2,318 research outputs found
Theoretical studies on structural and decay properties of superheavy nuclei
In this manuscript, we analyze the structural properties of
superheavy nuclei in the mass range of 284 A 375 within the
framework of deformed relativistic mean field theory (RMF) and calculate the
binding energy, radii, quadrupole deformation parameter, separation energies
and density profile. Further, a competition between possible decay modes such
as decay, decay and spontaneous fission (SF) of the isotopic
chain of superheavy nuclei under study is systematically analyzed
within self-consistent relativistic mean field model. Moreover, our analysis
confirmed that decay is restricted within the mass range 284 A
296 and thus being the dominant decay channel in this mass range.
However, for the mass range 297 A 375 the nuclei are unable to
survive fission and hence SF is the principal mode of decay for these isotopes.
There is no possibility of decay for the considered isotopic chain. In
addition, we forecasted the mode of decay 119 as one chain
from 119 and 119, two consistent chains from
119 and 119, three consistent chains from 119
and 119, four consistent alpha chains from 119, six consistent
alpha chains from 119. Also from our analysis we inferred that for
the isotopes Bh both decay and SF are equally
competent and can decay via either of these two modes. Thus, such studies can
be of great significance to the experimentalists in very near future for
synthesizing superheavy nuclei.Comment: 14 pages, 6 figures. arXiv admin note: text overlap with
arXiv:1611.00232, arXiv:1704.0315
Structural and decay properties of superheavy nuclei
In this paper, we analyze the structural properties of and
superheavy nuclei within the ambit of axially deformed relativistic mean-field
framework with NL parametrization and calculate the total binding
energies, radii, quadrupole deformation parameter, separation energies, density
distributions. We also investigate the phenomenon of shape coexistence by
performing the calculations for prolate, oblate and spherical configurations.
For clear presentation of nucleon distributions, the two-dimensional contour
representation of individual nucleon density and total matter density has been
made. Further, a competition between possible decay modes such as
-decay, -decay and spontaneous fission of the isotopic chain of
superheavy nuclei with within the range 312 A 392 and 318
A 398 for is systematically analyzed within self-consistent
relativistic mean field model. From our analysis, we inferred that the
-decay and spontaneous fission are the principal modes of decay in
majority of the isotopes of superheavy nuclei under investigation apart from
decay as dominant mode of decay in isotopes.Comment: 16 pages, 10 figures , 8 table
Seasonality of cognitive function in the general population:the Rotterdam Study
Seasonal variation in cognitive function and underlying cerebral hemodynamics in humans has been suggested, but not consistently shown in previous studies. We assessed cognitive function in 10,276 participants from the population-based Rotterdam Study, aged 45 years and older without dementia, at baseline and at subsequent visits between 1999 and 2016. Seasonality of five cognitive test scores and of a summary measure of global cognition were determined, as well as of brain perfusion. Using linkage with medical records, we also examined whether a seasonal variation was present in clinical diagnoses of dementia. We found a seasonal variation of global cognition (0.05 standard deviations [95% confidence interval: 0.02–0.08]), the Stroop reading task, the Purdue Pegboard test, and of the delayed world learning test, with the best performance in summer months. In line with these findings, there were fewer dementia diagnoses of dementia in spring and summer than in winter and fall. We found no seasonal variation in brain perfusion. These findings support seasonality of cognition, albeit not explained by brain perfusion. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11357-021-00485-0
Formation of Medium-Heavy Elements in Rapid Neutron Capture Process
We predict the neutron drip-line and simulate the r—process path for Cu — Sn, based on the calculation of binding energy in the frame-work of relativistic and non-relativistic mean field formalisms. We also compare the quadrupole deformation parameterβ2, and one neutron separation energy Sn of these isotopic series with the results of finite range droplet model (FRDM) prediction. the results produced by RMF and ShF are comparable to each other and also agreeable with the FRDM model
Skin autofluorescence, reflecting accumulation of advanced glycation end products, and the risk of dementia in a population-based cohort
Conditions such as hyperglycemia and oxidative stress lead to the formation of advanced glycation end products (AGEs), which are harmful compounds that have been implicated in dementia. Within the Rotterdam Study, we measured skin AGEs as skin autofluorescence, reflecting long-term accumulation of AGEs, and determined their association with the risk of dementia and with brain magnetic resonance imaging (MRI) measures. Skin autofluorescence was measured between 2013 and 2016 in 2922 participants without dementia. Of these, 1504 also underwent brain MRI, on which measures of brain atrophy and cerebral small vessel disease were assessed. All participants were followed for the incidence of dementia until 2020. Of 2922 participants (mean age 72.6 years, 57% women), 123 developed dementia. Higher skin autofluorescence (per standard deviation) was associated with an increased risk of dementia (hazard ratio 1.21 [95% confidence interval 1.01–1.46]) and Alzheimer’s disease (1.19 [0.97–1.47]), independently of age and other studied potential confounders. Stronger effects were seen in apolipoprotein E (APOE) ε4 carriers (1.34 [0.98–1.82]) and in participants with diabetes (1.35 [0.94–1.94]). Participants with higher skin autofluorescence levels also had smaller total brain volumes and smaller hippocampus volumes on MRI, and they had more often lacunes. These results suggest that AGEs may be involved in dementia pathophysiology.</p
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