Phenomenological analysis of ΔI = 4 bifurcation and identical superdeformed bands

2021 ◽  
pp. 2150012
Author(s):  
Anshul Dadwal
Keyword(s):  
Empirical Evidence ◽  
Systematic Study ◽  
Mass Region ◽  
Phenomenological Analysis ◽  
Rotational Energy ◽  
Free Parameters ◽  
Superdeformed Bands ◽  
First Time ◽  
Fluctuation Model

For the first time, a systematic study of identical superdeformed (SD) bands in [Formula: see text] mass region is made, where [Formula: see text] bifurcation is present. Four pairs of identical SD bands viz. [Formula: see text] and [Formula: see text] of [Formula: see text] mass region and [Formula: see text] and [Formula: see text] of [Formula: see text] mass region have been systematically studied. The present systematic study provides the universal description of the identical SD bands in various mass regions. We presented the empirical evidence of a similar structure of identical SD bands in various mass regions. For this purpose, we have used various rotational energy formulae. The free parameters are extracted from four identical SD bands. The [Formula: see text] bifurcation in identical SD bands is calculated from shape fluctuation formulae. For the first time, this shape fluctuation model is employed to calculate the [Formula: see text] bifurcation, making it an alternate powerful tool to study SD bands of various mass regions.

SYSTEMATIC STUDY OF NUCLEAR SOFTNESS OF SUPERDEFORMED BANDS IN A = 190 MASS REGION

2013 ◽  
Vol 22 (08) ◽  
pp. 1350053 ◽  
Author(s):  
NEHA SHARMA ◽  
H. M. MITTAL
Keyword(s):  
Systematic Study ◽  
Gamma Ray ◽  
Neutron Number ◽  
Mass Region ◽  
Energy Ratio ◽  
Softness Parameter ◽  
Superdeformed Bands ◽  
Parameter Values ◽  
First Time ◽  
Valence Proton

A four parameter formula has been applied to obtain the nuclear softness parameter (σ) for all the superdeformed (SD) bands observed in A = 190 mass region. The nuclear softness parameter values of most of the SD bands are found to be smaller than those of the normal deformed bands, implying more rigidity. The results of this work includes the variation of nuclear softness parameter against the gamma ray energy ratio R(I) = Eγ(I→(I-2))/Eγ((I-2)→(I-4)) of SD bands in A = 190 mass region. The variation of R(I) and the nuclear softness parameter of these SD bands are studied with the product of valence proton and neutron numbers (NpNn). The systematics also includes the variation of σ with the neutron number N. It is also found that the value of softness parameter of signature partner SD bands observed in A = 190 mass region is also the same. We present for the first time the study of softness parameter of SD bands with NpNn scheme.

Examination of phenomenological formulae in superdeformed bands of A ∼ 190,150 mass regions

2020 ◽  
Vol 29 (09) ◽  
pp. 2050081
Author(s):  
Monica Karday ◽  
Anshul Dadwal ◽  
H. M. Mittal
Keyword(s):  
Careful Analysis ◽  
Exponential Model ◽  
Mass Region ◽  
Rotational Energy ◽  
Band Head ◽  
General Nature ◽  
Model Parameters ◽  
Softness Parameter ◽  
Superdeformed Bands ◽  
Gap Parameter

The rotational energy formulae viz. VMI model, ab-formula, Harris [Formula: see text] expansion, Exponential model with pairing attenuation and Nuclear softness formula are employed to the superdeformed bands of [Formula: see text] and [Formula: see text] mass regions in order to test the validity of various rotational energy formulae in describing the general nature of superdeformed bands. These formulae are used to deduce the band-head spins of the nine superdeformed bands in [Formula: see text] mass region and two superdeformed bands of [Formula: see text] mass region. The band-head spins of these superdeformed bands have been established experimentally and hence they prove to be excellent candidates to examine the adequacy of rotational energy formulae in superdeformed bands. The least-squares fitting of [Formula: see text]-transition energies is performed to calculate the model parameters such as the band-head moment of inertia, the effective pairing gap parameter and the softness parameter, and a careful analysis of these parameters is made. For the first time, we have performed a systematic study of the rotational energy formulae to establish which formula gives the best estimate of spin in [Formula: see text] mass regions.

