Investigating the role of cationic vacancy on the MgO (001) defect surface: Embedded cluster models study

Abstract To better understand the flow features of pebble cluster in pebble bed, discharging of the pebble cluster were simulated by DEM. The pebble entangled cluster was composed of eight particles connected by rigid bonds and the simulated cluster models are divided into two types: axisymmetric u-particle and distorted z-particle. The simulation starts with the closed discharge outlet and the bonded clusters with different ID are randomly added from the entrance section. The pebbles fall freely and accumulate freely in the pebble bed. The discharge hole opens after all the pebbles being stationary for a period. Then the pebbles are discharged from the pebble bed under gravity. The discharging process is time-dependent bulk-movement behavior. There is not much mixing between layers on the boundary. The vertical end makes the packing loose, but also intensifies the interaction between particles due to entanglement. Consequently, the discharge features of pebble clusters of different included angles were quantified. The results show that the pebble discharging speeds depend on entanglement angle (α of u-particle and η of z-particle) and discharging outlet diameter. A large included angle may play the role of retarding or inhibiting the discharging flowrate. Therefore, the entanglement of particles component also always plays the key role of retarding the discharge.

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The Role of the Pauli Exclusion Principle in Nuclear Physics Models

Symmetry ◽

10.3390/sym12050738 ◽

2020 ◽

Vol 12 (5) ◽

pp. 738

Author(s):

Josué R. M. Berriel-Aguayo ◽

Peter O. Hess

Keyword(s):

Nuclear Structure ◽

Nuclear Physics ◽

Pauli Exclusion Principle ◽

Cluster Models ◽

Exclusion Principle ◽

Practical Reasons ◽

Algebraic Models ◽

Fermion Systems ◽

Basic Concepts

The Pauli Exclusion Principle (PEP) is one of the most basic concepts in physics, but also the most difficult to implement in many-fermion systems, which are common in nuclear physics. To investigate the consequences of ignoring the PEP, we discuss several algebraic models in nuclear structure physics, in particular cluster models. Sometimes they tend to ignore the Pauli Exclusion Principle for practical reasons, leading to flawed interpretations. Though at first sight there seems to be an agreement to experiment, often it is due to the limited number of states known experimentally. We discuss several models which include or not the PEP, illustrating through their differences the importance of the PEP. This contribution is also a review of recently published results.

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Surface Cluster Models for V2O5 - Studies of the Importance of Local Geometry

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19981355 ◽

1998 ◽

Vol 63 (9) ◽

pp. 1355-1367 ◽

Cited By ~ 3

Author(s):

Małgorzata Witko ◽

Renata Tokarz ◽

Klaus Hermann

Keyword(s):

Boundary Conditions ◽

Cluster Structure ◽

Cluster Models ◽

Geometrical Factor ◽

Local Geometry ◽

Surface Geometry ◽

Hydrogen Atoms ◽

Various Boundary Conditions ◽

Electronic Parameters

Catalytic properties of the vanadium pentoxide (010) surface are discussed based upon semiempirical quantum chemical calculations using cluster models. Special attention is paid to the role of the second layer in discussing the geometrical factor by using the semiempirical ZINDO approach. Local electronic properties near the different surface oxygen sites are analyzed with the help of Mulliken populations and Meyer bond order indices. Different optimization procedures (with various boundary conditions) are performed for diverse V-O clusters modeling one and two layers. Electronic parameters of the clusters are found to be similar for the cluster in the bulk and optimized geometry. The optimized geometry of the cluster remains much closer to the surface geometry when the optimization is done for the whole cluster, excluding the saturated hydrogen atoms. Optimization of the small fragment of the cluster, results in the significant rearrangement of the cluster structure and leads to the "warped" geometry (bridging oxygen as well as vanadium atoms are shifted out of the surface). Two types of boundary conditions assumed during the optimization process lead to similar results, the optimization of all atoms in the cluster (with saturating hydrogen atoms kept frozen) and the same optimization in the presence of the second layer. The presence of the second layer stabilizes the surface geometry. The role of the second layer is also shown in a formation of an oxygen vacancy at the bridging position.

