Laser-Speckle-Photometry – A Method for Non-Contact Evaluation of Material Damage, Hardness and Porosity

Cikalova, Ulana; Bendjus, Beatrice; Schreiber, J.

doi:10.3139/120.110299

Cited by 10 publications

(4 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Detailed investigations to determine subsurface fatigue processes by the use of the non-destructive Barkhausen method involving RCF have been published. 33,[36][37][38][39][40][41] The authors used the results for the differentiation between magnetisation changes due to surface deformation induced by rolling contact and subsurface material.…”

Section: Experimental Methodsmentioning

confidence: 99%

Study of subsurface initiation mechanism for white etching crack formation

Diederichs

Barteldes²,

Schwedt

et al. 2016

Materials Science and Technology

View full text Add to dashboard Cite

The present paper describes a novel way to detect early stages in the gradual transformation of SAE 52100 bearing steel material to white etching cracks (WEC). The underlying transformation is recorded and investigated by a complementary use of Barkhausen noise measurements, ultrasonic measurements and scanning electron microscopy. While ultrasonic measurements can only be used to detect cracks in a failed component, the recently improved Barkhausen noise measurement technique can be used to detect possible early stages of microstructural transformation. A cross section from a region without ultrasonic signal but with a Barkhausen signal has been investigated by the use of scanning electron microscopes in order to reveal possible pre-stages of WEC formation. These findings support that WEC are locally initiated in subsurface regions. Within those modified regions, carbides start to dissolve in consequence of deformation accumulation, which has been identified as an early state of WEA microstructure formation. This paper is part of a Themed Issue on Recent developments in bearing steels.

show abstract

Section: Experimental Methodsmentioning

confidence: 99%

Study of subsurface initiation mechanism for white etching crack formation

Diederichs

Barteldes²,

Schwedt

et al. 2016

Materials Science and Technology

View full text Add to dashboard Cite

show abstract

“…detector. Among other things, laser speckle imaging can be used to determine material properties such as hardness and porosity [30,[32][33][34][35].…”

Section: Practical Applicationmentioning

confidence: 99%

“…When biological objects are irradiated with coherent light, backscattered fluctuating interference patterns called dynamic speckles or biospeckles are formed. The temporally or spatially resolved fluctuation of the dynamic speckle pattern -biospeckle activity -is caused by physical or biological processes affecting the illuminated object [33,36,[39][40][41][42][43][44].…”

Section: Practical Applicationmentioning

confidence: 99%

See 1 more Smart Citation

Monitoring the apical growth characteristics of hairy roots using non‐invasive laser speckle contrast imaging

Schott

Bley

Walter

et al. 2021

Engineering in Life Sciences

View full text Add to dashboard Cite

Hairy roots are used to produce plant agents and additives. Due to their heterogeneous structure and growth characteristics, it is difficult to determine growthrelated parameters continuously and in real time. Laser speckle contrast analysis is widely used as a non-destructive measurement technique in material testing or in medical technology. This type of analysis is based on the principle that moving objects or particles cause fluctuations in stochastic interference patterns known as speckle patterns. They are formed by the random backscattering of coherent laser light on an optically rough surface. A Laser Speckle Imager, which is well established for speckle studies of hemodynamics, was used for the first time for non-invasive speckle measurements on hairy roots to study dynamic behavior in plant tissue. Based on speckle contrast, a specific flux value was defined to map the dynamic changes in the investigated tissue. Using this method, we were able to predict the formation of lateral strands and to identify the growth zone in the apical root region, as well as dividing it into functional regions. This makes it possible to monitor physiological processes in the apical growth zone in vivo and in real time without labeling the target structures.

show abstract

Biospeckle‐characterization of hairy root cultures using laser speckle photometry

Schott

Steingroewer

Bley

et al. 2020

Engineering in Life Sciences

View full text Add to dashboard Cite

Monitoring is indispensable for the optimization and simulation of biotechnological processes. Hairy roots (hr, plant tissue cultures) are producers of valuable relevant secondary metabolites. The genetically stable cultures are characterized by a rapid filamentous growth, making monitoring difficult with standard methods. This article focuses on the application of laser speckle photometry (LSP) as an innovative, non‐invasive method to characterize Beta vulgaris (hr). LSP is based on the analysis of time‐resolved interference patterns. Speckle interference patterns of a biological object, known as biospeckles, are characterized by a dynamic behavior that is induced by physical and biological phenomena related to the object. Speckle contrast, a means of measuring the dynamic behavior of biospeckles, was used to assess the biospeckle activity. The biospeckle activity corresponds to processes modifying the object and correlates with the biomass growth. Furthermore, the stage of the cultures’ physiological development was assessed by speckle contrast due to the differentiation between active and low active behavior. This method is a new means of monitoring and evaluating the biomass growth of filamentous cultures in real time. As a potential tool to characterize hairy roots, LSP is non‐invasive, time‐saving, can be used online and stands out for its simple, low‐cost setup.

show abstract

Laser-Speckle-Photometry – A Method for Non-Contact Evaluation of Material Damage, Hardness and Porosity

Cited by 10 publications

References 2 publications

Study of subsurface initiation mechanism for white etching crack formation

Study of subsurface initiation mechanism for white etching crack formation

Monitoring the apical growth characteristics of hairy roots using non‐invasive laser speckle contrast imaging

Biospeckle‐characterization of hairy root cultures using laser speckle photometry

Contact Info

Product

Resources

About