Acute Cr VI water pollution duet oa nthropogenic activities is an increasing worldwide concern. The high toxicity and mobility of Cr VI makesi tn ecessary to develop dual adsorbent/ion-reductive materialst hat are able to capture Cr VI and transform it efficiently into the less hazardous Cr III. An accurated escription of chromium speciationa tt he adsorbent/ion-reductive matrix is key to assessing whether Cr VI is completely reduced to Cr III ,o ri fi ts incomplete transformation has led to the stabilization of highly reactive, transient Cr V species within the material. With this goal in mind, a dual ultraviolet-visible and electron paramagnetic spectroscopy approachh as been applied to determine the chromium speciation within zirconium-basedm etal-organic frameworks (MOFs). Our findings point out that the generation of defects at Zr-MOFs boosts Cr VI adsorption, whilst the presence of reductiveg roups on the organic linkersp lay ak ey role in stabilizing it as isolated and/or clustered Cr III ions.

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Poly(L-lactide)/reduced Graphene oxide (PLLA/rGO) scaffolds were studied in the present work.The scaffolds were fabricated by TIPS (thermally induced phase separation). Nonisothermal crystallization study for PLLA/rGO was investigated and revealed the nucleating effect of rGO. rGO effect on cytotoxicity, thermal properties, and hydrolysis resistance of PLLA and PLLA/rGO scaffolds were analysed. In vitro degradation in phosphate-buffered solution at 37 ºC is analyzed over twelve weeks. A high crystalline behaviour reduces the speed of hydrolysis and therefore implies less variation in pH, mass loss and water up take. The rGO does not seem to accelerate the degradation process. Finally, rGO contents in PLLA up to 1 wt% dos not lead to cytotoxic effect, the scaffolds supporting cell adhesion and proliferation.

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The machining of a central axial hole in a duplex stainless steel 2205 bar is sufficient to optimize cooling and thus to achieve the toughness requirements of the most demanding international standards. The cooling rates are obtained by finite element methodology simulation. The increased cooling rate in the central zone of the bar is directly related to the improvement of the Charpy impact toughness. Microstructure at different bar locations is characterized by optical microscopy, scanning electron microscopy, and energy‐dispersive X‐ray spectrometry. In the absence of sigma phase precipitation, an austenite spacing over 45 μ provokes a decrease in absorbed energy close to 40 J. Moreover, the pierced bar complies with the international standards requirements in tensile with yield strength higher than 450 MPa and Rockwell hardness lower than 31 (HRC) over the section and along the bar. Finally, the resistance to pitting corrosion required is also satisfactory due to the absence of chromium nitrides.