Second-order Mass Research Articles

A Study on the Prediction of Roundness Variation in Honing Using Hone Dynamics

Abstract This paper describes the simulation for estimating roundness variation according to the process variables in the honing process based on hone dynamics. Honing experiments were carried out to confirm the simulation results. The mandrel rotation speed and the workpiece stroke speed were treated as the main parameters in the simulation and the experiment. The honing force, which varies dynamically in the contact between the honing tool and workpiece, is the main cause of roundness variation. Honing tool and workpiece were assumed as a second-order system, i.e., a spring, mass and damper system in the modeling and analysis.

Peptic Peptide Mapping by HPLC, on Line With Photodiode Array Detection, of a Hemoglobin Hydrolysate Produced at Pilot-Plant Scale from an Ultrafiltration Process

The analysis of a peptic bovine hemoglobin hydrolysate, produced at pilot plant scale, was carried out using two techniques: SE-HPLC and RP-HPLC. Analysis of amino acid composition, second-order derivative spectrometry and FAB mass spectrometry of isolated peptides allowed us to determine the exact positions of these peptides in the sequence of bovine hemoglobin. This, consequently, gave rise to a peptidic map of the hydrolysate. It also revealed, at the same time, some biologically active peptides in the hydrolysate. This information should find use in the potential future application of enzymatic bovine hemoglobin hydrolysate.

Multifractal modeling of fractures in the Lac du Bonnet Batholith, Manitoba

Algorithms to analyze fractures by multifractal modeling are discussed. This approach is more general than fractal modeling. For a small (~0.11 km 2), triangular test area near the Atomic Energy Canada Limited Underground Research Laboratory in the Lac du Bonnet Batholith, it is shown that the surface fractures have a box-counting dimension of 1.977 ± 0.009, which is slightly greater than the second-order mass exponent (= 1.926 ± 0.016). The measure used is total length of exposed surface fractures per cell of variable size. A relatively stable estimate of the multifractal spectrum of fracture intensity was obtained after correcting for local lack of exposure. These results are in agreement with one-dimensional semivariograms estimated for cells measuring 10 m on a side. Approximate isotropy of the measure is demonstrated.

Multifractal modeling and spatial statistics

In general, the multifractal model provides more information about measurements on spatial objects than a fractal model. It also results in mathematical equations for the covariance function and semivariogram in spatial statistics which are determined primarily by the second-order mass exponent. However, these equations can be approximated by power-law relations which are comparable directly to equations based on fractal modeling. The multifractal approach is used to describe the underlying spatial structure of De Wijs 's example of zinc values from a sphalerite-bearing quartz vein near Pulacayo, Bolivia. It is shown that these data are multifractal instead of fractal, and that the second-order mass exponent (=0.979±0.011 for the example) can be used in spatial statistical analysis.

Second-order electron mass dispersion relation at finite temperature. II.

Using the real-time finite-temperature methods the result of a detailed and explicit calculation of the renormalized electron mass to second order in {alpha} in QED is presented. The calculation is in the low-temperature approximation {ital T}{much lt}{ital m}{sub {ital e}} (electron mass) and demonstrates the consistency of the finite-temperature renormalization scheme.

The nuclear self-energy and related quantities in the semiclassical approximation

Abstract By using our recently developed semiclassical model for the imaginary part of the optical potential, we calculate here the polarization and correlation contributions to the real part via the dispersion relation. As underlying nonlocal mean-field potential, the semiclassical Hartree-Fock potential evaluated with the Gogny D1 effective interaction or the Perey-Buck potential is employed. With this full self-energy or second-order mass operator we calculate consistently depths, radial dependence and volume integrals of the single-particle potential, rearrangement energies and effective masses, the momentum distribution, mean free paths of a nucleon in a nucleus, and single-particle level densities. We obtain depths which are in excellent agreement with experiment including the Fermi anomaly: the effective mass exhibits a strong bump at the Fermi and the nuclear surface and the single-particle level density at the Fermi energy is enhanced by 65% yielding almost the correct average experimental value.

A Method for the Calculations of the Nucleon-Nucleus Microscopic Optical Potential

A method for the calculations of the nucleon-nucleus microscopic optical potential based on various kinds of Skyrme force has been introduced. The first- and second-order mass operators in asymmetric nuclear matter have been derived and the real and imaginary parts of the optical potential for finite nuclei have been obtained by applying a local density approximation. The spin-orbit potential has also been obtained approximately. In most cases the expressions are analytical. The calculation results for some sets of Skyrme forces are in good agreement with the-empirical values and experiments.

Semi-microscopic optical potential calculation by the nuclear matter approach

In this paper the semi-microscopic nuclear matter approach has been introduced to calculate the microscopic optical potential. The first- and second-order mass operators in asymmetric nuclear matter have been derived with Skyrme effective interactions and the real and imaginary parts of the optical potential for finite nuclei have been obtained by applying a local density approximation. Five Skyrme interactions II–VI have been used and compared with the experimental data to determine how well these Skyrme interaction function for our purposes. Our results obtained in this simple way are to some extent comparable with those obtained with the “nuclear matter” and “nuclear structure” approaches without adjusting the parameters of the Skyrme interactions.

Higher-order mass formulas in SU(4)

We derive mass formulas among hadrons (1/2/sup +/,3/2/sup +/,O/sup -/,1/sup -/) in SU(4) framework including second-order mass contributions from 84 and 20'' representations. Some hybrid mass relations are obtained by relating second-order parameters. masses of some hadrons are estimated.

Remarks on possible meson symmetries based on outer product groups

A previously discussed model of meson symmetries based on the group SU(3) x SU(3) is updated by (1) giving rigorous proof of a first-order mass formula obtained previously, (2) deriving a second-order mass formula, and (3) extending the whole treatment to SU(4) x SU(4). Tentative assignments are made for the new mesons psi(3100), psi(3700), and psi(4100) in this scheme. (AIP)

The hole spectrum of 12C

The proton hole spectrum of 12C has been investigated in the framework of the continuum shell model with residual interactions. Calculated separation-energy spectra for the reaction 12C(p, 2p) show strong deviation from previous results which were obtained by the Green function method with a second-order mass operator.

Okubo second-order mass formula fromSO(6,1)

The study of the unificationSO(6,1) as a spectrum generating algebra is continued to include baryons in the scheme. Among others, the second-order mass formula of Okubo for the 3/2+ baryon resonances is derived.

Hole states in nuclei and the continuum shell model

The hole spectral function which determines the cross section of direct nucleon removal processes is studied in the framework of the continuum shell model with residual interactions. An expression for the spectral function is derived which covers both the bound and continuous parts of the hole spectrum and allows for an exact inclusion of all correlations (except for continuum-continuum coupling) in a restricted space of shell-model configurations. The shell-model approach is compared to the Green function formulation of the spectral function, and some formal relationships between both formulations are established. The results of previous calculations of the spectral function via a second-order mass operator are discussed in the light of the shell-model formalism.

Perturbation Theory and the Mass Sum Rule for the Baryon Octet

Many dynamical derivations of the Gell-Mann-Okubo mass formula for the baryon octet assume that the symmetry-violating interactions can be treated to first order in perturbation theory. The validity of this assumption is tested by a detailed evaluation of second-order effects. A pole model with no free parameters contributes the major portion of the second-order effect; final-state scattering and other corrections are argued to be small. The second-order mass shifts are found to be 200 MeV or more. Since the second-order mass shifts are as large as the first-order shifts, the conclusion is that derivations of the mass splittings based on first-order perturbation theory must be considered as little more than restatements of the pure group-theoretic derivation.