decrease in the activation energy was explained by an increase in the constriction sizes due to Willis cluster formation. Diffusion coefficients for both cations were found to increase approximately linearly with square of the mole percent YF/sub 3/. A comparison of activation energies and diffusion coefficients for both cations in doped crystals indicated that Y required lower activation energy for diffusion than Ca but the diffusion coefficient was also lower for Y compared to Ca. The smaller activation energy for Y was explained by the smaller ionic size of Y, whereas the smaller diffusion coefficient for Y was explained on the basis of highly correlated jumps of Y ions because of interaction between Y/sub Ca/ and V/sub Ca/.
Date: July 1, 1979
Creator: Kucheria, C.S.
Partner: UNT Libraries Government Documents Department

Cross section measurement for the /sup 52/Cr(n,p)/sup 52/V reaction near threshold

Description: Cross sections for this reaction were determined in the range 5.3 to 9 MeV using a previously-reported pulsed-accelerator technique to measure gamma ray activity from 3.75 m /sup 52/V. Very few experimental data have been reported for this reaction, and little was known about the threshold region prior to the present experiment. The results of this work (in conjunction with other available cross section information) were used in the computation of fission-spectrum averages which are of interest for reactor applications.
Date: January 1, 1979
Creator: Smith, D.L. & Meadows, J.W.
Partner: UNT Libraries Government Documents Department

Decay of deformed and superdeformed nuclei formed in heavy ion reactions

Description: The importance of considering the deformation of nuclei at high angular momenta in computing transmission coefficients for their decay is examined. Deformations based on the rotating liquid drop model were used to generate transmission coefficients versus compound nucleus angular momentum. The results were then used in a Hauser-Feshbach code that included fission competition to assess the ultimate importance of deformation-modified transmission coefficients. It was found that for a broad range of prolate nuclei (superdeformed) the course of deexcitation predicted changes totally from predominant fission to predominant ..cap alpha.. decay due to a new mechanism called ..cap alpha.. decay amplification. The phase space relationships responsible for this new mechanism are presented. It is shown that this predicted new decay mode of superdeformed nuclei is consistent with a large body of existing experimental results, although more explicit experiments must be completed to confirm the new mechanism. 23 figures, 4 tables.
Date: August 1, 1979
Creator: Blann, M. & Komoto, T.T.
Partner: UNT Libraries Government Documents Department

Development of a minicomputer system for on-line processing of gamma--gamma coincidence events and measurements of E2/M1 mixing ratios in /sup 110/Cd and /sup 134/Ba

Description: A megachannel pulse-height analysis system using a 32,000-word PDP-8/E minicomputer and two moving-head disk memories was developed. The system has a storage capacity of 2/sup 18/ events at any of 2/sup 20/ data locations, is capable of processing 1,040 events/s, and provides on-line sorting and disk storage. An X- or Y- pulse-height spectrum in coincidence with one to four arithmetically combined pulse-height windows can be assembled in core for scope display and spectral analysis within 2 to 20 seconds. The software for the system was written extensively in machine language. Excellent energy and timing resolution were achieved. An energy resolution of 2.3 keV fwhm and a timing resolution of 8.5 ns fwhm were obtained for /sup 60/Co at a singles rate of 10,000 counts/s. The prompt timing peak remained Gaussian down to the fwtm by gating the TAC with SCAs which discriminated against low-energy events. The coincidence electronics also allowed on-line subtraction of accidental coincidence events. Alignment of the detectors and tests of the system's performance were made by measuring solid-angle correction factors for the Ge(Li) detectors through the correlation measurements of the 0/sup +/--2/sup +/--0/sup +/ cascade in /sup 106/Pd, and by measuring the angular spread of positron annihilation radiation coincidences. These experimental results were in excellent agreement with theoretical solid-angle correction factors calculated. Directional correlation data were obtained for gamma-ray cascades in /sup 134/Ba and /sup 110/Cd. Analyses of these data gave E2/M1 mixing ratios which are in excellent agreement with results obtained by other investigators. The improved resolution and data processing capabilities of this system gave new results for the 563-keV transition in /sup 134/Ba and the 1505-keV transition in /sup 110/Cd. E2/M1 mixing ratios of 13.3/sup +2.3/sub -1.8/ for the 563-keV transition and -1.24 +- 0.20 for the 1505-keV transition were measured.
Date: December 1, 1977
Creator: Ruhter, W.D.
Partner: UNT Libraries Government Documents Department

