Generalized thermomechanics with dual internal variables

Wave propagation in materials with embedded two different microstructures is considered. Each microstructure is characterized by its own length scale. The dual internal variables approach is adopted yielding in a Mindlin-type model including both microstructures. Equations of motion for microstructures are coupled with the balance of linear momentum for the macromotion, but not coupled with each other. Corresponding dispersion curves are provided and scale separation is pointed out.

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Do Event-Related Brain Potentials Reflect Mental (Cognitive) Operations?

Journal of Psychophysiology ◽

10.1027//0269-8803.16.3.129 ◽

2002 ◽

Vol 16 (3) ◽

pp. 129-149 ◽

Cited By ~ 13

Author(s):

Boris Kotchoubey

Keyword(s):

Cognitive Processes ◽

Point Of View ◽

Internal Variables ◽

Brain Potentials ◽

Cognitive Operations ◽

External Variables ◽

Series Of Experiments ◽

Mental Operations ◽

A Chain ◽

Processing Mechanisms

Abstract Most cognitive psychophysiological studies assume (1) that there is a chain of (partially overlapping) cognitive processes (processing stages, mechanisms, operators) leading from stimulus to response, and (2) that components of event-related brain potentials (ERPs) may be regarded as manifestations of these processing stages. What is usually discussed is which particular processing mechanisms are related to some particular component, but not whether such a relationship exists at all. Alternatively, from the point of view of noncognitive (e. g., “naturalistic”) theories of perception ERP components might be conceived of as correlates of extraction of the information from the experimental environment. In a series of experiments, the author attempted to separate these two accounts, i. e., internal variables like mental operations or cognitive parameters versus external variables like information content of stimulation. Whenever this separation could be performed, the latter factor proved to significantly affect ERP amplitudes, whereas the former did not. These data indicate that ERPs cannot be unequivocally linked to processing mechanisms postulated by cognitive models of perception. Therefore, they cannot be regarded as support for these models.

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Prevalence of imaginary companions among Chinese children aged 4 to 6 years

Social Behavior and Personality An International Journal ◽

10.2224/sbp.8845 ◽

2020 ◽

Vol 48 (3) ◽

pp. 1-11

Author(s):

Qiyi Lin ◽

Nan Zhou ◽

Hong Fu

Keyword(s):

Age Groups ◽

Income Group ◽

Internal Variables ◽

Annual Income ◽

Imaginary Companions ◽

Socioeconomic Environment ◽

Imaginary Play ◽

Relationship Qualities ◽

Different Dimensions ◽

The Relationship

We investigated the prevalence of Chinese children's imaginary companions (ICs) and the internal variables of IC types (personified object or invisible friend) and child–IC relationship qualities (egalitarian or hierarchical child–IC relationship). Participants were 266 children aged 4 to 6 years. Only in the 5-year-old group was the proportion of children with ICs significantly higher among girls than among boys, implying that the relationship between gender and IC was not consistent across age groups. Children from families in the highest annual income group engaged in more IC play than did children from families in the lowest annual income group, indicating a relationship between family socioeconomic environment and children's imaginary play. IC types were not associated with child–IC relationship qualities in any of the age groups, implying that these qualities may represent different dimensions of IC play as early as 4 years old.

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Internal variables used for describing the signal propagation in axons

Continuum Mechanics and Thermodynamics ◽

10.1007/s00161-020-00868-2 ◽

2020 ◽

Vol 32 (6) ◽

pp. 1619-1627 ◽

Cited By ~ 1

Author(s):

Jüri Engelbrecht ◽

Kert Tamm ◽

Tanel Peets

Keyword(s):

Signal Propagation ◽

Internal Variables

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A dislocation density-based model for the work hardening and softening behaviors upon stress reversal

Archives of Civil and Mechanical Engineering ◽

10.1007/s43452-021-00239-x ◽

2021 ◽

Vol 21 (2) ◽

Author(s):

Paulina Lisiecka-Graca ◽

Krzysztof Bzowski ◽

Janusz Majta ◽

Krzysztof Muszka

Keyword(s):

