51 research outputs found
Evidence of Gd substitution for Y in YBCO films with Gd excess
Gd-YBaCuO (Gd-YBCO) thin films with 10 mol% and 20 mol% excess-Gd concentration with respect to Y were investigated at the Gd L and Y K core absorption edges by EXAFS spectroscopy with the aim of determining
the local structure of the Gd dopant. To this purpose, EXAFS data were collected also on Gd-BaCuO (GdBCO) and pristine YBCO films and on GdO and YO model compounds for comparison with the YBCO films with Gd excess. The EXAFS analysis was based on Y and Gd oxides as well as on a cluster obtained by Density Functional Theory (DFT) where Gd atoms were inserted substitutional to Y atoms. The EXAFS data clearly reveal the incorporation of Gd in the lattice as substitute of Y and no evidence of segregated Gd oxide was found within the film matrix
Evidence of Gd substitution for Y in YBCO films with Gd excess
Gd-YBa2Cu3O7-δ (Gd-YBCO) thin films with 10 mol% and 20 mol% excess-Gd concentration with respect to Y were investigated at the Gd L3 and Y K core absorption edges by EXAFS spectroscopy with the aim of determining the local structure of the Gd dopant. To this purpose, EXAFS data were collected also on GdBa2Cu3O7-δ (GdBCO) and pristine YBCO films and on Gd2O3 and Y2O3 model compounds for comparison with the YBCO films with Gd excess. The EXAFS analysis was based on Y and Gd oxides as well as on a cluster obtained by Density Functional Theory (DFT) where Gd atoms were inserted substitutional to Y atoms. The EXAFS data clearly reveal the incorporation of Gd in the lattice as substitute of Y and no evidence of segregated Gd oxide was found within the film matrix
Investigation of the crystallization process of CSD-ErBCO on IBAD-substrate via DSD approach
REBaCuO (REBCO, RE: rare earth, such as Y and Gd) compounds have been extensively studied as a superconducting layer in coated conductors. Although ErBCO potentially has better superconducting properties than YBCO and GdBCO, little research has been made on it, especially in chemical solution deposition (CSD). In this work, ErBCO films were deposited on IBAD (ion-beam-assisted-deposition) substrates by CSD with low-fluorine solutions. The crystallization process was optimized to achieve the highest self-field critical current density (J) at 77 K. Commonly, for the investigation of a CSD process involving numerous process factors, one factor is changed keeping the others constant, requiring much time and cost. For more efficient investigation, this study adopted a novel design-of-experiment technique, definitive screening design (DSD), for the first time in CSD process. Two different types of solutions containing Er-propionate or Er-acetate were used to make two types of samples, Er-P and Er-A, respectively. Within the investigated range, we found that crystallization temperature, dew point, and oxygen partial pressure play a key role in Er-P, while the former two factors are significant for Er-A. DSD revealed these significant factors among six process factors with only 14 trials. Moreover, the DSD approach allowed us to create models that predict J accurately. These models revealed the optimum conditions giving the highest J values of 3.6 MA/cm for Er-P and 3.0 MA/cm for Er-A. These results indicate that DSD is an attractive approach to optimize CSD process
Impact of a Primary Care Antimicrobial Stewardship Program on Bacterial Resistance Control and Ecological Imprint in Urinary Tract Infections
Antimicrobial stewardship programs (ASPs) are a central component in reducing the overprescription of unnecessary antibiotics, with multiple studies showing benefits in the reduction of bacterial resistance. Less commonly, ASPs have been performed in outpatient settings, but there is a lack of available data in these settings. We implemented an ASP in a large regional outpatient setting to assess its feasibility and effectiveness. Over a 5-year post-implementation period, compared to the pre-intervention period, a significant reduction in antibiotic prescription occurred, with a reduction in resistance in E. coli urinary isolates. ASP activities also were found to be cost-effective, with a reduction in medication prescription
Rheological and microstructural properties of sepiolite gels. Influence of the addition of ionic surfactants
Comparison of different CSD-grown REBCO (RE = Yb, Er, Ho, Y, Dy, Gd, Sm, Nd) compounds with respect to applicability as Coated Conductors
In-situ precipitation of BaHfO3 nanoparticles in REBCO films deposited by TFA-MOD on LZO/CeO2-buffered Ni-5at%W tapes via reel-to-reel process
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