In experiments related to the development of the electron-ring accelerator, electrons were injected into a pulsed magnetic field to form rings that were then compressed radially to a small size. The injected beam had a current of about 150 A at an energy of 3.3 MeV with an energy spread of {+-} 0.1% and a pulse length duration of 20 nsec. At low intensity, an increase in the minor radius of the ring and a large loss of electrons was observed to occur during the compression cycle. At high intensity, cooperative phenomena that caused a large increase in the energy spread accompanied by particle loss were observed. Theoretical interpretation of these observations suggests that the primary source of electron loss and enlargement of the axial dimension was the crossing of single-particle resonances during compression in the presence of large magnetic field nonlinearities and perturbations. The cooperative phenomena are interpreted as resulting from a negative mass instability. Despite the large minor radius and small number of electrons, experiments on extracting the ring were performed; under acceleration the ring failed to retain its integrity because of inadequate self-focusing.

The hydrocarbon content of leaf fossils from Iceland has been investigated by gas chromatography-mass spectrometry. The distribution patterns of normal hydrocarbons, branched hydrocarbons, and cyclic hydrocarbons are compared to those of present-day living organisms. The diagenetic pathways of these hydrocarbons are discussed.

The authors have measured the polarization parameter P in neutron-proton elastic scattering near the backward direction, using a polarized proton target. Measurements covered the range of incident neutron moment from 1.0 to 5.5 GeV/c and of four-momentum transfer squared u from -0.005 to -0.5 (GeV/c){sup 2}. Forward going protons were detected by means of a wire-spark-chamber spectrometer. Slow neutrons near 90 deg lab angle were detected in coincidence by means of an array of plastic scintillation counters. P was determined from the change in counting rate I of scattered particles upon reversal of the target polarization P{sub T} according to I = I{sub 0}[l + P(P{sub T} {center_dot} k incident neutron x k final neutron/sin {theta} final neutron)]. They find that P is consistently negative and shows no marked structure as a function of u and of incident momentum. The data roughly follow the simple form P = -0.5 {radical}-u/m{sub p}.

A calculation is given of the radiated energy loss from a charged rod which moves at constant speed past an infinite set of parallel semi-infinite conducting plates of infinitesimal thickness, with the rod taken parallel to and at a fixed distance from the plate edges. The problem is analyzed using the Wiener-Hopf technique, and the resulting formulas are evaluated analytically in the limits of high rod speed and low rod speed, and compared with numerical evaluation over the full range of speeds.

In one mode of operation of an electron ring accelerator (ERA), at the end of compression rings are slowly moved through the radial integral betatron resonance Q{sub r} = 1. Although the coherent radial oscillation frequency of the ring as a whole remains below unit, the oscillation frequencies of individual electron are (incoherently) caused to pass through the resonance because of the additional focusing from ions trapped in the ring. In this paper the effect of field errors on ring major and minor radii is evaluated--theoretically--for the cases in which the spread in the square of the electron oscillation frequency ({Delta}{sup 2}) is (a) much larger and (b) much smaller than the contribution to the square of the oscillation frequency from the ions ({Lambda}{sup 2}). It is shown that for the ERA, where case (b) applies, the increase in ring minor dimensions, for given field errors and rate of resonance crossing, is less than in case (a) by a factor of ({Delta}/{Lambda}){sup 2}. Numerical examples show that the degradation of ring quality in case (b) should, with suitable attention to the design and construction of the ERA apparatus, be acceptably small.

We discuss the possibility of using synchrotron radiation to form electron rings having a very high electric field to hold the ions inside the ring. The formulas describing bow the energy and the dimension of the ring change under the effect of synchrotron radiation are derived, and a numerical example is given.

The carcinogenic activity of the benzo[a]pyrene 1, the 7,12-dimethylbenz[a]anthracene 2 and the 3-methylcholanthrene 3 is suggested to be determine by the electrophilic attack of the active oxygen, induced by the hydroxylating enzyme systems, on the most reactive substituting carbon atom(s). The cationic intermediate(s) with the charge mainly localized on a complementary, interrelated position(s) of the hydroxyl substituted position(s) reacts further with the cellular nucleophiles. The electrophilic nature of the ultimate chemical carcinogens constitutes the common distinctive feature that correlates their different structures and allows us to understand their carcinogenicity. The formation of a covalent bond with the nucleophiles of the biological macromolecules, nucleic acids and proteins, appears to be the essential requirement in the primary process of carcinogenesis.

The production of high energy (multi-GeV) proton beams by an electron ring accelerator is considered. Both the final energy and intensity of the proton beam depend on the choice of parameters for the electron ring. Possible sets of parameters, consistent with all the known requirements of ring stability, and which optimize the energy and (or) the intensity of the proton beam, are presented.

