scholarly journals Efficient regular perturbation solutions for beams subjected to thermal imperfections: a case study

2010 ◽  
Author(s):  
B. W. Yeigh ◽  
K.-K. Chan
Keyword(s):  
Regular Perturbation ◽  
Perturbation Solutions

Perturbation Solutions for Spherical Solidification of Saturated Liquids

1973 ◽  
Vol 95 (1) ◽  
pp. 42-46 ◽  
Author(s):  
R. I. Pedroso ◽  
G. A. Domoto
Keyword(s):  
Boundary Condition ◽  
Series Solution ◽  
Freezing Temperature ◽  
Perturbation Solution ◽  
Partial Sums ◽  
Regular Perturbation ◽  
Constant Wall Temperature ◽  
Temperature Boundary ◽  
Temperature Boundary Condition ◽  
Perturbation Solutions

A perturbation solution is obtained for outward and partial inward spherical solidification of a liquid initially at the freezing temperature. The constant-wall-temperature boundary condition is considered with the properties of the solidified material assumed as constants. A nonlinear transformation is applied to the sequence of partial sums in the perturbation solution to increase its range of applicability. For inward solidification it is found that the regular perturbation solution diverges for front positions close to the center. An Euler transformation and an overall energy balance are then used to obtain a modified series solution which is compared with numerical results.

Partial Spectral Expansions for Problems in Thermal Convection

1978 ◽  
Vol 100 (3) ◽  
pp. 435-441 ◽  
Author(s):  
E. J. Shaughnessy ◽  
J. Custer ◽  
R. W. Douglass
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Thermal Convection ◽  
Perturbation Methods ◽  
Nonlinear Partial Differential Equations ◽  
Regular Perturbation ◽  
Spectral Expansions ◽  
Valid Evidence ◽  
Parameter Values ◽  
Perturbation Solutions

The use of spectral expansions for solving nonlinear partial differential equations is explained, and two examples drawn from convective heat transfer are presented. For both problems the results agree well with regular perturbation solutions at parameter values for which the latter remain valid. Evidence is given to indicate that the spectral solutions are valid for considerably larger parameter values than can be reached with the perturbation methods.

Perturbation solutions for highly frictional granular media

2005 ◽  
Vol 461 (2053) ◽  
pp. 21-42 ◽  
Author(s):  
Ngamta Thamwattana ◽  
James M. Hill
Keyword(s):  
Internal Friction ◽  
Granular Media ◽  
Numerical Solutions ◽  
Solution Procedure ◽  
Perturbation Series ◽  
Regular Perturbation ◽  
Approximate Analytical Solutions ◽  
Leading Term ◽  
Flow Through ◽  
Perturbation Solutions

In this paper, we deal with the materials possessing angles of internal friction ϕ for which 1 − sin ϕ is close to zero, and we use the solution for sin ϕ = 1 as the leading term in a regular perturbation series, where the correction terms are of order 1 − sin ϕ . In this way we obtain approximate analytical solutions which can be used to describe the behaviour of real granular materials. The solution procedure is illustrated with reference to quasi–static flow through wedge–shaped and conical hoppers. For these two problems, the obtained perturbation solutions are shown to be graphically indistinguishable from the numerical solutions for high angles of internal friction, and for moderately high angles of internal friction the perturbation solutions still provide excellent approximations.

Parallel Plate Flow of a Third-Grade Fluid and a Newtonian Fluid With Variable Viscosity

2016 ◽  
Vol 71 (7) ◽  
pp. 595-606
Author(s):  
Volkan Yıldız ◽  
Mehmet Pakdemirli ◽  
Yiğit Aksoy
Keyword(s):  
Newtonian Fluid ◽  
Parallel Plate ◽  
Numerical Solutions ◽  
Variable Viscosity ◽  
Third Grade ◽  
Third Grade Fluid ◽  
Regular Perturbation ◽  
Approximate Analytical Solutions ◽  
Grade Fluid ◽  
Perturbation Solutions

AbstractSteady-state parallel plate flow of a third-grade fluid and a Newtonian fluid with temperature-dependent viscosity is considered. Approximate analytical solutions are constructed using the newly developed perturbation-iteration algorithms. Two different perturbation-iteration algorithms are used. The velocity and temperature profiles obtained by the iteration algorithms are contrasted with the numerical solutions as well as with the regular perturbation solutions. It is found that the perturbation-iteration solutions converge better to the numerical solutions than the regular perturbation solutions, in particular when the validity criteria of the regular perturbation solution are not satisfied. The new analytical approach produces promising results in solving complex fluid problems.