Properties of neutron-rich nuclei studied by fission product nuclear chemistry. [Review]

Description: A review is given of the properties of neutron-rich nuclei studied by fission product nuclear chemistry and includes the techniques used in elemental isolation and current research on the structure of nuclei near /sup 132/Sn, particle emission, and coexisting structure in both neutron-poor and neutron-rich nuclei. 35 references. (JFP)
Date: September 1, 1979
Creator: Meyer, R.A.; Henry, E.A.; Griffin, H.C.; Lien, O.G. III; Lane, S.M.; Stevenson, P.C. et al.
Partner: UNT Libraries Government Documents Department

Energy dependence of V/sub tau/ in the (p,n) reaction 10 to 30 MeV

Description: Because of the relative insensitivity of the (p,n) analog reaction to details of the nuclear wave functions, a simple description is given for the studied reaction /sup 92/Mo(p,n) at 26 MeV in which a proton is created and a neutron destroyed in the 1/sub g9/2/ orbit. The differential and angle-integrated analog cross sections and the effective potential for IF range are plotted. 27 references. (JFP)
Date: March 1, 1979
Creator: Poppe, C.H.
Partner: UNT Libraries Government Documents Department

/sup 35/Cl and /sup 81/Br nuclear magnetic resonance studies of carbonic anhydrase

Description: /sup 35/Cl NMR studies substantiated the binding of Cl/sup -/ to the Zn(II) of carbonic anhydrase. Zinc-free carbonic anhydrase was prepared and it exhibited essentially no effect on the Cl/sup -/ line width. The net Cl/sup -/ line width increased with temperature. /sup 81/Br NMR was quite similar to /sup 35/Cl in that its relaxation is dominated by quadrupolar interactions.
Date: February 1, 1979
Creator: Ward, R.L.
Partner: UNT Libraries Government Documents Department

Systematics of gamma decay through low-lying vibrational levels of even--even nuclei excited by (p,p') and (n,n') reactions

Description: A series of experiments was performed in which gamma-ray spectra were measured, using a Ge(Li) detector, for incident 7 to 26-MeV protons on the even-even vibrational nuclei /sup 56/Fe, /sup 62/Ni, /sup 64/Zn, /sup 108/Pd, /sup 110/Cd, /sup 114/Cd, /sup 116/Cd, /sup 116/Sn, /sup 120/Sn, and /sup 206/Pb, and for incident 14-MeV neutrons on natural Fe, Ni, Zn, Cd, Sn, and Pb. These measurements yielded gamma-ray cross sections from which it was inferred that almost all of the gamma cascades from (p,p') and (n,n') reactions passed down through the first 2/sup +/ levels. Consequently, the strength of the 2/sup +/ ..-->.. 0/sup +/ gamma transitions were found to be an indirect measure of the (p,p') or (n,n') cross sections. Several types of nuclear model calculations were performed and compared with experimental results. These calculations included coupled-channel calculations to reproduce the direct, collective excitation of the low-lying levels, and statistical plus pre-equilibrium model calculations to reproduce the (p,p') and the (n,n') cross sections for comparison with the 2/sup +/ ..-->.. 0/sup +/ gamma measurements. The agreement between calculation and experiment was generally good except at high energies, where pre-equilibrium processes dominate (i.e. around 26-MeV). Here discrepancies between calculations from the two different pre-equilibrium models and between the data and the calculations were found. Significant isospin mixing of T/sub greater than/ into T/sub less than/ states was necessary in order to have the calculations match the data for the (p,p') reactions, up to about 18-MeV.
Date: June 30, 1977
Creator: Koopman, R.P.
Partner: UNT Libraries Government Documents Department

