Papers by Keyword: Confocal Microscopy

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Authors: M. Ahmadian, M. Reid, Rian Dippenaar, Tara Chandra, David Wexler, Andrzej Calka
Abstract: The densification behavior of WC composites based on iron aluminide binder was investigated using laser scanning confocal mi¬croscopy (LSCM). Doped Fe60Al40 alloys with boron levels ranging from 0 to 0.1 wt% were used as the aluminide binders. The aluminide binders were prepared using controlled atmosphere ring grinding and then blended with WC powder. The composite powder compacted in an alumina crucible and held in a platinum holder in the confocal microscope. The temperature increased from ambient temperature up to 1500 °C under high purity argon. The presence of boron was found to facilitate compaction of the composites and improve the wetting between WC and FeAl binder during liquid phase sintering. Increasing the amount of boron in the binder resulted in the melting of binder at lower temperature and increasing of the compacting of the intermetallic tungsten carbide composites.
Authors: Y.H. Wang, X.F. Yu, Ye Tai Fei
Abstract: Based on the differential confocal microscopy principle, a non-scanning 3D profile detecting system is proposed. A 2D light source array produced by micro-optic components is used to form a parallel micro-confocal system. The whole field detecting of the measuring plane is realized. The reflected light beam is divided into two paths. Two CCD cameras work together to detect the facula array in a differential arrangement. A differential algorithm of facula intensity is used. The noise and the shift of light source can be avoided effectively. Using the linearity characteristic of the differential confocal system, the high axial resolution is achieved at a larger sampling interval. The measuring efficiency and accuracy can be increased. The construction and working principle of the 3D parallel detecting system and the 3D profile reconstruction method are investigated. Experiment results agree with the ones of theory analysis. It indicates that the differential method is applicable for non-scanning 3D profile detection.
Authors: Liang Chia Chen, Wei Chieh Kao, Yao Ting Huang
Abstract: A new full-field 3-D micro surface profilometer using digital micromirror device (DMD)-based fringe projection strategy and confocal principle is presented in the article. In viewing the fact that conventional laser confocal measurement method not only easily encounters undesired irregular scattering problems, but also lack scanning efficiency due to its single-point type measurement, the newly developed automatic surface profilometer deploys a DMD chip to project spatially encoded digital fringe patterns with dynamic light intensity, onto the object to obtain excellent measurement performance. A novel digital fringe pattern design with adaptive sinusoidal intensity modulation was developed for active fringe projection, to obtain optimized depth resolution with a micrometer lateral resolution in confocal measurement. Some of semiconductor components have been measured to attest the feasibility of the developed approach. The depth measurement resolution can reach better than 0.1μm and the maximal measured error was verified to be less than less than 0.5 % of the measured step size.
Authors: Artem Minin, Ilya Byzov, Mikhail Uimin, Anatoly Ye. Ermakov, Nina Shchegoleva, Sergey Zhakov, Leonid Smoluk, Maria Ulitko, Artem Minin
Abstract: The simultaneous combination of optical and magnetic properties of nanoparticles would greatly benefit in vivo disease diagnosis as well as in situ monitoring of cell in cell culture. The most promising application of magnetic particles in biomedicine is MRI contrast enhancement and magnetic hyperthermia. Another important thing is the determination of exact localization of nanoparticles in the cell culture that can be defined by e.g. optical way. In our investigation we used the iron nanoparticles encapsulated in carbon as a magnetic component and carbon quantum dots as an optical labels to provide the photostability and fluorescence in a wide range of wavelengths. In order to avoid the fluorescence quenching in bimodal particles the optical and magnetic components should be separated by insulator layer. To create the optimal bimodal nanoparticles for this purpose the non-typical configuration of nanocomposites was realized, namely, a fluorescent core was separated from the coated magnetic particles by silicon dioxide matrix. Finally, it was shown that these bimodal nanocomposites demonstrate the high magnetic properties, good visualized ability and low toxicity for living cells as well.
