Voxel-Scale Digital Volume Correlation

Among various correlation techniques to find the displacement field of a volume imaged by X-ray tomography at several deformation states, a new approach is proposed where the displacement is measured down to the voxel scale and determined from a mechanically regularized system using the equilibrium gap method, and an additional boundary regularization. It is shown that even if the underlying material behavior is not very well known, this approach leads to extremely small correlation residuals. An excellent stability of the estimated displacement field for noisy (reconstructed) volumes is also observed.     

Experimental distribution of phases and pressure drop in a two-phase offset strip fin type compact heat exchanger

Uniform distribution of fluids is crucial to obtain high performance in compact heat exchangers. Maldistribution has been studied by many authors, especially for parallel channels heat exchangers. But theoretical models and experimental studies for predicting flow maldistribution in offset strip fins exchangers are scarce. Offset strip fins, besides their higher thermal hydraulic performances, favour lateral distribution due to their geometry. In this work, an experimental investigation has been carried out for this type of heat exchanger. The experimental set-up consists in a flat vertical compact heat exchanger (1 m × 1 m area and 7.13 mm thickness) equipped with offset strip fins with a hydraulic diameter of 1.397 mm. Air and water are the working fluids. The flow rates of each phase in seven zones regularly distributed at the outlet have been measured as well as the pressures at the inlet, the outlet and two intermediate positions. These measurements were completed with visualisations using a high-speed camera.     

Synthesis and characterization of 5-octylthieno[3,4-c]pyrrole-4,6-dione derivatives as new monomers for conjugated copolymers

An efficient route for the synthesis of 1-iodo-5-octyl-4H-thieno[3,4-c]pyrrole-4,6(5H)-dione as a key intermediate to build new electron-deficient monomers and related conjugated polymers is reported. Along these lines, two new low bandgap copolymers were synthesized from Stille or Suzuki coupling. These polymers were characterized and their properties compared to those of analogous conjugated polymers.     

An Efficient Preparation of Coumarins

o-methoxyaryl-aldehydes (or -ketones) react in solid-phase with Meldrum's acid under mild conditions, to give benzylidene derivatives which are cyclized in high yield, with cold sulfuric acid to substituted 3-carboxycoumarins. Thermal decarboxylation, speed up by copper powder, provided an easy access to numerous coumarins.     

Conducting polymers: Efficient thermoelectric materials

This review highlights the recent progress made in the area of thermoelectric (TE) applications of conducting polymers and related composites. Several examples of such materials and their TE properties are discussed. TE properties of new poly(2,7‐carbazole) derivatives are highlighted. References are also made to carbon nanotube/polymer composites and their improved electrical and TE performance. Studies on polymer/inorganic materials composites have also taken a step forward and have shown very promising TE properties. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011