The Genesis and Internal Dynamics of El Salvador's People's Revolutionary Army, 1970–1976

2014 ◽  
Vol 38 (01) ◽  
pp. 102-129
Author(s):  
ALBERTO MARTÍN ÁLVAREZ ◽  
EUDALD CORTINA ORERO
Keyword(s):  
Latin America ◽  
El Salvador ◽  
Early Years ◽  
Left Wing ◽  
Internal Dynamics ◽  
Internal Coherence ◽  
The 1960S

AbstractUsing interviews with former militants and previously unpublished documents, this article traces the genesis and internal dynamics of the Ejército Revolucionario del Pueblo (People's Revolutionary Army, ERP) in El Salvador during the early years of its existence (1970–6). This period was marked by the inability of the ERP to maintain internal coherence or any consensus on revolutionary strategy, which led to a series of splits and internal fights over control of the organisation. The evidence marshalled in this case study sheds new light on the origins of the armed Salvadorean Left and thus contributes to a wider understanding of the processes of formation and internal dynamics of armed left-wing groups that emerged from the 1960s onwards in Latin America.

Culture and the plasticity of perception

2020 ◽  
Vol 43 ◽  
Author(s):  
Michael Lifshitz ◽  
T. M. Luhrmann
Keyword(s):  
Cultural Context ◽  
Sensory Experience ◽  
Cultural Learning ◽  
The World

Abstract Culture shapes our basic sensory experience of the world. This is particularly striking in the study of religion and psychosis, where we and others have shown that cultural context determines both the structure and content of hallucination-like events. The cultural shaping of hallucinations may provide a rich case-study for linking cultural learning with emerging prediction-based models of perception.

Dual systems for all: Higher-order, role-based relational reasoning as a uniquely derived feature of human cognition

2019 ◽  
Vol 42 ◽  
Author(s):  
Daniel J. Povinelli ◽  
Gabrielle C. Glorioso ◽  
Shannon L. Kuznar ◽  
Mateja Pavlic
Keyword(s):  
Temporal Reasoning ◽  
Higher Order ◽  
Important Case ◽  
Human Cognition ◽  
Relational Reasoning ◽  
Dual Systems ◽  
First Order ◽  
Reasoning System ◽  
Role Based

Abstract Hoerl and McCormack demonstrate that although animals possess a sophisticated temporal updating system, there is no evidence that they also possess a temporal reasoning system. This important case study is directly related to the broader claim that although animals are manifestly capable of first-order (perceptually-based) relational reasoning, they lack the capacity for higher-order, role-based relational reasoning. We argue this distinction applies to all domains of cognition.

Sociocultural memory development research drives new directions in gadgetry science

2019 ◽  
Vol 42 ◽  
Author(s):  
Penny Van Bergen ◽  
John Sutton
Keyword(s):  
Episodic Memory ◽  
Autobiographical Memory ◽  
Developmental Psychology ◽  
Cross Cultural ◽  
Memory Development ◽  
Development Research ◽  
Cultural Research ◽  
New Directions ◽  
Cross Cultural Research

Abstract Sociocultural developmental psychology can drive new directions in gadgetry science. We use autobiographical memory, a compound capacity incorporating episodic memory, as a case study. Autobiographical memory emerges late in development, supported by interactions with parents. Intervention research highlights the causal influence of these interactions, whereas cross-cultural research demonstrates culturally determined diversity. Different patterns of inheritance are discussed.

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