scholarly journals Theoretical and Experimental Research on Thermal Field Mathematical Modelling during Welding Load Operations on Active Surfaces of Milling and Cutting Teeth Used for Road Top Stripping

2021 ◽  
Vol 22 (3) ◽  
pp. 104-110
Author(s):  
Daniela Maria Iovănaș ◽  
Author(s):  
S. Kolesnichenko ◽  
A. Popadenko

The paper presents the results of experimental research of the possibility of using thermographic non-destructive testing for the search of cracks in steel structures. The basis of non-destructive thermal control is the registration of changes in the thermal field that occurs in the case of disturbance of the thermodynamic equilibrium of object with an environment that appears on the surface, and parameters of which allows to obtain the necessary information. The thermal control method is based on the interaction of the thermal field of object with thermodynamically sensitive elements (thermocouple, photodetector, liquid crystal element, bolometer) that convert the field parameters (intensity, temperature gradient, contrast, variability) into the electrical signal of the recording device. An experiment is described which proves the possibility of using thermal nondestructive testing for the detection of cracks in steel structures. As measuring instruments for the experiment were used thermal imagers with different resolution of the matrix of the IR image (thermal image), infrared thermohygrometer, luxmeter. The problems encountered during the use of thermal non-destructive testing and possible solutions are indicated. The authors conclude that the thermographic control method can be used in the examination of steel structures for the qualitative assessment of cracks.


2009 ◽  
Vol 40 (2) ◽  
pp. 55-65 ◽  
Author(s):  
Thomas F. Pettigrew

This paper reviews the evidence for a secondary transfer effect of intergroup contact. Following a contact’s typical primary reduction in prejudice toward the outgroup involved in the contact, this effect involves a further, secondary reduction in prejudice toward noninvolved outgroups. Employing longitudinal German probability samples, we found that significant secondary transfer effects of intergroup contact exist, but they were limited to specific outgroups that are similar to the contacted outgroup in perceived stereotypes, status or stigma. Since the contact-prejudice link is bidirectional, the effect is inflated when prior prejudice reducing contact is not controlled. The strongest evidence derives from experimental research. Both cognitive (dissonance) and affective (evaluative conditioning) explanations for the effect are offered.


Sign in / Sign up

Export Citation Format

Share Document