2,963 research outputs found
Violation of the Ikeda sum rule and the self-consistency in the renormalized quasiparticle random phase approximation and the nuclear double-beta decay
The effect of the inclusion of ground state correlations into the QRPA
equation of motion for the two-neutrino double beta () decay
is carefully analyzed. The resulting model, called renormalized QRPA (RQRPA),
does not collapse near the physical value of the nuclear force strength in the
particle-particle channel, as happens with the ordinary QRPA. Still, the
transition amplitude is only slightly less sensitive on
this parameter in the RQRPA than that in the plain QRPA. It is argued that this
fact reveals once more that the characteristic behaviour of the
transition amplitude within the QRPA is not an artifact of
the model, but a consequence of the partial restoration of the spin-isospin
symmetry. It is shown that the price paid for bypassing the collapse in
the RQRPA is the violation of the Ikeda sum rule.Comment: 16 pages, latex, 3 postscript figure
Kvazičestična aproksimacija nasumnih faza bez urušavanja za dvojni beta raspad
We show how the longstanding problem of the collapse of the charge–exchange QRPA near the physical value of the force strength can be circumvented. This is done by including the effect of ground state correlations into the QRPA equations of motion. The corresponding formalism, called renormalized QRPA, is briefly outlined and its consequences are discussed in the framework of a schematic model for the two-neutrino double beta decay in the 100Mo → 100Ru system. The question of the conservation of the Ikeda sum rule is also addressed within the new formalism.Pokazuje se kako se može izbjeći tvrdokorni problem urušavanja kvazičestične aproksimacije nasumnih faza (QRPA) s nabojskom izmjenom za realne vrijednosti jakosti sila. To se postiže uključivanjem korelacije u osnovnom stanju u jednadžbe stanja QRPA. Raspravljaju se rezultati za shematski model dvoneutrinskog dvojnog beta raspada 100Mo → 100Ru. U okviru ovog formalizma također se raspravlja pitanje Ikedinog zbrojnog pravila
Kvazičestična aproksimacija nasumnih faza bez urušavanja za dvojni beta raspad
We show how the longstanding problem of the collapse of the charge–exchange QRPA near the physical value of the force strength can be circumvented. This is done by including the effect of ground state correlations into the QRPA equations of motion. The corresponding formalism, called renormalized QRPA, is briefly outlined and its consequences are discussed in the framework of a schematic model for the two-neutrino double beta decay in the 100Mo → 100Ru system. The question of the conservation of the Ikeda sum rule is also addressed within the new formalism.Pokazuje se kako se može izbjeći tvrdokorni problem urušavanja kvazičestične aproksimacije nasumnih faza (QRPA) s nabojskom izmjenom za realne vrijednosti jakosti sila. To se postiže uključivanjem korelacije u osnovnom stanju u jednadžbe stanja QRPA. Raspravljaju se rezultati za shematski model dvoneutrinskog dvojnog beta raspada 100Mo → 100Ru. U okviru ovog formalizma također se raspravlja pitanje Ikedinog zbrojnog pravila
Testing Reliability of Biophilic Design Matrix Within Urban Residential Playrooms
Playtime in urban cities has become an indoor activity for children due to limited access to natural outdoor environments. This product of urbanization makes the case for the introduction of biophilic design. However, playrooms are often neglected as a possibility in designing a natural space indoors. Interior designers and other specialists lack a reliable tool to identify and incorporate biophilic features into the design of these indoor environments in urban settings. The Biophilic Interior Design Matrix (BID-M) developed by McGee and Marshall-Baker quantifies 52 of Kellert’s biophilic design attributes to assess their presence and absence within interior spaces. We expanded its use by testing the matrix in a new type of space, urban playrooms, and coded images of 45 children’s playrooms within Manhattan residential buildings in New York City, including assessing a larger sample and reliability rate compared to McGee and Marshall-Baker’s research. Inter-rater reliability of the overall design matrix and individual matrix items was measured with percent agreement and free-marginal multirater kappa. Reliability testing showed overall good reliability of the overall design matrix. Several matrix items had low reliability between raters. Our findings show that the BID-M needs to be modified to better assess urban interior spaces for children
Enabling fast power integrity transient analysis through parameterized small-signal macromodels
In this paper, we present an automated strategy for extracting behavioral small-signal macromodels of biased nonlinear circuit blocks. We discuss in detail the case study of a Low DropOut (LDO) voltage regulator, which is an essential part of the power distribution network in electronic systems. We derive a compact yet accurate surrogate model of the LDO, which enables fast transient power integrity simulations, including all parasitics due to the specific layout of the LDO realization. The model is parameterized through its DC input voltage and its output current and is thus available as a SPICE netlist. Numerical experiments show that a speedup up to 700X is achieved when replacing the extracted post-layout netlist with the surrogate model, with practically no loss in accuracy
Coherence lifetimes of excitations in an atomic condensate due to the thin spectrum
We study the quantum coherence properties of a finite sized atomic condensate
using a toy-model and the thin spectrum model formalism. The decoherence time
for a condensate in the ground state, nominally taken as a variational symmetry
breaking state, is investigated for both zero and finite temperatures. We also
consider the lifetimes for Bogoliubov quasi-particle excitations, and contrast
them to the observability window determined by the ground state coherence time.
The lifetimes are shown to exhibit a general characteristic dependence on the
temperature, determined by the thin spectrum accompanying the spontaneous
symmetry breaking ground state
Dissipative collisions in O + Al at E=116 MeV
The inclusive energy distributions of fragments (3Z7) emitted in
the reaction O + Al at 116 MeV have been measured in
the angular range = 15 - 115. A non-linear
optimisation procedure using multiple Gaussian distribution functions has been
proposed to extract the fusion-fission and deep inelastic components of the
fragment emission from the experimental data. The angular distributions of the
fragments, thus obtained, from the deep inelastic component are found to fall
off faster than those from the fusion-fission component, indicating shorter
life times of the emitting di-nuclear systems. The life times of the
intermediate di-nuclear configurations have been estimated using a diffractive
Regge-pole model. The life times thus extracted (
Sec.) are found to decrease with the increase in the fragment charge. Optimum
Q-values are also found to increase with increasing charge transfer i.e. with
the decrease in fragment charge.Comment: 9 pages, 4 figures, 1 tabl
BRS 184 soybean.
BRS 184 is a soybean cultivar developed by Embrapa Soybean for sowing in Parana State. It flowers and reaches maturity 53 and 121 days after germination and yields 3,210 kg/ha. BRS 184 is resistant to stem canker, frog-eye leaf spot, bacterial pustule and moderately resistant to powdery mildew
BRS 185 soybean.
BRS 185 is a soybean cultivar developed by Embrapa Soybean for sowing in Parana State. It flowers and reaches maturity 53 and 121 days after germination and yields 3,090 kg/ha. BRS 185 is resistant to stem canker, frog-eye leaf spot, bacterial pustule and moderately resistant to powdery mildew.Autoria: DOMITTI [i.e. DOMIT], L. A
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