Properties of multistep amplitudes in charge-exchange reactions. [Differential cross sections, analogs]

Description: A historical review is given on what is known about inelastic multistep processes in analog charge-exchange transitions at lower energies in the few tens of MeV, particularly the possibility of measuring directly with the (p,n) reaction the isovector deformation parameter. Then the expected energy dependence of multistep relative to one-step processes is shown, and an attempt is made to explain the behavior. The proton reactions on /sup 92/ /sup 100/Mo showing the analog ratio and the differential cross sections at 26 MeV and a listing of the energy dependence of the analog and analog cross sections and the two-step mechanism for analog excitation are presented. 16 references. (JFP)
Date: March 1, 1979
Creator: Madsen, V.A. & Brown, V.R.
Partner: UNT Libraries Government Documents Department

Technical Division quarterly progress report, October 1--December 31, 1977. [Fuel cycle research and development; special materials production]

Description: Results are presented on the fluidized-bed calcination of simulated radioactive waste from the reprocessing of spent commercial nuclear fuel and on the removal of actinide elements from the waste prior to calcination. Other programs include the development of storage technology for /sup 85/Kr waste; and the behavior of volatile radionuclides during the combustion of HTGR graphite-based fuel. The long-term management of defense waste from the ICPP covers post-calcination treatment of ICPP calcined waste; the removal of actinide elements from first-cycle raffinate; the retrieval and handling of calcined waste from ICPP storage vaults; and the preparation of the Programmatic Environmental Impact Statement on ICPP waste. Process improvements are reported on the Fluorinel headend process for Zircaloy-clad fuels and on uranium accountability measurements. Other development results cover the process for recovering spent Rover fuel, buried pipeline transfer systems, support to the Waste Management Program, Waste Calcining Facility support, New Waste Calcining Facility support, and effluent monitoring methods evaluation and development. In this category are studies on nuclear materials security, application of a liquid-solid fluidized-bed heat exchanger to the recovery of geothermal heat, inplant reactor source term measurements, burnup methods for fast breeder reactor fuels, absolute thermal fission yield measurements, analytical support to light water breeder reactor development, research on analytical methods, and the behavior of environmental species of iodine.
Date: February 1, 1978
Creator: Slansky, C.M. (ed.)
Partner: UNT Libraries Government Documents Department

Role of the n--p interaction in microscopic calculations of collective motion

Description: A topic of longstanding interest in nuclear structure theory has been the microscopic theory of collective nuclear behavior. There is now a large body of evidence that nuclear shell-model calculations can reproduce rotational behavior which is observed in light nuclei, particularly in the sd shell. The so-called interacting boson model which has been able to describe both rotational and vibrational behavior in intermediate and heavy nuclei, is a truncation scheme for shell-model calculations. An intrinsic assumption of the model is that the shell model is capable of describing observed collective phenomena. Recent papers have suggested that the neutron--proton interaction plays a decisive role in shell-model descriptions of rotational behavior. These arguments on the importance of n--p interaction are summarized. 6 figures, 4 tables. (RWR)
Date: January 1, 1979
Creator: McGrory, J.B.
Partner: UNT Libraries Government Documents Department

Use of fluorescent screens for isotope radiography

Description: Radiographic examination can be performed on items beyond the limitation of conventional isotope radiography without a great loss of resolution. With proper film and screen selection and scatter radiation control, fluorescent screens can be a valuable additional tool for radiography.
Date: January 1, 1979
Creator: Hubbard, S. K.
Partner: UNT Libraries Government Documents Department

Pion single charge exchange. [Angular distribution, cross sections, preliminary results, 200 MeV]

Description: The LAMPF ..pi../sup 0/ spectrometer is described, and the first results of pion single charge exchange to discrete nuclear states are discussed. Angular distribution information was obtained in /sup 3/He, and 0/sup 0/ excitation functions for the isobaric analog state were observed in targets throughout the periodic table. 8 references.
Date: January 1, 1979
Creator: Cooper, M.D.
Partner: UNT Libraries Government Documents Department

