Development of the Focused Malley Probe as a Local Aero-Optical Measurement Technique

2022 ◽  
Author(s):  
Luke N. Butler ◽  
Stanislav Gordeyev
Keyword(s):  
Measurement Technique ◽  
Optical Measurement

Timber screw connection: Study of the strain along the interface using optical measurement techniques and simulations

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 3859-3873
Author(s):  
Cedou Kumpenza ◽  
Andreas Ringhofer ◽  
Thomas Krenke ◽  
Adeayo Sotayo ◽  
Maximilian Pramreiter ◽  
...  
Keyword(s):  
Measurement Technique ◽  
Optical Measurement ◽  
Speckle Pattern ◽  
Measurement Techniques ◽  
Axial Loading ◽  
Electronic Speckle Pattern Interferometry ◽  
Pull Out ◽  
Grain Orientations ◽  
Thread Length ◽  
D 12

In various engineering applications, self-tapping screws are used to connect timber members. To describe their load-deformation relationship, a better understanding of the strain along the mechanical interface (i.e., timber-screw interface) is required. With a focus on the axial loading of self-tapping screws, only a few studies have dealt with the determination of the strain based on optical measurement techniques. Therefore, in the present study, the strain distribution at the timber-screw interface was monitored during pull-out tests using an optical measurement technique, called electronic speckle pattern interferometry (ESPI). Strains obtained from the ESPI measurements were compared with the results obtained from structural simulations conducted with finite element modelling (FEM). Three different types of solid spruce wood (Picea abies (L.) Karst.) specimens with different grain orientations connected with self-tapping screws (thread length lg = 130 mm, outer thread diameter d = 12 mm) were tested in withdrawal. There was a good agreement between the ESPI and FEM results, confirming that ESPI was a suitable measurement technique. The study also provided insights and results regarding the region of strain concentrations across the length of self-tapping screws.

Variations in the Measured Carrier Lifetimes of n- 4H-SiC Epilayers

2008 ◽  
Vol 600-603 ◽  
pp. 489-492
Author(s):  
Paul B. Klein ◽  
Joshua D. Caldwell ◽  
Amitesh Shrivastava ◽  
Tangali S. Sudarshan
Keyword(s):  
Measurement Technique ◽  
Reasonable Agreement ◽  
Optical Measurement ◽  
Measurement Techniques ◽  
Carrier Dynamics ◽  
Injection Level ◽  
Carrier Lifetimes ◽  
Dynamics Simulations ◽  
Recombination Kinetics ◽  
Insight Into

The effects of measurement technique and measurement conditions (injection level, temperature) on the measured carrier lifetimes in n- 4H-SiC epilayers are investigated. For three optical measurement techniques, it is shown that the high and low injection lifetimes can vary dramatically. Differences in the lifetime for varying injection level and temperature are approached both experimentally and via carrier dynamics simulations, assuming Z1/Z2 as the dominant defect. Reasonable agreement between measured and calculated behavior is obtained, as is insight into the recombination kinetics associated with the lifetime limiting defect.

Raman microspectroscopy and multivariate data analysis: optical differentiation of aqueous d- and l-tryptophan solutions

2017 ◽  
Vol 19 (45) ◽  
pp. 30533-30539 ◽  
Author(s):  
H. Koch ◽  
S. Polepil ◽  
K. Eisen ◽  
S. Will
Keyword(s):  
Raman Spectroscopy ◽  
Data Analysis ◽  
Intermolecular Interactions ◽  
Measurement Technique ◽  
Multivariate Data Analysis ◽  
Optical Measurement ◽  
Multivariate Data ◽  
Raman Microspectroscopy

The combination of Raman spectroscopy as a sensitive and selective optical measurement technique and multivariate data analysis forms a powerful tool for probing intermolecular interactions between enantiomers.

Development of a novel optical measurement technique to investigate the hot cracking susceptibility during laser beam welding

2018 ◽  
Vol 63 (2) ◽  
pp. 435-441 ◽  
Author(s):  
N. Bakir ◽  
V. Pavlov ◽  
S. Zavjalov ◽  
S. Volvenko ◽  
A. Gumenyuk ◽  
...  
Keyword(s):  
Laser Beam ◽  
Measurement Technique ◽  
Optical Measurement ◽  
Laser Beam Welding ◽  
Hot Cracking

New Measurement Method of Concrete Pavement Surface Macro-Texture

2011 ◽  
Vol 382 ◽  
pp. 293-299
Author(s):  
Meng Cui ◽  
Hong Wei Kang ◽  
Zheng Wei Zhang
Keyword(s):  
Measurement Technique ◽  
Optical Measurement ◽  
Point Clouds ◽  
Concrete Pavement ◽  
Concrete Pavements ◽  
Cement Concrete ◽  
Pavement Surface ◽  
Texture Model ◽  
Dense Point ◽  
Sand Patch

Surface macro-texture in rigid pavements plays an important role in providing safety (providing skid reswastant surfaces) for the traveling public. In general, macro-texture of cement concrete pavements had been measured through sand patch method in China. With the development of measurement technique, some quick methods were applied, such as laser cross-section instrument. But it was unsuitable for the grooving concrete pavement because of its restrictions on measurement principle. So measurement of concrete pavement surface macro-texture based on 3-D optical dense point clouds was introduced in this paper. First, 3-D coordinates of the pavement surface were obtained by the 3-D optical measurement system, then 3-D texture model would be rebuilt with self-programming softwwere, at last the Mean Texture Depth (MTD) of surface could be calculated and compwered with sand patch method. The article studies brooming, grooving and exposed-aggregate cement concrete pavements, and make a correlation analyswas between MTD values of these two methods. The results indicated that they had good correlation, and the measurement technique based on 3-D optical dense point clouds could be used to evaluate cement concrete pavement surface macro-texture quickly

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