Opportunities for students

Here we suggest several topics for pursuing Ph.D. studies in our laboratory. However, it is possible to work on Bachelor's and Master's theses as well! The list of topics is not limited, so in case of interest, please contact tomas.zikmund@ceitec.vutbr.cz.


Reduction of limitations of the tomographic reconstruction 

Supervisor: prof. Ing. Jozef Kaiser, Ph.D.

Supervisor-specialist: Ing. Tomáš Zikmund, Ph.D.

Tomographic reconstruction is the key part of the Computed Tomography (CT) data acquisition procedure. It is a type of multidimensional inverse problem where the aim is to acquire an estimate of a specific system from a finite number of projection images acquired during CT measurement. Various methods have been developed to solve this problem, most of them based on inverse solution of the Radon transform.  However, using such approach several conditions must be fulfilled to acquire correct reconstructed information. These are mainly related to CT measurement scenario in terms of acquired number of projection images, used measurement geometry or the dimensions of the sample. Aim of this thesis is to study limitations of the tomographic reconstruction and to develop practical solution for their reduction. 


Correlation of X-ray computed tomography with microscopic techniques for material characterisation

Supervisor: prof. Ing. Jozef Kaiser, Ph.D.

Supervisor-specialist: Ing. Tomáš Zikmund, Ph.D.

X-ray computed tomography (CT) is an important method for 3D non-destructive imaging of samples in many fields. It is commonly used in industry for defect detection and quality control, scientific projects utilise imaging and quantification of data and apply a number of analyses to determine morphological and physical parameters. To put CT data in context with other methods, they often have to be supplemented with established imaging methods such as electron and light microscopy and qualitative techniques such as X-ray spectroscopy.

The data from each technique typically have a different format, size, resolution, etc. Combining such different information about samples is a challenge. When correlating two different 3D datasets, it is necessary to ensure that the sample structures correspond to each other. For a combination of 2D and 3D techniques, a corresponding 2D section has to be found in the 3D dataset. This requires a programming approach or a use of special software. The work will deal with techniques of correlation of information from various imaging methods. Such a multidisciplinary approach is in high demand today and has a big potential.


X-ray computed tomography in dimensional metrology

Supervisor: prof. Ing. Jozef Kaiser, Ph.D.

Supervisor-specialist: Ing. Tomáš Zikmund, Ph.D.

Non-destructive imaging method of X-ray computed tomography (CT) is very suitable for dimensional metrology. Through the development of standards it is also becoming accepted as a metrology tool. In comparison with conventional tactile and/or optical coordinate measuring machines (CMM), the CT advantage is analysis of outer and inner features of the sample. CT provides high information density and samples of any surface, shape or material can be measured (up to limit of density and thickness penetrable by X-rays). However CT measurement uncertainties caused by tomography artifacts or multimaterial samples still occur and reduce the measurement accuracy. The aim of this work is to develop practical solutions for CT measurement and the subsequent comparison of the proposed measument procedures with conventional methods of dimensinal metrology.


Material evaluation and characterisation by X-ray computed tomography

Supervisor: prof. Ing. Jozef Kaiser, Ph.D.

Supervisor-specialist: Ing. Tomáš Zikmund, Ph.D.

Image processing and computer vision are of fundamental importance to any field in which images must be enhanced, manipulated, and analysed. The image processing has a crucial role in remote sensing, medical imaging, industrial inspection, material science, and more. Topic includes image formation, image filtering theory, image enhancement, image reconstruction, image registration, and 3D visualisation. It is emphasised at computational techniques for implementing useful image processing and computer vision functions. The performed workflows will be adapted to the specific needs of material analysis using the newest techniques related to the X-ray computed tomography (such as phase retrieval, 3D reconstruction, integration of complementary information).


X-ray computed tomography of mineralised and soft tissues of biological samples

Supervisor: prof. Ing. Jozef Kaiser, Ph.D.

Supervisor-specialist: Ing. Tomáš Zikmund, Ph.D.

X-ray micro computed tomography is becoming one of the commonly used imaging methods in the fields of developmental biology and other biological disciplines. In the native sample only the mineralised bones are visible in the microCT scan, the visualization of the soft tissues requires the staining of the sample in the solutions of elements with high proton number. When the scans of the same sample in native and stained condition is combined the time-consuming process of segmenting the mineralised bones from the stained dataset can be skipped, this new approach enables much faster method of analysing the complex biological samples. In the scope of this work the optimising of the staining method of soft tissues and co-registration of both stained and native scans of same sample will be performed.  


Depth profiling of layered materials using laser spectroscopy

Supervisor: prof. Ing. Jozef Kaiser, Ph.D.

Supervisor-specialist: Ing. Pavel Pořízka, Ph.D./ Ing. Tomáš Zikmund, Ph.D.

Engineering and production of novel materials, including coatings and layers, is demanding new analytical solutions. Compared to other analytical techniques, Laser-Induced Breakdown Spectroscopy (LIBS) enables selective ablation of layers with variable depth resolution. However, the depth of the analysis with certain number of laser pulses differs for individual materials. The calibration of depth to laser pulse number is also of an issue, while there is no solid evidence for this phenomenon in classical LIBS literature. The goal of this thesis is to find complementary approaches, for instance using Computed Tomography and standard approaches of metallography, in depth profiling in order to fully calibrate LIBS technique to depth profile analysis. As an output, methodological protocol applicable across broad range of materials is demanded.