Authors: C.M. Botelho, Roger A. Brooks, Serena Best, M.A. Lopes, José D. Santos, Neil Rushton, William Bonfield
Authors: Núria Llorca-Isern, Gemma Bertran-Vidal
Abstract: Free-standing samples of plasma sprayed cordierite with a high level of porosity were heat treated at different temperatures and for different holding times in order to study the densification process. Optimisation of a new characterisation methodology for the interconnected defects network in the specimens of plasma sprayed cordierite based on fluorescence confocal scanning laser microscopy (CSLM) information was the main objective of the present work. Optical, electron and confocal microscopes were use to determine percentage, distribution and morphology of the defects in the specimens. Fractal geometry combined to the CSLM images was useful for evaluating structural characteristics, complexity and level of connectivity of the defects network of these samples. All this information allowed studying the level of densification accomplished by the samples under the different thermal treatments conditions. After the evaluation of the results produced, this methodology can be validated for other applications or processes such as conventional sintering, etc. Results showed low percentage of porosity with dispersion the latter related to the degree of anisotropy of the samples. However an increase of porosity with the crystallisation was also observed.
Authors: Sebastian Stach
Abstract: The aim of the paper is to present comparative studies of the parameters of the fracture surface topography of titanium alloy, obtained by means of two techniques. The research equipment consisted of a Taylor Hobson profilographometer, Talysurf, and a confocal microscope, LEXT OLS 3000 by Olympus. By means of a contact and non-contact method, files of coordinates of the investigated surfaces were obtained, based on which some chosen stereometric parameters were calculated. The tests carried out as part of the study confirmed the usefulness and the possibility of using a confocal microscope as a modern instrument for evaluating the topography of non-planar surfaces. In the case of statistical parameters representing the whole surface under examination, very high convergence of the stereometric structure parameters was obtained, described by means of profilographometry and confocal microscopy methods.
Authors: Daniel R. East, Mark H. Reid, Mark A. Gibson, Rian J. Dippenaar, Robert G. O'Donnell
Abstract: The application of moderate cooling rates to metal alloys of certain composition can generate metals that exhibit an amorphous microstructure on a bulk scale. This phenomenon is related to the avoidance of the nucleation of the competing crystalline phases associated with the alloy during solidification. This work describes the devitrification behaviour of the bulk glass forming Mg60Cu29Gd11 system through the use of a number of analytical techniques including DSC, laser confocal microscopy, SEM and XRD. Attention is drawn to the correlation between the more common analytical techniques and the observation of phase transformations on the surface of the metal, evident using a laser scanning confocal microscope fitted with a heating stage.
Authors: Michal Matysík, Iveta Plšková, Zdeněk Chobola
Abstract: The aim of this paper is to evaluate the possibility of using the Impact-echo method for assessment of extremely long period of frost resistance of ceramic tiles. Sets of ceramic tiles of the Ia class to EN 14 411 B standard made by manufacture RACOs have been analyzed. The ceramic tiles under investigation have been subjected to 500 freeze-thaw-cycle based degradation in compliance with the relevant EN ISO 10545-12 standard. To verify the correctness of the Impact-echo method results, additional physical properties of the ceramic tiles under test have been measured. To analyze the specimen surface condition, we also used Olympus LEXT 3100 confocal scanning microscope. It has been proved that the acoustic method Impact-echo is a sensitive indicator of the structure condition and can be applied to the ceramic cladding element frost resistance and service life prediction assessment.
Authors: Jitka Krejsová, Magdaléna Doleželová, Alena Vimmrová
Abstract: The gypsum mortars with different types of aggregate were studied. The surface roughness of fine aggregates and the fracture surface roughness were evaluated by a confocal laser scanning microscopy. Four gypsum mortars and one gypsum paste were tested. The results from the confocal laser scanning microscopy (CLSM) are compared with the pictures of grain surface taken by a scanning electron microscopy (SEM) and both methods seem to be appropriate for surface evaluation. The influence of the surface aggregate roughness on some gypsum mortar properties is demonstrated.
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