Showing papers by "Argonne National Laboratory published in 1982"
TL;DR: In this article, both time-independent and time-dependent Hamiltonian models are constructed on a finite lattice of spin-1/2 systems, where different regions of the lattice correspond to different components of the Turing machine (plus recording system).
Abstract: Quantum mechanical Hamiltonian models, which represent an aribtrary but finite number of steps of any Turing machine computation, are constructed here on a finite lattice of spin-1/2 systems. Different regions of the lattice correspond to different components of the Turing machine (plus recording system). Successive states of any machine computation are represented in the model by spin configuration states. Both time-independent and time-dependent Hamiltonian models are constructed here. The time-independent models do not dissipate energy or degrade the system state as they evolve. They operate close to the quantum limit in that the total system energy uncertainty/computation speed is close to the limit given by the time-energy uncertainty relation. However, the model evolution is time global and the Hamiltonian is more complex. The time-dependent models do not degrade the system state. Also they are time local and the Hamiltonian is less complex.
375 citations
TL;DR: In this paper, quantum mechanical Hamiltonian models of Turing machines are constructed on a finite lattice of spin-textonehalf{} systems, and they operate at the quantum limit in that the system (energy uncertainty)/(computation speed) is close to the limit given by the time-energy uncertainty principle.
Abstract: Quantum mechanical Hamiltonian models of Turing machines are constructed here on a finite lattice of spin-\textonehalf{} systems. The models do not dissipate any energy and they operate at the quantum limit in that the system (energy uncertainty)/(computation speed) is close to the limit given by the time-energy uncertainty principle.
273 citations
TL;DR: In this paper, the Haven Ratio is used to extract unique information about the diffusion mechanism in ionic conductors and the historical background for such measurements, their present status, results, and the current theories of interpretation are discussed in detail with emphasis on the special problems found in fast ionic conductsors.
255 citations
TL;DR: In this paper, a method is proposed to derive the combination of slip systems that fulfills both the boundary conditions and the yield conditions for any particular crystal orientation, and the magnitude of the free shears as well as the resulting orientation change follow from kinematics.
234 citations
TL;DR: In this article, a model that combines possible aging effects on the friction stress and on forest hardening is proposed, and the dependence of both static and dynamic strain-aging on strain is predicted and compared with available experimental information.
216 citations
TL;DR: In this paper, the authors used rare gas matrix isolation techniques in combination with extended x-ray absorption fine structure (EXAFS) to study the variation in interatomic distances for small Fe molecules in solid neon.
Abstract: We have used rare gas matrix isolation techniques in combination with extended x-ray absorption fine structure (EXAFS) to study the variation in interatomic distances for small Fe molecules in solid neon. A considerable contraction in the interatomic distances was observed for the metal molecules. An Fe-Fe distance of 2.02 \ifmmode\pm\else\textpm\fi{} 0.02 \AA{} for the lowest concentration of metal was observed. This is in good agreement with early EXAFS measurements in ${\mathrm{Fe}}_{2}$-Ar. We also carried out a careful study of the x-ray-absorption near-edge structure (XANES), and observed the appearance of considerable structure for a 1.5-at.% Fe sample. The XANES spectra were analyzed in terms of $1s$-to-($3d,4s$) and $1s$-to-$4p$ transitions.
196 citations
TL;DR: In this article, the exchange-correlation energy of electron-hole liquid (EHL) is shown to be independent of different band characteristics of semiconductors, and a simple expression for the EHL energy in all semiconductor devices is given.
Abstract: Exchange-correlation energy of electron-hole liquid (EHL) is shown to be independent of different band characteristics of semiconductors. A simple expression of ${\ensuremath{\epsilon}}_{\mathrm{xc}}$ for EHL in all semiconductors is given. In units of excitonic rydberg, ${\ensuremath{\epsilon}}_{\mathrm{xc}}=\frac{(a+{\mathrm{br}}_{s})}{(c+{\mathrm{dr}}_{s}+{r}_{s}^{2})}$, where $a=\ensuremath{-}4.8316$, $b=\ensuremath{-}5.0879$, $c=0.0152$, and $d=3.0426$. Ground-state and thermodynamic properties calculated with this expression are in good agreement with earlier theoretical calculations and experimental results.
