Structural formation during bread baking in a combined microwave-convective oven determined by sub-second in-situ synchrotron X-ray microtomography.

A new concept has been developed for characterizing the real-time evolution of the three-dimensional pore and lamella microstructure of bread during baking using synchrotron X-ray microtomography (SRµCT). A commercial, combined microwave-convective oven was modified and installed at the TOMCAT synchrotron tomography beamline at the Swiss Light Source (SLS), to capture the 3D dough-to-bread structural development in-situ at the micrometer scale with an acquisition time of 400 ms. This allowed characterization and quantitative comparison of three baking technologies: (1) convective heating, (2) microwave heating, and (3) a combination of convective and microwave heating. A workflow for automatic batchwise image processing and analysis of 3D bread structures (1530 analyzed volumes in total) was established for porosity, individual pore volume, elongation, coordination number and local wall thickness, which allowed for evaluation of the impact of baking technology on the bread structure evolution. The results showed that the porosity, mean pore volume and mean coordination number increase with time and that the mean local cell wall thickness decreases with time. Small and more isolated pores are connecting with larger and already more connected pores as function of time. Clear dependencies are established during the whole baking process between the mean pore volume and porosity, and between the mean local wall thickness and the mean coordination number. This technique opens new opportunities for understanding the mechanisms governing the structural changes during baking and discern the parameters controlling the final bread quality.

Three-dimensional liquid foam flow through a hopper resolved by fast X-ray microtomography.

We probe the complex rheological behaviour of liquid foams flowing through a conical constriction. With fast X-ray tomographic microscopy we measure in situ the displacement and deformation of up to fifty thousand bubbles at any single time instance while varying systematically the foam liquid fraction, the bubble size and the flow direction - convergent vs. divergent. The large statistics and high spatio-temporal resolution allows to observe and quantify the deviations from a purely viscous flow. We indeed reveal an asymmetry between the convergent and divergent flows associated to the emergence of elastic stresses in the latter case, and enhanced as the liquid fraction is reduced. Such effect is related to the reorientation of the deformed bubbles flowing out of the constriction, from a prolate to an oblate shape in average, while they pass through the hopper waist.

Symptomatic Distal Ureteral Stone in an Ileal Ureter: Treatment by Combined Supine Ureteroscopy and Mini Percutaneous Nephrolithotomy.

Urolithiasis is a well-known and common late complication in patients with urinary diversion. Patients without urinary diversion lead to symptoms such as hematuria and ureteral colic, whereas stones in patients with urinary diversion tend to be asymptomatic and are often diagnosed incidentally during staging examinations of oncologic diseases. We report the case of a 64-year-old male patient with a lower pole kidney stone and a stone in the ileal ureter substitution. He presented with diffuse abdominal and left-sided flank pain. CT revealed the diagnosis of urolithiasis in the ileal ureter substitution and the lower pole of the left kidney. We performed a combined retrograde, flexible ureteroscopy and a mini percutaneous nephrolithotomy (combined intrarenal surgery) without any complications and no residual stone fragments postoperatively. This case presentation demonstrates that in patients with urinary tract diversion, urolithiasis can still cause problems.