14 research outputs found

    Inkjet Printing Infiltration of the Doped Ceria Interlayer in Commercial Anode-Supported SOFCs.

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    Single-step inkjet printing infiltration with doped ceria Ce0.9Ye0.1O1.95 (YDC) and cobalt oxide (CoxOy) precursor inks was performed in order to modify the properties of the doped ceria interlayer in commercial (50 × 50 × 0.5 mm3 size) anode-supported SOFCs. The penetration of the inks throughout the La0.8Sr0.2Co0.5Fe0.5O3-δ porous cathode to the Gd0.1Ce0.9O2 (GDC) interlayer was achieved by optimisation of the inks' rheology jetting parameters. The low-temperature calcination (750 °C) resulted in densification of the Gd-doped ceria porous interlayer as well as decoration of the cathode scaffold with nanoparticles (~20-50 nm in size). The I-V testing in pure hydrogen showed a maximum power density gain of ~20% at 700 °C and ~97% at 800 °C for the infiltrated cells. The latter effect was largely assigned to the improvement in the interfacial Ohmic resistance due to the densification of the interlayer. The EIS study of the polarisation losses of the reference and infiltrated cells revealed a reduction in the activation polarisations losses at 700 °C due to the nano-decoration of the La0.8Sr0.2Co0.5Fe0.5O3-δ scaffold surface. Such was not the case at 800 °C, where the drop in Ohmic losses was dominant. This work demonstrated that single-step inkjet printing infiltration, a non-disruptive, low-cost technique, can produce significant and scalable performance enhancements in commercial anode-supported SOFCs

    Implementation of metal-free ring-opening polymerization in the preparation of aliphatic polycarbonate materials

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    Environmental concerns along with the need to develop aliphatic polycarbonate materials free of any toxic compounds have driven scientists to implement macromolecular engineering processes by replacing potentially toxic and carcinogenic metal-based catalysts traditionally used for the ring-opening polymerization of cyclic carbonates by organic compounds. This issue is of particular importance as aliphatic polycarbonates are gaining increasing credibility for biomedical applications owing to their biocompatibility and bioresorbability. This review provides a complete account of the various metal-free catalysts that has been developed so far as well as comprehensive investigations on the related polymerization mechanisms

    PROCESS FOR CONTROLLED DEGRADATION OF POLYHYDROXYALKANOATES AND PRODUCTS OBTAINABLE THEREFROM

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    The present invention relates to a process for producing polyhydroxyalkanoate oligomers and/or polymers of reduced molecular weight, which comprises reacting at least one polyhydroxyalkanoate (PHA) with at least one carbonate salt at a temperature of from 50 DEG C to 300 DEG C, preferably from 120 DEG C to 200 DEG C. The above reaction allows a controlled degradation of the PHA chains which yields oligomers and/or polymers having a controlled molecular weight, which can be modulated in view of the specific application for which the oligomers and/or polymers are intended. Moreover, during the reaction carbon dioxide evolves which produces a foamed material which can be easily processed on an industrial scale.; Additionally, the above oligomers and/or polymers, having an end-group bearing a double bond C=C, particularly a crotonate end-group for PHB, can be subjected to subsequent modifications to obtain a wide variety of functional end-groups, for instance carboxyl, carboxylate, hydroxyl, dihydroxyl, oxirane ring, halogen atom. Moreover, the low molecular weight PHAs may be used in the area of controlled delivery systems in agro-chemistry, in the cosmetic industry, in medicine in the form of nano- or microspheres, in household products and in coating systems

    METHOD OF CONTROLLING THERMAL DEGRADATION OF ANIONICALLY TERMINATED POLYMERS AND MATERIALS OBTAINED

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    The invention relates to a polymer having improved thermal stability and to a method for preparing said polymer that enables control of its thermal degradation and stability via chemical structure of the polymer end groups. Further the invention relates to a blend comprising said polymer. Finally, the invention relates to use of said polymer or blend for the preparation of polymeric materials for applications in medical, environmental, agricultural and advance materials

    Attitude of Healthcare Professionals: A Major Limiting Factor in Organ Donation from Brain-Dead Donors

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    Public attitude toward deceased donor organ recovery in Poland is quite positive, with only 15% opposing to donation of their own organs, yet actual donation rate is only 16/pmp. Moreover, donation rate varies greatly (from 5 to 28 pmp) in different regions of the country. To identify the barriers of organ donation, we surveyed 587 physicians involved in brain death diagnosis from regions with low (LDR) and high donation rates (HDR). Physicians from LDR were twice more reluctant to start diagnostic procedure when clinical signs of brain death were present (14% versus 5.5% physicians from HDR who would not diagnose death, resp.). Twenty-five percent of LDR physicians (as opposed to 12% of physicians from HDR) would either continue with intensive therapy or confirm brain death and limit to the so-called minimal therapy. Only 32% of LDR physicians would proceed with brain death diagnosis regardless of organ donation, compared to 67% in HDR. When donation was not an option, mechanical ventilation would be continued more often in LDR regions (43% versus 26.7%; < 0.01). In conclusion, low donation activity seems to be mostly due to medical staff attitude
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