191 citations
TL;DR: More realistic estimates of the deposition velocity, for aerosol particle deposition on natural water surfaces, are obtained by modifying earlier resistance models to include the effects of wave breaking and spray formation in high winds and particle growth in the humid regions near the air/water interface as mentioned in this paper.
179 citations
TL;DR: In this paper, neutral bifunctional extractants, alkyl(phenyl)-N,N-dialkyl carbamoylmethylphosphine oxides, have been prepared and studied as extractants for Am(III) from nitric acid media.
Abstract: A new series of neutral bifunctional extractants, alkyl(phenyl)-N,N-dialkylcarbamoylmethylphosphine oxides, has been prepared and studied as extractants for Am(III) from nitric acid media. Two types of alkyl(phenyl)-N,N-dialkyl CMPO compounds were prepared, one containing N,N-diethyl groups and the other containing N,N-diisobutyl groups. The N,N-diethyl series contained hexyl(phenyl) and 6-methylheptyl(phenyl) derivatives, abbreviated HφDECMPO, and 6-MHφDECMPO, respectively. The N,N-diisobutyl series contained the n-octyl(phenyl), 6-methylheptyl(phenyl), and the 2-ethylhexyl(phenyl) derivatives, abbreviated OφD[IB]CMPO, 6-MHφD[IB]CMPO, and 2-EHφD[IB]CMPO, respectively. Third power extractant dependencies for the extraction of Am(III) from 0.5 and 3 M HNO3 were obtained at low (<0.25 M) concentrations of extractant, but higher power dependencies were obtained above 0.25 M extractant from 3 M HNO3. The HφDECMPO, 6-MHφDECMPO, 6-MHφD[IB]CMPO, and OφD[IB]CMPO [all 0.5 M in diethylbenzene (DEB)] are si...
179 citations
TL;DR: In this article, a correlation based on the isotropic-elastic, line-tension approximation was developed to describe the void bypassing stresses in quantitative fashion, with an appropriate choice of the several arbitrary parameters in the line tension description, elastic anisotropy and the various interactions can be included.
176 citations
TL;DR: In this article, the conditions necessary for efficient, small-scale separation of coal macerals are investigated, and an isopycnic density gradient centrifugation (DGC) technique is used to isolate pure macers.
TL;DR: In this paper, a new formulation of lattice gauge theory without explicit path integrals or sums is obtained by using the microcanonical ensemble of statistical mechanics, where expectation values in the new formalism are calculated by solving a large set of coupled, nonlinear, ordinary differential equations.
Abstract: A new formulation of lattice gauge theory without explicit path integrals or sums is obtained by using the microcanonical ensemble of statistical mechanics. Expectation values in the new formalism are calculated by solving a large set of coupled, nonlinear, ordinary differential equations. The average plaquette for compact electrodynamics calculated in this fashion agrees with standard Monte Carlo results. Possible advantages of the microcanonical method in applications to fermionic systems are discussed.
TL;DR: Reduction of the dose rates of fission-spectrum neutrons has no effect on cell killing but increases transformation frequency, suggesting that the risk of cancer induction due to work-related exposure to neutrons in the nuclear power industry may be greater than previously thought.
