Abstract
Despite various RPA-based approaches being widely used, each has its own advantages and disadvantages that can influence the results. In spite of its several drawbacks, using realistic ...mean-field potential and just small number model-dependent parameter makes TGI-QRPA a very efficient RPA-based approach for investigating dipole responses. This work tests the applicability of the TGI-QRPA approach for investigating dipole excitations through a comparison with the up-to-date, fully self-consistent FAM-QRPA approach and the available experimental data. Take into account the fact FAM-QRPA approach has its own drawbacks, such a comparison will also show how the pros and cons of both models can influence the results. The result obtained here with the TGI-QRPA approach was close to that obtained through the up-to-date FAM-QRPA approach and in some aspects, it better reflected the experimental results in terms of the resonance energy and photo-absorption cross -sections of E1 strength. It can therefore be said that despite not being fully self-consistent, using the realistic mean-field potential (Woods–Saxon), analytically restoring the broken translational and Galilean invariances, and using a only two model parameters make the TGI-QRPA approach an effective tool for investigating dipole excitations, where calculations are performed for the electric dipole responses in deformed
156
Gd,
160
Gd,
166
Er, and
168
Er isotopes.
Abstract
The effect of the polarizations on the collective gyromagnetic ratio (
g
R
) has been investigated in detail using the Rotational Invariant Quasiparticle Phonon Nuclear Model (RI-QPNM). The ...model includes an axially symmetric mean-field potential, monopole pairing, spin-dependent residual interactions, and the restoration forces determined according to Pyatov’s prescription for rotational invariance. The restoration of the rotational symmetry gives a solution at the zero energy associated with the rotational branch of nucleonic motion, allowing us to obtain the
g
R
-factors of the core. The remaining solutions lead to the appearance of configuration mixing in the excitation spectrum of the odd-mass deformed nucleus. The configuration mixing quenches both spin and angular momentum matrix elements and affects the contribution of the odd particle to the
g
R
. It has been demonstrated that the polarization factors associated with the Δ
K
= 1 matrix elements are essential to achieve quantitative agreement with the experimental data. It has also been shown that the general assumption for core polarization, i.e.,
g
s
e
f
f
≈
0.6
g
s
f
r
e
e
,
is insufficient to explain the experimental data.
Chromosome testing strategies, such as preimplantation genetic testing for aneuploidy (PGT-A), improve initial IVF outcomes by avoiding unwitting transfer of aneuploid embryos in morphology-based ...selection practices. Newer technologies have revealed that some embryos may appear to have intermediate whole chromosome (or parts of a chromosome termed segmental) copy number results suggesting trophectoderm mosaicism. An embryo with a trophectoderm mosaic-range result may be the only option for transfer for some patients. Recent data suggest that such mosaic embryos can be transferred without added risk of abnormal birth outcomes but may be associated with increased implantation failure and miscarriage rates, with higher values of mosaicism appearing to be less favourable for producing good outcomes. In this Position Statement, we provide guidance to laboratories, clinics, clinicians and counsellors to assist in discussions on the utility and transfer of mosaic embryos.
E
1 transition properties such as the reduced transition probabilities, excitation energies and photon–absorption cross-sections have been theoretically investigated for
181
Ta nucleus within the ...framework of Translational and Galileo Invariant-Quasiparticle Phonon Nuclear Model (TGI-QPNM). The model Hamiltonian includes the single-particle and the isovector dipole–dipole interaction terms along with the restoration forces. The strength of the isovector dipole–dipole interaction has been chosen to be
χ
=
500
/
A
5
/
3
M
e
V
·
f
m
-
2
. Theoretical calculations show that in addition to the
M
1 excitations, there is considerable amount of
E
1 transitions especially between 2.6–3 MeV, which gives remarkable contribution to the fragmentation in the low-energy region of the dipole spectrum. Thus, the agreement between theory and experiment in terms of the fragmentation increases. Furthermore, the photon–absorption cross-sections in the Pigmy Dipole Resonance (PDR) region below the neutron separation energy (
S
n
) is compatible with experimental data.
•STR model accounts for anisotropy of normal Reynolds stresses.•STR model predicts Oxygen profiles in Cz 8″ Silicon crystals with 10% accuracy.•Computer simulation predicted the Oxygen reduction by ...13% in Cz Si crystal growth.
Modeling of oxygen transport during Czochralski (Cz) silicon crystal growth still is a big challenge due to oxygen evacuation from the melt free surface, affected by strong anisotropy of turbulent mass transport. To predict the crystal oxygen concentration and crystallization front geometry with reasonable accuracy usually a 3D unsteady LES or DNS approach is required which demands significant computation resources and time. We present a new steady turbulence model using the extended hypothesis for modeling the Reynolds stress tensor, which accounts for different mechanisms of Reynolds stresses anisotropy and can be used in fast 2D engineering calculations. Several 8″ silicon crystals were grown in EKZ 3500 furnace with varying operating parameters. Wafers have been cut from different parts of the crystals and analyzed using the Fourier-transform infrared spectroscopy (FTIR) for oxygen concentration in facilities of Fraunhofer CSP and iTechSolar. The comparison between experimental and calculated results, which include oxygen concentration and interface deflection, is discussed in details. Time-averaged Reynolds stress tensor components as well as the turbulent heat fluxes components are compared between unsteady LES and steady RANS approaches.
It was previously shown that more than half of the human oocytes obtained from IVF patients of advanced reproductive age are aneuploid, due to meiosis I and meiosis II errors. The present paper ...further confirms that 61.8% of the oocytes tested by fluorescent probes specific for chromosomes 13, 16, 18, 21 and 22 are abnormal, representing predominantly chromatid errors, which are the major source of aneuploidy in the resulting embryos. Almost half of the oocytes with meiosis I errors (49.3%) are prone to sequential meiosis II errors, which may lead to aneuploidy rescue in 30.8% of the cases. Half of the detected aneuploidies (49.8%) are of complex nature with involvement of two or more chromosomes, or the same chromosome in both meiotic divisions. The aneuploidy rates for individual chromosomes are different, with a higher prevalence of chromosome 21 and 22 errors. The origin of aneuploidy for the individual chromosomes is also not random, with chromosome 16 and 22 errors originating more frequently in meiosis II, and chromosome 18, 13 and 21 errors in meiosis I. There is an age dependence not only for the overall frequency of aneuploidies, but also for each chromosome error, aneuploidies originating from meiosis I, meiosis II, and both meiosis I and meiosis II errors, as well as for different types of aneuploidies. The data further suggest the practical relevance of oocyte aneuploidy testing for detection and avoidance from transfer of the embryos deriving from aneuploid oocytes, which should contribute significantly to the pregnancy outcomes of IVF patients of advanced reproduction age.
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