Analytical Solution of a Generalized Two-Dimensional Model for Laser-Flash Thermal Diffusivity Measurements

2019 ◽  
Vol 33 (2) ◽  
pp. 300-308
Author(s):  
Nenad D. Milošević
Keyword(s):  
Thermal Diffusivity ◽  
Analytical Solution ◽  
Laser Flash ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Diffusivity Measurements ◽  
Two Dimensional Model

scholarly journals Analytical solution of a two-dimensional model of liquid chromatography including moment analysis

2014 ◽  
Vol 116 ◽  
pp. 576-589 ◽  
Author(s):  
Shamsul Qamar ◽  
Farman U. Khan ◽  
Yasir Mehmood ◽  
Andreas Seidel-Morgenstern
Keyword(s):  
Liquid Chromatography ◽  
Analytical Solution ◽  
Moment Analysis ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Two Dimensional Model

Modeling Flash Diffusivity Experiments in Two Dimensions for Thick Samples

2008 ◽  
Author(s):  
Robert L. McMasters
Keyword(s):  
Experimental Data ◽  
Laser Flash ◽  
Two Dimensions ◽  
Flash Method ◽  
Two Dimensional ◽  
Dimensional Model ◽  
One Dimensional ◽  
Two Dimensional Model ◽  
Dimensional Analysis Method ◽  
Flash Diffusivity

The laser flash method for measuring thermal diffusivity is well established and has been in use for many years. Early analysis methods employed a simple model, in which one dimensional transient conduction was assumed, with insulated surfaces during the time subsequent to the flash. More recently, models of grater sophistication have been applied to flash diffusivity experiments. These models have been matched to experimental data using nonlinear regression and assume one-dimensional conduction. The advanced models have achieved highly accurate agreement with experimental data taken from thin samples, on the order of one millimeter in thickness. As samples become thicker, models which neglect edge losses can lose some conformity to the experimental data. The present research involves the application of a two dimensional model which allows for penetration of the laser flash into the sample. The accommodation of the flash penetration is important for porous materials, where the coarseness of the porosity is more than one percent of the sample thickness. Variability of the area of incidence of the flash is also investigated to determine the effect on the model and the results. Statistical methods are used in order to make a determination as to the validity of the two dimensional model, as compared with the one dimensional analysis method.

Commitment to pro- versus counter-attitudinal behavior and the dynamics of social representations

2002 ◽  
Vol 61 (1) ◽  
pp. 34-44 ◽  
Author(s):  
Eric Tafani ◽  
Lionel Souchet
Keyword(s):  
Higher Education ◽  
Social Representations ◽  
Cognitive Restructuring ◽  
Social Representation ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Social Actions ◽  
The Social ◽  
Two Dimensional Model ◽  
Students Attitudes

This research uses the counter-attitudinal essay paradigm ( Janis & King, 1954 ) to test the effects of social actions on social representations. Thus, students wrote either a pro- or a counter-attitudinal essay on Higher Education. Three forms of counter-attitudinal essays were manipulated countering respectively a) students’ attitudes towards higher education; b) peripheral beliefs or c) central beliefs associated with this representation object. After writing the essay, students expressed their attitudes towards higher education and evaluated different beliefs associated with it. The structural status of these beliefs was also assessed by a “calling into question” test ( Flament, 1994a ). Results show that behavior challenging either an attitude or peripheral beliefs induces a rationalization process, giving rise to minor modifications of the representational field. These modifications are only on the social evaluative dimension of the social representation. On the other hand, when the behavior challenges central beliefs, the same rationalization process induces a cognitive restructuring of the representational field, i.e., a structural change in the representation. These results and their implications for the experimental study of representational dynamics are discussed with regard to the two-dimensional model of social representations ( Moliner, 1994 ) and rationalization theory ( Beauvois & Joule, 1996 ).

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