Abstract: We have studied the effect of reduced dose rates of radiation on neoplastic transformation using the C3H/1OT1/2 mouse embryo-derived cell line developed by Reznikoff et al.1. In this cell system, transformation can be measured by scoring the foci of piled-up cells that occur after the loss of contact inhibition of growth. We report here that reduction of the dose rates of fission-spectrum neutrons (of mean energy 0.85 MeV) from 38.5 or 10.3 to 0.43 and 0.086 rad min−1 has no effect on cell killing but increases transformation frequency. These data are in contrast to previously published results obtained with 60Co γ rays where reduction of the dose rate resulted in a marked reduction in transformation frequency2,3. Although cancer induction in man involves many factors besides those at the cellular level, the implication from our findings is that the risk of cancer induction due to work-related exposure to neutrons in the nuclear power industry may be greater than previously thought.
TL;DR: This work approaches the problem of estimating Hessian matrices by differences from a graph theoretic point of view and shows that both direct and indirect approaches have a natural graph coloring interpretation.
Abstract: Large scale optimization problems often require an approximation to the Hessian matrix. If the Hessian matrix is sparse then estimation by differences of gradients is attractive because the number of required differences is usually small compared to the dimension of the problem. The problem of estimating Hessian matrices by diferences can be phrased as follows: Given the sparsity structure of a symmetric matrix $A$, obtain vectors $d_{1},d_{2},\ldots,d_{p}$ such that $Ad_{1},Ad_{2},\ldots,Ad_{p}$ determine $A$ uniquely with $p$ as small as possible. We approach this problem from a graph theoretic point of view and show that both direct and indirect approaches to this problem have a natural graph coloring interpretation. The complexity of the problem is analyzed and efficient practical heuristic procedures are developed. Numerical results illustrate the differences between the various approaches.
TL;DR: Eddy-correlation measurements with a newly developed fast-response NOx sensor indicate that the deposition velocity at a height of about 6m above a soybean field has a maximum value near 0.6cms-1 for NOx and is usually about 2/3 of that found for ozone as discussed by the authors.
TL;DR: In this article, a linear polarized modulated structure with a wavelength of approximately 100 A is observed, where the modulated moment increases faster than the ferromagnetic moment down to 0.71 K, and then disappears suddenly, with loss of superconductivity and a transition to a normal Ferromagnetic state.
Abstract: Neutron diffraction and resistivity measurements on single crystals of ErRh/sub 4/B/sub 4/ have revealed that both superconductivity and ferromagnetic order coexist in this material between 0.71 K and 1.2 K. In this intermediate phase, a linear polarized modulated structure with a wavelength of approximately 100 A is observed. The modulated moment increases faster than the ferromagnetic moment down to 0.71 K and then disappears suddenly, with loss of superconductivity and a transition to a normal ferromagnetic state. This transition is accompanied by temperature hysteresis of about 60 mK. The same hysteresis, in the inverse sense, is exhibited by the ferromagnetic component. The intermediate phase is interpreted as being one of coexisting normal ferromagnetic domains and superconducting sinusoidally ordered domains.
TL;DR: In this article, the elastic constants of Nb/Cu superlattices were found to be correlated with changes in the electrical resistivity of the samples giving the first evidence that electronic effects are responsible for phonon softening in these materials.
Abstract: Brillouin-scattering measurements show an anomalous dip in the elastic constants of Nb/Cu superlattices for superlattice wavelengths of \ensuremath{\lesssim} 100 \AA{}. This dip is correlated with changes in the electrical resistivity of the samples giving the first evidence that electronic effects are responsible for phonon softening in these materials.
TL;DR: In this article, the authors studied the effect of crystal structure on displacement mixing at Ni•Si interfaces as a function of dose, temperature, and dose rate, and found that the activation enthalpy for the temperature-dependent part is ∼ 0.09 eV.
Abstract: Ion‐beam mixing at Ni‐Si interfaces was studied as a function of dose, temperature, and dose rate. In the temperature range 10–443 K, the thickness of the mixed Ni‐Si layer grew proportionally to the square root of dose for 250‐keV Ar+ and 280‐keV Kr+ irradiations. The apparent diffusion coefficient for mixing during irradiation comprises temperature‐dependent and independent contributions. The activation enthalpy for the temperature‐dependent part is ∼0.09 eV. Varying the dose rate by a factor of ∼20 had little effect upon mixing at either 80 or 368 K. Analysis of these results using chemical rate theory showed that the low activation enthalpy for diffusion was not associated with point‐defect motion. More likely the temperature dependence of mixing in Ni‐Si is associated with the effect of temperature on compound formation. The results for mixing at 10 K in Ni‐Si were compared with those in Ni‐Al, at 10 K, to study the effect of crystal structure on displacement mixing.