scholarly journals Plebański–Demiański solution of general relativity and its expressions quadratic and cubic in curvature: Analogies to electromagnetism

2015 ◽  
Vol 24 (10) ◽  
pp. 1550079 ◽  
Author(s):  
Jens Boos
Keyword(s):  
General Relativity ◽  
Electromagnetic Field ◽  
General Type ◽  
Coordinate Systems ◽  
Irreducible Decomposition ◽  
Asymptotically Flat ◽  
Type D ◽  
Curvature Invariants ◽  
Free Parameters ◽  
First Time

Analogies between gravitation and electromagnetism have been known since the 1950s. Here, we examine a fairly general type D solution — the exact seven parameter solution of Plebański–Demiański (PD) — to demonstrate these analogies for a physically meaningful spacetime. The two quadratic curvature invariants B2 - E2 and E⋅B are evaluated analytically. In the asymptotically flat case, the leading terms of E and B can be interpreted as gravitoelectric mass and gravitoelectric current of the PD solution, respectively, if there are no gravitomagnetic monopoles present. Furthermore, the square of the Bel–Robinson tensor reads (B2 + E2)2 for the PD solution, reminiscent of the square of the energy density in electrodynamics. By analogy to the energy–momentum 3-form of the electromagnetic field, we provide an alternative way to derive the recently introduced Bel–Robinson 3-form, from which the Bel–Robinson tensor can be calculated. We also determine the Kummer tensor, a tensor cubic in curvature, for a general type D solution for the first time, and calculate the pieces of its irreducible decomposition. The calculations are carried out in two coordinate systems: In the original polynomial PD coordinates and in a modified Boyer–Lindquist-like version introduced by Griffiths and Podolský (GP) allowing for a more straightforward physical interpretation of the free parameters.

How is the Balance of a Forecast Ensemble Affected by Adaptive and Nonadaptive Localization Schemes?

2015 ◽  
Vol 143 (9) ◽  
pp. 3680-3699 ◽  
Author(s):  
Ross N. Bannister
Keyword(s):  
Forecast Error ◽  
Covariance Matrices ◽  
Error Statistics ◽  
Error Covariance ◽  
Localization Scheme ◽  
Adaptive Schemes ◽  
Convective Scale ◽  
Free Parameters ◽  
Hydrostatic Balance ◽  
First Time

Abstract This paper investigates the effect on balance of a number of Schur product–type localization schemes that have been designed with the primary function of reducing spurious far-field correlations in forecast error statistics. The localization schemes studied comprise a nonadaptive scheme (where the moderation matrix is decomposed in a spectral basis), and two adaptive schemes: a simplified version of Smoothed Ensemble Correlations Raised to a Power (SENCORP) and Ensemble Correlations Raised to a Power (ECO-RAP). The paper shows, the author believes for the first time, how the degree of balance (geostrophic and hydrostatic) implied by the error covariance matrices localized by these schemes can be diagnosed. Here it is considered that an effective localization scheme is one that reduces spurious correlations adequately, but also minimizes disruption of balance (where the “correct” degree of balance or imbalance is assumed to be possessed by the unlocalized ensemble). By varying free parameters that describe each scheme (e.g., the degree of truncation in the schemes that use the spectral basis, the “order” of each scheme, and the degree of ensemble smoothing), it is found that a particular configuration of the ECO-RAP scheme is best suited to the convective-scale system studied. According to the diagnostics this ECO-RAP configuration still weakens geostrophic and hydrostatic balance, but overall this is less so than for other schemes.