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Role of dactinomycin in the improved survival of children with Wilms' tumor

JAMA ◽

10.1001/jama.195.12.1005 ◽

1966 ◽

Vol 195 (12) ◽

pp. 1005-1009 ◽

Cited By ~ 18

Author(s):

D. J. Fernbach

Keyword(s):

Wilms Tumor

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Role of the allergist in diagnosis and management of patients with uveitis

JAMA ◽

10.1001/jama.195.3.167 ◽

1966 ◽

Vol 195 (3) ◽

pp. 167-172 ◽

Cited By ~ 2

Author(s):

T. E. Van Metre

Keyword(s):

Diagnosis And Management

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The power of norms to sway fused group members

Behavioral and Brain Sciences ◽

10.1017/s0140525x18001644 ◽

2018 ◽

Vol 41 ◽

Cited By ~ 1

Author(s):

Winnifred R. Louis ◽

Craig McGarty ◽

Emma F. Thomas ◽

Catherine E. Amiot ◽

Fathali M. Moghaddam

Keyword(s):

Evolutionary Anthropology ◽

Normative Systems ◽

Violent Extremism ◽

Identity Fusion ◽

Group Members

AbstractWhitehouse adapts insights from evolutionary anthropology to interpret extreme self-sacrifice through the concept of identity fusion. The model neglects the role of normative systems in shaping behaviors, especially in relation to violent extremism. In peaceful groups, increasing fusion will actually decrease extremism. Groups collectively appraise threats and opportunities, actively debate action options, and rarely choose violence toward self or others.

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Elaborating the role of reflection and individual differences in the study of folk-economic beliefs

Behavioral and Brain Sciences ◽

10.1017/s0140525x18000274 ◽

2018 ◽

Vol 41 ◽

Author(s):

Kevin Arceneaux

Keyword(s):

Decision Making ◽

Individual Differences ◽

Cognitive Processes ◽

Evolutionary History ◽

Behavioral Responses ◽

History Of ◽

Economic Beliefs

AbstractIntuitions guide decision-making, and looking to the evolutionary history of humans illuminates why some behavioral responses are more intuitive than others. Yet a place remains for cognitive processes to second-guess intuitive responses – that is, to be reflective – and individual differences abound in automatic, intuitive processing as well.

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The role of affect in feelings of obligation

Behavioral and Brain Sciences ◽

10.1017/s0140525x19002449 ◽

2020 ◽

Vol 43 ◽

Author(s):

Stefen Beeler-Duden ◽

Meltem Yucel ◽

Amrisha Vaish

Keyword(s):

Positive Emotions ◽

The Creation ◽

Sense Of Obligation

Abstract Tomasello offers a compelling account of the emergence of humans’ sense of obligation. We suggest that more needs to be said about the role of affect in the creation of obligations. We also argue that positive emotions such as gratitude evolved to encourage individuals to fulfill cooperative obligations without the negative quality that Tomasello proposes is inherent in obligations.

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Refining our understanding of the “elephant in the room”

Behavioral and Brain Sciences ◽

10.1017/s0140525x20000096 ◽

2020 ◽

Vol 43 ◽

Author(s):

Andrew Whiten

Keyword(s):

Social Cognition ◽

Cultural Evolution ◽

Cognitive Abilities ◽

Critical Factors ◽

Technological Culture

Abstract The authors do the field of cultural evolution a service by exploring the role of non-social cognition in human cumulative technological culture, truly neglected in comparison with socio-cognitive abilities frequently assumed to be the primary drivers. Some specifics of their delineation of the critical factors are problematic, however. I highlight recent chimpanzee–human comparative findings that should help refine such analyses.

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Choosing a Markov blanket

Behavioral and Brain Sciences ◽

10.1017/s0140525x19002632 ◽

2020 ◽

Vol 43 ◽

Author(s):

Thomas Parr

Keyword(s):

Markov Blanket ◽

Target Article ◽

The Relationship

Abstract This commentary focuses upon the relationship between two themes in the target article: the ways in which a Markov blanket may be defined and the role of precision and salience in mediating the interactions between what is internal and external to a system. These each rest upon the different perspectives we might take while “choosing” a Markov blanket.

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