TL;DR: The induction of single‐strand breaks in the DNA of Bacillus subtilis irradiated in vivo by monochromatic UV light at wavelengths from 254 to 434 nm was measured, showing measurable breaks in extracted DNA are induced at a higher frequency than those induced in vivo.
Abstract: — The induction of single-strand breaks (alkali-labile bonds plus frank breaks) in the DNA of Bacillus subtilis irradiated in vivo by monochromatic UV light at wavelengths from 254 to 434 nm was measured. The spectrum consists of a major far-UV (below 320 nm) component and a minor near-UV shoulder. A mutant deficient in DNA polymerase I accumulates breaks caused by near-UV (above 320 nm) wavelengths faster than the wild-type strain proficient in polymerase I. Measurable breaks in extracted DNA are induced at a higher frequency than those induced in vivo. Anoxia, glycerol, and diazobicyclo (2.2.2.) octane inhibit break formation in extracted DNA. Alkali-labile bonds induced by 365-nm UV radiation are largely (78%) covalent bond chain breaks, the remainder consists of true alkali-labile bonds, probably apurinic and apyrimidinic sites.
TL;DR: 2-step superlinear convergence is proved to be the final stage of a ‘global’ method to solve the nonlinear programming problem and is compared (theoretically) to the popular successive quadratic programming approach.
Abstract: In this paper we consider the final stage of a ‘global’ method to solve the nonlinear programming problem. We prove 2-step superlinear convergence. In the process of analyzing this asymptotic behavior, we compare our method (theoretically) to the popular successive quadratic programming approach.
TL;DR: In this paper, a simple molecular field model is presented for the prediction of magnetic transition temperatures of rare-earth (RE) compounds when crystalline electric field (CEF) splittings are significant.
TL;DR: The transfer technique constitutes a generally useful immunological “third‐dimension” in the high‐resolution separation of proteins and seems likely that a large majority of proteins retain sufficient conformation throughout the analytical procedure (or can regain it easily afterwards) to be recognized immunologically.
Abstract: Human plasma proteins separated by high-resolution two-dimensional electrophoresis have been electrophoretically transferred to sheets of nitrocellulose using a modification of the method of Towbin, Staehelin, and Gordon [8]. Although the proteins have been denatured in sodium dodecyl sulfate and separated into subunits, the nitrocellulose-bound molecules still react with appropriate specific antisera even after storage of the transfer in air at room temperature for 5 months. Of 25 proteins whose location in the pattern had been previously determined, 24 are specifically revealed on transfers of whole plasma patterns by appropriate antiserum. In addition, 6 previously unidentified proteins (prothrombin, C1s, C4γ, C1s inhibitor, Ig J-chain, and a1AP glycoprotein) have been identified in the pattern for the first time using the transfer technique. It therefore seems likely that a large majority of proteins (> 96 % in this study) retain sufficient conformation throughout the analytical procedure (or can regain it easily afterwards) to be recognized immunologically. The transfer technique thus constitutes a generally useful immunological “third-dimension” in the high-resolution separation of proteins. Of three monoclonal antibodies similarly tested, none could detect antigen transferred to nitrocellulose from a two-dimensional gel, while each bound specifically to the appropriate antigen absorbed in native form to the nitrocellulose.
TL;DR: Oxygen-Pd(100) interactions were studied by means of LEED, AES and ELS to characterize the initial oxidation and elucidate the relationship between surface-oxide reconstructions and bulk oxidation as discussed by the authors.