Respiratory tract tumors in Syrian hamsters following inhalation of Pu--ZrO/sub 2/ particles. [Comparison with incidence of lung tumors following intravenous injection of PuO/sub 2//ZrO/sub 2/ microspheres]

Description: Inhalation of radionuclide-bearing particles remains one of the most intensely pursued problems concerning the nuclear industry. This route of entry is generally accepted as the most probable, in case of human exposure, with ingestion being the other prominent source of concern. Many laboratory investigations, such as those reported here, continue to evaluate the possible consequences that may present health problems to the public domain. Syrian hamsters of both sexes received either inhaled (INH) PuO/sub 2//ZrO/sub 2/ particles, intravenous (IV) PuO/sub 2//ZrO/sub 2/ microspheres, a combination of INH PuO/sub 2//ZrO/sub 2/ particles and injected PuO/sub 2//ZrO/sub 2/ microspheres, or no radionuclides (controls). The INH particles and IV microspheres were tagged with ..gamma..-emitting /sup 57/Co to facilitate whole body counting and establishment of retention curves. Total lung burdens ranged from 8 nCi to 143 nCi. Significant numbers of primary lung tumors (5 to 50% per group) were induced in those animals that received INH exposures. Additional ..cap alpha.. radiation administered via Pu-laden IV microspheres had little or no effect on tumor production or nonneoplastic, degenerative changes in the respiratory tract.
Date: January 1, 1979
Creator: Thomas, R.G. & Smith, D.M.
Partner: UNT Libraries Government Documents Department

Radioactive atoms: supplement I

Description: Decay schemes and decay data are presented for 15 radioactive atomic species of special importance in the monitoring of reactor effluents. In addition to the nuclear radiations required for this purpose, there are listed the atomic radiations of additional importance to workers in the fields of nuclear medicine and health physics. Listed in tabular form are best'' values for half-lives, energies, intensities, equilibrium absorbed-dose constants, and 90% absorbed-dose ranges (in water) for each of the atomic and nuclear radiations emitted by these radioactive species. The basic data from which the best'' values were chosen, along with literature references, are also given. All data received before August 1, l973, were included. (auth)
Date: November 1, 1973
Creator: Martin, M.J.
Partner: UNT Libraries Government Documents Department

Polyketones and polysulfones for conservation in the ethylene polymer industry. Progress report No. 5, April-June 1979

Description: Reaction kinetic studies were continued on the /sup 60/Co gamma-induced polymerization of ethylene-SO/sub 2/ (Et-SO/sub 2/) mixtures. A peak in reactivity, as measured by an overall G-value of 8.4 x 10/sup 4/ molecules/100 eV, was found at 1.9 mole % SO/sub 2/ for gas-phase mixtures containing up to 6.7 mole % SO/sub 2/ and over a pressure range of 22.3 to 56.1 atm. Overall rates and G-values were obtained for liquid-phase SO/sub 2/ saturated with ethylene at up to 58.2 atm total pressure. A maximum G-value of 1.3 x 10/sup 5/ molecules/100 eV was found in the pressure range of 34.0 to 58.2 atm. Inert gases such as helium and nitrogen in Et-SO/sub 2/ gas mixtures were found to reduce peak G-values by an amount greater than could be accounted for on the basis of dilution alone. The additional effect is believed to be due to buildup of an inert gas diffusion barrier at the polymerization sites. The /sup 60/Co gamma-induced polymerization of propylene-SO/sub 2/ mixtures was investigated briefly. For the gas-phase system containing 0 to 50 mole % SO/sub 2/ in the 1 to 5 atm range, a maximum rate was found at equimolar gas composition. No other peak was found at a lower SO/sub 2/ concentration. The data indicate a power of 3 dependence of the rate on pressure and a power of 2 dependence of the G-value on pressure. A G-value of 1.38 x 10/sup 5/ molecules/100 eV was obtained for liquid SO/sub 2/ saturated with propylene at 6.24 atm. Both gas-phase and liquid-phase product analyzed approximately 1:1 molar ratio propylene/SO/sub 2/.
Date: August 1, 1979
Partner: UNT Libraries Government Documents Department