A systematic study on the intradiffusion and structure of N,N-dimethylformamide–water mixtures: by experiment and molecular dynamics simulation

RSC Advances ◽  
2016 ◽  
Vol 6 (88) ◽  
pp. 85603-85611 ◽  
Author(s):  
Jinyang Wang ◽  
Wei Gao ◽  
Haimin Zhong ◽  
Canjian Liang ◽  
Xiaojuan Chen ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Systematic Study ◽  
Dynamics Simulation ◽  
Pgse Nmr ◽  
First Time

Intradiffusion coefficients ofN,N-dimethylformamide (DDMF) and water (DW) in their mixtures were measured as a function of temperature, pressure and composition for the first time using the PGSE-NMR technique.

Cognitive control

2021 ◽  
pp. 93-116
Author(s):  
John Toner ◽  
Barbara Gail Montero ◽  
Aidan Moran
Keyword(s):  
Executive Function ◽  
Problem Solving ◽  
Cognitive Control ◽  
Empirical Evidence ◽  
Skill Acquisition ◽  
Mental Representations ◽  
Phenomenological Analysis ◽  
Cognitive Responses ◽  
Expert Performance ◽  
On Line

What role might intuition and deliberation play during the performance of well-learned skills? Dreyfus and Dreyfus’ (1986) influential phenomenological analysis of skill-acquisition proposes that expert performance is guided by non-cognitive responses which are fast, effortless, and intuitive in nature. Although Dreyfus and Dreyfus (1986) recognize that, on occasions (e.g. when performance goes awry for some reason), a form of ‘detached deliberative rationality’ may be used by experts to improve their performance, they see no role for calculative problem solving or deliberation (i.e. drawing on rules or mental representations) when performance is going well. The current chapter counters this argument by drawing on empirical evidence and phenomenological description to argue that skilled performers use cognitive control (an executive function) across a range of sporting situations (i.e. in training, pre-performance routines, on-line skill execution) in order to maintain and enhance performance proficiency.

scholarly journals ATOP THE KADMEIA: MYCENAEAN ROOF TILES FROM THEBES IN CONTEXT

2020 ◽  
Vol 115 ◽  
pp. 175-245
Author(s):  
Vassilis L. Aravantinos ◽  
Ioannis Fappas ◽  
Yannis Galanakis
Keyword(s):  
Bronze Age ◽  
Fourteenth Century ◽  
Systematic Study ◽  
Late Bronze Age ◽  
Similar Material ◽  
Widespread Distribution ◽  
The Past ◽  
North East ◽  
The North ◽  
First Time

Questions were raised in the past regarding the use of Mycenaean tiles as ‘roof tiles’ on the basis of the small numbers of them recovered in excavations and their overall scarcity in Mycenaean domestic contexts. The investigation of the Theodorou plot in 2008 in the southern part of the Kadmeia hill at Thebes yielded the single and, so far, largest known assemblage per square metre of Mycenaean tiles from a well-documented excavation. This material allows, for the first time convincingly, to identify the existence of a Mycenaean tiled roof. This paper presents the results of our work on the Theodorou tiles, placing emphasis on their construction, form and modes of production, offering the most systematic study of Mycenaean tiles to date. It also revisits contexts of discovery of similar material from excavations across Thebes. Popular as tiles might have been in Boeotia, and despite their spatially widespread attestation, their use in Aegean Late Bronze Age architecture appears, on the whole, irregular with central Greece and the north-east Peloponnese being the regions with the most sites known to have yielded such objects. Mycenaean roof tiles date mostly from the mid- and late fourteenth century bc to the twelfth century bc. A study of their construction, form, production and contexts suggests that their role, apart from adding extra insulation, might have been one of signposting certain buildings in the landscape. We also present the idea that Mycenaean tile-making was guided by a particular conventional knowledge which was largely influenced by ceramic-related technologies (pottery- and drain-making). While production of roof tiles might have been palace-instigated to begin with, it does not appear to have been strictly controlled. This approach to Mycenaean tile-making may also help explain their uneven (in terms of intensity of use) yet widespread distribution.

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