TL;DR: For an arbitrary number of particles an explicit construction for direct interactions satisfying cluster separability (macrolocality) is given in this article, where the Hamiltonian is in many ways similar to the nonrelativistic many-body Hamiltonian.
Abstract: For an arbitrary number of particles an explicit construction is given for direct interactions satisfying cluster separability (macrolocality). The Hamiltonian is in many ways similar to the nonrelativistic many-body Hamiltonian. Under conditions of physical interest the strength of the N-body interaction decreases rapidly with increasing N.
Journal Article•
TL;DR: In this paper, a pure speciment of analcime whose composition was Na/sub 0.96/Al/sub 1.04/O/sub 6/H/sub 2/O and on the corresponding anhydride was analyzed.
Abstract: Calorimetric measurements have been carried out on a pure speciment of analcime whose composition was Na/sub 0.96/Al/sub 0.96/Si/sub 2.04/O/sub 6/.H/sub 2/O and on the corresponding anhydride. The low-temperature heat capacity, standard enthalpy of formation (298.15 K), and high-temperature enthalpy increments have been determined by adiabatic, solution, and drop-calorimetric techniques, respectively. Thermodynamic functions have been calculated for analcime (to 600 K) and for dehydrated analcime (to 1000 K).
TL;DR: The main changes are that the system undergoing the evolution corresponding to T iterations becomes three systems corresponding to the internal machine, the computation tape, and computation head, and the copy phase becomes more complex.
Abstract: Work done before on the construction of quantum mechanical Hamiltonian models of Turing machines and general discrete processes is extended here to include processes which erase their own histories. The models consist of three phases: the forward process phase in which a mapT is iterated and a history of iterations is generated, a copy phase, which is activated if and only ifT reaches a fix point, and an erase phase, which erases the iteration history, undoes the iterations ofT, and recovers the initial state except for the copy system. A ballast system is used to stop the evolution at the desired state. The general model so constructed is applied to Turing machines. The main changes are that the system undergoing the evolution corresponding toT iterations becomes three systems corresponding to the internal machine, the computation tape, and computation head. Also the copy phase becomes more complex since it is desired that this correspond also to a copying Turing machine.
TL;DR: Using liposomes differing in size and lipid composition, this work has studied the uptake characteristics of the liver parenchymal and Kupffer cells and found that liposome made with a galactolipid as part of the lipid constituents appeared to have higher affinity to paren chymal cells thanliposomes made without the galactolinipid.
TL;DR: In this paper, a detailed incident angle modifier, K ατ ( θ l, θ t ), for reflecting concentrators, can be approximated accurately by the product of two projected angle factors, where t and l are projected angles between the sun's position vector and the collector normal.
TL;DR: In this article, a quasi-Eulerian finite element formulation for the analysis of transients in a fluid with a pressurized bubble is developed in both two and three dimensions, which can be programmed to move independent of the material, so that the method lends itself well to the treatment of fluid-structure problems.
TL;DR: In this article, the Stenhouse-Grout structure factor model for amorphous carbon was used to show that the amount of tetrahedral bonding is negligible in the degenerate case.
Abstract: Neutron diffraction data show there isllittle tetrahedral bonding in glassy carbon, and correspond to the Stenhouse-Grout structure factor model for amorphous carbon taking the degenerate case in which the amount of tetrahedral bonding is negligible. This is in contrast to the X-ray results of Noda and Inagaki. Further analysis of the radial distribution function from the neutron diffraction data is presented. A brief summary of other X-ray diffraction measurements on a variety of amorphous carbons is given, all of which confirm the predominantly trigonal coordination. The disagreement of the earlier X-ray and electron diffraction measurements is due to the poor resolution and normalization of the data, and also perhaps the method of preparation. The amount of tetrahedral bonding present in amorphous carbon requires careful diffraction measurements at large scattering vectors to enable better resolution of the peaks in the radial distribution function.