M1 Moments Research Articles

Investigation of the frequency of free vibrations for pipelines with different physical and mechanical properties of the material

This paper raises the question of a new approach to the dynamic calculation of thin-walled underground pipelines of large diameter, which is based on the application of the Vlasov-Novozhilov half-time theory of medium-bend shells, which ignores the M1 moments that bend the cylindrical shell in the longitudinal direction, since they are much smaller than the M2 moments that bend it in the transverse direction. The resolving equation for this approach is a homogeneous 4th-order differential equation that uses two boundary conditions at each end to solve it. The resulting equation takes into account the parameter of the longitudinal force, the value of the internal pressure, the coefficient of elastic resistance of the soil, the parameter of thinness, as well as the attached mass of the soil. Based on the data obtained from the derived formulas, the frequency characteristics of thin-walled underground pipelines of large diameter with different physical and mechanical properties are determined depending on the length of the element, as well as ground conditions. It is established that the minimum frequencies for the shell form of vibrations in various ground conditions are realized only for steel pipes, and for polyethylene and fiberglass pipes, depending on the coefficient of elastic resistance of the soil, they can be realized both in the rod and shell form. At the same time, using a dynamic stability criterion, derived expressions to determine the critical external pressure, taking into account the pipe length and the number of half waves in the cross section in which there is a constructive denial of the pipeline. Based on this expression, a formula for determining the critical depth of laying for thin-walled pipelines is obtained.

Nephrocalcinosis induced by hyperoxaluria in rats

To investigate nephrocalcinosis due to hyperoxaluria induced by two different inducing agents in rats. Forty Sprague-Dawley male rats were randomly distributed into four groups: Group 1 (Clinical control, n = 10); Group 2 (0.5% Ethylene Glycol + Vitamin D3, n = 10); Group 3 (1.25% Ethylene Glycol, n = 10); and Group 4 (5%Hydroxy L-proline, n = 10). Five animals from each group were euthanized after one week of follow-up (M1 Moment) and the remaining, after four weeks (M2 Moment). All animals underwent 24h urine dosages of calcium, oxalate, uric acid, citrate and serum creatinine. Histology and histomorphometric analyses were performed using Image J program in the hematoxylin-eosin stains. Calcium deposits in the renal parenchyma were quantified by PIXE technique (Proton Induced X-Ray Emission). 24h urinary parameters did not show any significant variations after 28 days of experiment except by hyperoxaluria that was significantly higher in Group 3. Histomorphometric analyses showed a significantly higher nephrocalcinosis in Group 2 (p<0.01). The calcium deposits in the renal parenchyma were 10 and 100 times higher in Group 2 in comparison to other groups in the M1 and M2 moments, respectively. The Group 2 (vitamin D3+Ethylene Glycol 0.5%) was the best model to induce nephrocalcinosis in rats after 28 days.

Microscopic description of nuclei in the middle of the pf-shell by a shell-model calculation with G-matrix interaction

Energy levels and electromagnetic properties of 24 nuclides with N = 28–30 are studied in terms of a large-scale shell-model calculation, which contains no newly adjusted parameters. The Kuo-Brown G-matrix interaction is shown to reproduce energy levels of 205 low-lying states of all these nuclei. We evaluate effective charges by incorporating the core-polarization effects caused by the coupling to GQR's. We then compute E2 moments and transition probabilities. The M1 moments and transition rates are calculated by quoting the effective g-factors of Towner, which are obtained by taking into account the meson-exchange and the core-polarization mechanisms. By this microscopic calculation most of the E2 properties and the magnetic moments are reproduced. Although there are agreements and disagreements in the M1 transition rates, the general tendency is reproduced. The (e,e ) ́ and (p,p ) ́ excitation from the ground state to some low-lying 2 + states is also discussed.

Variational approach to magnetic dipole core polarization: Applications to moments and transitions

A variational approach to magnetic dipole core polarization is discussed which goes beyond the usual perturbative treatment and takes the coupling between the collective magnetic dipole state and single particle states into account. Using various spin-dependent effective interactions simple expressions for corrections to the g-factors of the free nucleons are derived. The effect of the coupling of the collective M1 state in 48Ca, 90Zr and 208Pb to single particle M1 moments and transitions in the neighbouring A=48±1, 90±1 and 208±1 nuclei, respectively, is pointed out.

On the role of the Δ resonance in the effective spin-dependent moments of nuclei

A simple estimate is made of the effect of the Δ resonance on isovector M1 and Gamow-Teller moments in nuclei. The ratio of matrix elements for nucleon-Δ to nucleon-nucleon transitions are based on the quark model. The observed M1 moments and energies of GT giant resonances yield consistent values for the strength of the interactions.

1 + state and effective g-factor

The effects of nuclear field r 2(Y 2 σ 1) 1 υ on magnetic properties of single-particle states in odd- A nuclei ( 208±1Pb) are considered. The coupling constant associated with this type of field is estimated by an argument that realtes it to the coupling constant for the field ( γ 0 σ 1) 1 υ . The effects of including the r 2(Y 2 σ 1) 1 υ field on the M1 moments and transitions are estimated.

The contribution to M1 moments from particle-vibration (λ π) coupling with λπ≠ 1 +

A systematic survey of the possible contributions to the magnetic-dipole matrix elements from the core-excitation modes with λ π ≠ 1 + is presented for the single-particle states in the 208Pb region.

Resonance processes and nuclear excitation in muonic 205Tl

The L and K X-rays of muonic 205Tl have been measured with an enriched (99.8 %) 205Tl target. Two sets of resonance processes were included in the analysis, which led to satisfactory fits to the experimental spectra, and explain the anomalous intensity ratios between the fine structure components of the muonic L and K X-rays. At the same time, the M1 hyperfine structure constants, which show the finite distribution of the nuclear M1 moment, were determined. Also determined were the static nuclear E2 and M1 moments of the excited states.

Nuclear excitation in muonic 209Bi

The hyperfine spectra of muonic L and K X-rays of 209Bi have been reanalyzed by taking into account the resonance processes and the observed isomer shifts in addition to the M1 and the E2 interaction. The M1 and E2 hyperfine structure constants of the 1s, 2p and 3d muonic states and the nuclear static moments of the excited states 15 2 + and 9 2 + are determined from the best fits to the experimental spectra. The hfs constants and the M1 moments are in good agreement with theoretical predictions from the core excitation model. The quadrupole moment of the ground state remains to be 20% higher than that determined by the atomic beam method. A plausible interpretation is that this discrepancy might be due to the deformation of the lead core.

The resonance process and the intensity anomaly in muonic 127I

The muonic N, M, L and K X-rays of 127I have been measured and analyzed. A resonance process involving the muonic 2p levels and the nuclear ground and first excited states was included in the analysis. A satisfactory fit to the experimental spectra was achieved, at the same time, the parameters of the Fermi charge distribution, the M1 and the E2 hyperfine structure constants and the M1 and the E2 transition moments were determined. The M1 hyperfine structure constants and the M1 transition moment showed the effects of the finite distribution of the static and the transition M1 moments, while the E2 hyperfine structure constants offered an independent determination of the electric quadrupole moment.