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The possibility of using the collective field of a large number of electrons to effect the acceleration of protons to high energies in a compact accelerator--or to permit acceleration of heavier ions in a manner not critically dependent on the charge-to-mass ratio of these ions--has been noted in an earlier Comment. A most attractive conceptual form for such an accelerator is the electron ring accelerator (ERA) and in the present Comment they direct attention to the basic phenomena--insofar as they know them--that govern the design and operation of an ERA. Briefly, the ERA concept visualizes the use of a compact ring of relativistic electrons that circulate in a plane perpendicular to an external magnetic field. The ring is partially neutralized by ions held in the potential well of the electrons. The electric field of these ions and the magnetic attractive forces between the circulating electrons then together act to overcome the electrostatic repulsion of the electrons and make possible the achievement of a configuration that is self-stable in the absence of external focusing fields. Acceleration of the ring with its accompanying ions, in a direction perpendicular to the plane of the ring, can be achieved (at the expense of the …

The procaryotic photosynthetic microorganisms Anacystis nidulans, Nostoc and Rhodospirillum rubrum have cell walls and membranes that are resistant to the solution of methane in their lipid components and intracellular fluids. But Anacystis nidulans, possesses a limited bioxidant system, a portion of which may be extracellularly secreted, which rapidly oxidizes methane to carbon dioxide. Small C{sup 14} activities derived from CH{sub 4} in excess of experimental error are detected in all the major biochemical fractions of Anacystis nidulans and Nostoc. This limited capacity to metabolize methane appears to be a vestigial potentiality that originated over two billion years ago in the early evolution of photosynthetic bacteria and blue-green algae.

Fluorescence properties of purified isoleucyl-tRNA-synthetase isolated from E. coli B have been studied. No changes in the quantum yield, energy or polarization of the emission were detected in the presence (either individually or in combinations) of the substrates and cofactors required for activation of L-isoleucine. In 2.5 M urea enzyme activity and intrinsic fluorescence intensity (at 340 nm) each decrease with time, showing similar kinetics and rate constants. The rate of this decay is reduced in the presence of ligands which can bind to the enzyme and the effect has been used to measure dissociation constants for enzyme-ligand complexes. Values have been obtained for the complexes between enzyme and L-isoleucine (K{sub diss} = 2.5 x 10{sup -5} M), L-valine (K{sub diss} = 3.0 x 10{sup -4} M), ATP (K{sub diss} = 1.5 x 10{sup -4} M) and PP{sub i} (K{sub diss} = 2.0 x 10{sup -4} M) at 25{sup o}. The effects of ionic strength, and the temperature dependence and urea concentration dependence of L-isoleucine binding have also been studied. Magnesium ions, which are required for catalysis, do not greatly affect the binding of single substrates, but changes are seen in the presence of ATP and L-isoleucine together. The magnesium …

The authors have searched for an asymmetry in the inelastic scattering of electrons from a polarized proton target in the region of resonance excitation, at values of four-momentum transfer squared of 0.4, 0.6 and 1.0 (GeV/c){sup 2}. Data were also taken using an incident positron beam in order to distinguish any possible effect of time-reversal violation from that due to higher-order ({alpha}{sup 3}) contributions to the scattering. No sizeable violation of time-reversal invariance was found.

Irradiation of benzo[a]pyrene 1 with 1-methylcytosine hydrochloride 2a (molar ratio 1:10) at 3500 {angstrom} in methanol-acetone produces the 6-(1-methylcytos-5-yl)-benzo[pa]pyrene 3. The structure of the photoproduct shows the hydrocarbon bound through the most active 6-carbon atom to the nucleophilic 5-position of the base. The specific substitution of both moieties combined with other data allows them to understand the carcinogenic activity of the hydrocarbon and thereby to propose a possible mechanism of their linkage in vivo. In this model, the K region does not play a role in triggering the cancer process.

A statistical approach is proposed to validation of SHAC models. It includes a definition of validation, an explanation of its purposes, and a description of the statistical aspects of experimental design. It proposes a study to validate design codes with statistical samples of real-world systems. Also included is a summary of present SHAC validation methodologies and studies as well as recommendations for future activity.

A summary of measured data collected by numerous agencies cooperating in the Piledriver event, is presented together with calculations based on empirical relations deduced from past events in comparable media. Of 9 relations that have been proposed to predict cavity radius, 5 result in radii accurate to <3.5%. The remainder are off by about 10 to 18%. Three postshot recovered cores (U-15.01 PS-1, -2, -3) were examined on a gross scale prior to extensive detailed sampling for laboratory tests. The positions of injected glass seams, radioactivity, and shear zones were recorded. The orientation of several thousand core fractures was measured with respect to the core axes and distance from the shot point. Taking all observations into account, phenomena related to failure of rock is the Piledriver event are closely related to pre-existing weaknesses and inhomogeneities. (Longer abstract available)