Dislocation Density ◽

Electron Backscatter Diffraction ◽

Microstructural Analysis ◽

Back Stress ◽

Carbon Steels ◽

Internal Variables ◽

Low Carbon ◽

Average Dislocation Density ◽

Calculation Results ◽

Mechanical Behaviours

AbstractThe mechanical behaviours of microalloyed and low-carbon steels under strain reversal were modelled based on the average dislocation density taking into account its allocation between the cell walls and cell interiors. The proposed model reflects the effects of the dislocations displacement, generation of new dislocations and their annihilation during the metal-forming processes. The back stress is assumed as one of the internal variables. The value of the initial dislocation density was calculated using two different computational methods, i.e. the first one based on the dislocation density tensor and the second one based on the strain gradient model. The proposed methods of calculating the dislocation density were subjected to a comparative analysis. For the microstructural analysis, the high-resolution electron backscatter diffraction (EBSD) microscopy was utilized. The calculation results were compared with the results of forward/reverse torsion tests. As a result, good effectiveness of the applied computational methodology was demonstrated. Finally, the analysis of dislocation distributions as an effect of the strain path change was performed.

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Generational differences in the placement of clitic se in New York City Spanish

International Journal of Bilingualism ◽

10.1177/13670069211016546 ◽

2021 ◽

pp. 136700692110165

Author(s):

Kevin Martillo Viner

Keyword(s):

New York ◽

New York City ◽

York City ◽

Internal Variables ◽

Chi Square ◽

Ongoing Research ◽

External Variables ◽

Two Generations ◽

Finite Verb ◽

Chi Square Tests

Aims and objectives: This study analyzes the proclitic and enclitic positions of Spanish clitic se (e.g., ella se quería ir / ella quería irse ‘she wanted to go’) across two generations of Spanish speakers in New York City. In an effort to contribute to ongoing research aimed at better understanding Spanish in the US, the following questions are addressed. In syntactic environments that permit variation, does placement of Spanish se differ between the two generations? From the internal variables identified for this study (nonfinite verb type, finite verb, tense of finite verb, grammatical person, use of se, grammatical mood of finite verb, negation), which ones have a statistically significant effect on placement? From the external variables identified for this study (national origin, region, areal origins, sex, age, years in US, socioeconomic class, education, English skill, Spanish skill, general Spanish use), which ones have a statistically significant effect on placement? Design and data: This study is carried out within a variationist-sociolinguistic framework and the sample consists of 50 participants, 25 from the first generation (G1) and 25 from the second (G2). Analysis: Bivariate chi-square tests are performed in order to determine what internal and external variables constrain placement of the dependent variable (clitic se placement). Findings: Generation has a statistically significant effect on placement ( p = .016), wherein proclisis is more frequent amongst the G2 participants. These results corroborate previous research showing an overall preference for proclisis in both monolingual and bilingual/heritage speakers. Further, chi-square tests pinpoint five conditioning effects for G1 (nonfinite verb type, use of se, finite verb, years in US, and English skill), but only two for G2 (use of se and English skill). Originality and implications: The present study is the first to discover strong correlations between the proclitic position and the numerous internal and external variables quantitatively assessed. Future research is thus warranted.

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Viscoelastic phase-field fracture using the framework of representative crack elements

International Journal of Fracture ◽

10.1007/s10704-021-00522-1 ◽

2021 ◽

Author(s):

Bo Yin ◽

Johannes Storm ◽

Michael Kaliske

Keyword(s):

Phase Field ◽

Consistency Condition ◽

Field Method ◽

Anisotropic Elasticity ◽

Phase Field Method ◽

Internal Variables ◽

Crack Model ◽

Material Degradation ◽

Discrete Crack ◽

Deformation State

AbstractThe promising phase-field method has been intensively studied for crack approximation in brittle materials. The realistic representation of material degradation at a fully evolved crack is still one of the main challenges. Several energy split formulations have been postulated to describe the crack evolution physically. A recent approach based on the concept of representative crack elements (RCE) in Storm et al. (The concept of representative crack elements (RCE) for phase-field fracture: anisotropic elasticity and thermo-elasticity. Int J Numer Methods Eng 121:779–805, 2020) introduces a variational framework to derive the kinematically consistent material degradation. The realistic material degradation is further tested using the self-consistency condition, which is particularly compared to a discrete crack model. This work extends the brittle RCE phase-field modeling towards rate-dependent fracture evolution in a viscoelastic continuum. The novelty of this paper is taking internal variables due to viscoelasticity into account to determine the crack deformation state. Meanwhile, a transient extension from Storm et al. (The concept of representative crack elements (RCE) for phase-field fracture: anisotropic elasticity and thermo-elasticity. Int J Numer Methods Eng 121:779–805, 2020) is also considered. The model is derived thermodynamic-consistently and implemented into the FE framework. Several representative numerical examples are investigated, and consequently, the according findings and potential perspectives are discussed to close this paper.

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