• Surrounded by silo container, yet don't master the design w.r.t. type of granular material to handle
• difficult to predict precisely flow pattern, local movement of grains

• granular materials are very good candidates for X-ray tomography investigation
• Mechanical properties, cohesiveness of particles and silo structure (hopper angle, wall roughness) play important roles in flow pattern and discharge velocity
• Discrete Element Method (DEM) is often used to predict granular flow

• Design versatile silo that can generate wide variety of flow conditions
• Investigate various materials and carry out mechanical propoerty measurements
• Carry out time-lapse X-ray tomography study of silo discharge for different materials
• Comparison between X-ray tomography data and structural-faithful DEM simulation

• Funds: Polish National Science Centre (NCN) - OPUS10 - 320 000 PLN (July 2016- Decembre 2018)
• Team: L. Babout (coordinator), K. Grudzień, S. Waktola (PhD), K. Miśkiewicz (PhD)
• Collaboration: Gdansk Univ. Technolog. (M. Szkodo, M. Niedostatkiewicz) / PAN Lublin (J. Wiącek) / INSA-Lyon (E. Maire, J. Adrien)
• Open data: different studied granular packing can be found here and free of use under ODC licence.

versatile silo

Movie: a glimpse into X-ray CT experiment

reconstructed coronal views of silo discharge (sorghum, eccentric mass flow)

comparison between 3D tomography and DEM

• cracking has non-negligible social and economical impact on our lives
• difficult to predict, even understand

• strong interaction between crack and material microstructure
• in each case of damage accumulation the crack path is interrupted, deflected and bridged (see fig. top)
• bridging ligaments can slow down crack propagation and increase lifetime

• case of intergranular stress corrosion cracking (IGSCC)
• extract bridges for geometrical characterisation
• localise bridges wrt. crack front
• comparison with results from Diffraction Contrast Tomography

• development of hole filling algorithm (HFA) to localise and extract bridges (see fig. middle)
• image registration approach to follow full process of bridging creation and failure towards sample fracture (bottom animation)

2D reconstructed image: bridges (marked in red) along crack (black) in material (grey)

3D image: bridges (red) along 3D crack (yellow) after HFA

animation showing crack history up to fracture of specimen (grey)

• titanium alloy: a myriad of applications (e.g. biomedical, areonautics)
• very good performance at high temperature
• strong dependance on microstructure

• strong interaction between crack and material microstructure
• in the case of lamellar microstructure (see fig. top), strong influence of α-colony and β grain boundaries on crack path
• revealed by X-ray microtomography and EBSD

• segment α-colony in 3D
• segment β grain boundaries in 3D
• segment crack
• correlate crack with the other features

• Creation of CHG directional filter bank to classify α-colonies of different directionality (13 different directions). (see fig. middle)
• Segmentation of β-gb and crack also based on CHG filtering. Here mainy used to remove defects from the surface (directional filtering)
• Quantitative characterization of the type of cracking (trans-/inter-lamellar) made possible (see fig. down)

segmentation of α-lamellae using CHG-based method in the case of Ti alloy. Red boundaries correspond to β-gb and balck to some α-colony boundaries

3D view showing how superpostion of crack (grey) with α-lamellae and β-gb (yellow) can help understanding cracking phenomenon

• increased number of patients suffering from asthma problems
• CT scans helps in the diagnosis
• difficulty in follow-up procedure, due to lack of quantitative method

• software to quantify airway tree
• localise tree cross-sections with potential closure problems
• facilitate follow-up procedure for the doctor with pseudo-automatic diagnostic

• defect correction for wall segmentation using HFA-based method
• tree partitioning after skeletonization (see fig. top)
• robust tangent estimator to reconstruct local cross-sections
• quantitative analysis of local bronchi size and wall thickness (see fig. bottom)

partitioning of the bronchi after skeletonization and graph representation

view and analysis of a reconstructed bronchi section

• ECT: fast and cheap tomography method
• main problem: reliability in data due to limited amount of measurements(image)
• increasing the number of electrodes is not an issue

• design rotatable sensor to increase no. of measurement
• study sensor response in static and dynamic modes

• sensors with 16 elecrodes wich fits to flow installation (see fig. top)
• evident image accuracy improvement on static phantom as no. of rotation steps increases (see fig. bottom)

• improve image acquistion and reconstruction
• feasibility study during dynamic measurements of pneumatic conveying

sensor mounted on flow installation

comparision with 32-electrodes sensor. RS - rotation step