A study was performed of the correlation between fuel form stability and exposure environment of (temperature and atmosphere). 100% Tm/sub 2/O/sub 3/, 80% Tm/sub 2/O/sub 3//20% Yb/sub 2/O/sub 3/ and 100% Yb/sub 2/O/sub 3/ wafers were subjected to air, dynamic vacuum and static vacuum at temperatures to 2000/sup 0/C for times to 100 hours. Results showed the Tm/sub 2/O/sub 3//Yb/sub 2/O/sub 3/ cubic structure to be unaffected by elemental levels of iron, aluminum, magnesium and silicon and unaffected by the environmental conditions imposed on the wafers. A second task emphasized the optimization of the thermal, mechanical and chemical stability of Tm/sub 2/O/sub 3/ fuel forms. Enhancement was sought through process variable optimization and the addition of metal oxides to Tm/sub 2/O/sub 3/. CaO, TiO/sub 2/ and Al/sub 2/O/sub 3/ were added to form a grain boundary precipitate to control fines generation. The presence of 1% additive was inadequate to depress the melting point of Tm/sub 2/O/sub 3/ or to change the cubic crystalline structure of Tm/sub 2/O/sub 3//Yb/sub 2/O/sub 3/. Tm/sub 2/O/sub 3//Yb/sub 2/O/sub 3/ wafers containing CaO developed a grain boundary phase that improved the resistance to fines generation. The presence of Yb/sub 2/O/sub 3/ did not appear to …

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A feasibility study was performed on encapsulated thulium-170 as an isotopic fuel for operation at temperatures to 1500/sup 0/C for 180 days. Effects of various combinations of fueled capsule design parameters were evaluated and compard to experimental data. A computer program was developed to predict dose rates through various thicknesses of aluminum, stainless steel, lead, tungsten and depleted uranium absorbers using thermoluminescent dosimetry techniques for experimental corroboration. A procedure for preparing Tm/sub 2/O/sub 3//Yb/sub 2/O/sub 3/ composites was evaluated. Melting points and solid-state transformations to the melting point of a composition series 100% Tm/sub 2/O/sub 3/ - 100% Yb/sub 2/O/sub 3/ were determined. The Tm/sub 2/O/sub 3/ - 100% Yb/sub 2/O/sub 3/ system remains cubic to the melting point. Solid-state reaction of candidate containment materials (Hastelloy X, Hastelloy C-276, Haynes-25, T-111, TZM, tungsten and zirconium) with Tm/sub 2/O/sub 3//Yb/sub 2/O/sub 3/ were studied. Containment for times to 10,000 hours at 1600/sup 0/C and to 500 hours at 2000/sup 0/C were demonstrated.

The scope of this research program is to study the structure of nuclei and the properties of the nuclear force, in particular its symmetries, using the tools of nuclear spectroscopy. To this end a unique set of instruments is at disposal, including curve crystal diffraction monochromators, high resolution beta spectrometers and Moessbauer spectrometers.

The EPR spectrum of single ions of /sup 143/Nd in a crystal of Neodymium Ethyl Sulfate, predominantly of isotope /sup 142/Nd, was observed under condition of very high Boltzmann factor, i.e., high fields and low temperatures. It was found that the interactions with neighboring ions displaced the hyperfine lines from uniform spacing, and that by measuring the deviation it was possible to find the nearest neighbor interaction. The departure from a purely magnetic dipolar interaction is smaller than previous measurements would indicate. It was found that EPR resonance at large values of H/T in magnetically concentrated crystals can yield accurate values of spin-spin interactions.

Radiation dose rates from three thulium-170 oxide sources (20.7, 10.0 and 5.0 thermal watts) were measured through three thicknesses (1/4, 1/2 and 1 inch) of absorber by thermoluminescent dosimetry techniques. Absorber materials used were aluminium, stainless steel, lead, tungsten and depleted uranium. Resultant radiation doses were measured at 19 and 100 cm. Comparison of theoretical dose rates calculated by computer with measured dose rates validated the calculation technique for lead, tungsten and uranium absorbers but not for aluminum and stainless steel. Use of infinite medium build-up factors (B/sub infinity/) was thus validated in computation of dose rates for lead, tungsten and uranium absorbers; use of B/sub infinity/ in computation of dose rates for aluminum and stainless steel absorbers overestimated dose rates vis-a-vis experimentally determined dose rates by an approximate factor of 2.

Proton hole states in the 1f/sub 7/2/ nuclei /sup 46/Ti, /sup 54/Fe, /sup 56/Fe, /sup 58/Ni, and /sup 60/Ni have been studied with the (p,2p) reaction with 46-MeV protons. The measured binding energies and angular correlations are consistent with the binding energies and orbital angular momentum assignments (1f/sub 7/2/, 2s/sub 1/2/, and 1d/sub 3/2/) obtained from proton pick-up reactions. 3 figures, 1 table.

The purpose of this analysis is to determine if the two piece flat head closure concept presently being considered by INC for the LOFT reactor vessel will meet the structural and fatigue requirements of Article 4 of Section III, ''Nuclear Vessels,'' of the ASME Boiler and Pressure Vessel Code, for the anticipated LOFT operational requirements. The analyses performed include stress analyses based on classical stress analysis methods and proven computer programs, fatigue analyses based on the fatigue criteria of Section III of the Code, and thermal analyses based on multi-dimensional computer programs.