The effect of CuO addition on the phase composition of clinker and the Cu incorporation into the structure of clinker phases was monitored under laboratory conditions. Separate synthesized CuO‐doped ...clinker phases as well as clinkers with different CuO content up to 4 wt.% were characterized by XRD, optical and electron microscopy with EDS analysis. It has been found that Cu tends to form a separate phase or a double oxide with Ca and incorporates in the clinker phases to a limited extent, except for C4AF. With increasing CuO content in clinker, its phase composition changes, and the size of alite crystals increases.
OBJECTIVESNational guidelines for routine pediatric acute asthma care recommend providing corticosteroids, and discourage routinely obtaining chest radiographs (CXRs) and using antibiotics. We ...examined rates of adherence to all 3 of these aspects during emergency department (ED) visits and compared performance between pediatric and general EDs.
METHODSUsing the National Hospital Ambulatory Medical Care Survey, we included all nontransfer ED visits for patients younger than 19 years with a diagnosis of asthma and treatment with albuterol from 2005 to 2015. Guideline-based care, defined as (1) corticosteroids, (2) no antibiotics, and (3) no CXR, was assessed for each visit. Hospitals were categorized as pediatric or general and compared according to rates of guideline-based care. Multivariable analyses were used to identify demographic and hospital-level characteristics associated with guideline-based care.
RESULTSMore than 7 million ED visits met eligibility criteria. Antibiotic provision and CXR acquisition were significantly higher in general EDs (20% vs 11%, 40% vs 26%, respectively), while steroid provision was similar (63% vs 62%). Overall, 34% of visits involved guideline-based care, with a higher rate for pediatric EDs compared with general EDs (42% to 31%). Visit at a pediatric ED (odds ratio, 1.62 confidence interval 1.17–2.25) and black race (odds ratio, 1.48 confidence interval 1.07–2.02) were independently associated with guideline-based care in a multivariate analysis.
CONCLUSIONSGuideline-based care was more common in pediatric EDs, although only one-third of all pediatric-age visits met the definition of guideline-based care. Future policy and education efforts to reduce unnecessary antibiotic and CXR use for children with asthma are warranted.
Abstract Zinc oxide (ZnO) was prepared by the sol-gel method as thin films deposited using spray pyrolysis. The characterization of the synthesized ZnO has been carried out using x-ray diffraction ...(XRD), Fourier-transform infrared (FTIR), scanning electron microscopy (SEM), and UV-Visible absorption spectroscopy. The experimental results revealed that the prepared ZnO has a wurtzite hexagonal structure with an average crystallite size of about 26.7 nm. High purity and flake-like structures were achieved as SEM and energy dispersive indicated. FTIR confirmed the prepared ZnO’s high purity as the Zn-O stretching peak was very intense. The optical parameters were comprehensively investigated, including absorption, reflection, extinction coefficient, refractive index, and optical energy gap. The wurtzite hexagonal structure of ZnO was optimized using the local-density approximation with the Hubbard correction method (LDA+U). Our experimental result for the energy gap is 3.28 (eV), which is in excellent agreement with the first principle calculations. We utilize the results from the LDA+U calculation along with our experimental outcomes to calculate the thickness of the thin film in UV-Vis spectroscopy.
In this study, two similar, commercial polycrystalline Ni-based disk superalloys (LSHR and ME3) were creep tested at 760 °C and 552 MPa to approximately 0.3% plastic strain. LSHR consistently ...displayed superior creep properties at this stress/temperature regime even though the microstructural characteristics between the two alloys were comparable. High resolution structural and chemical analysis, however, revealed significant differences between the two alloys among active γ′ shearing modes involving superlattice intrinsic and extrinsic stacking faults. In ME3, Co and Cr segregation and Ni and Al depletion were observed along the intrinsic faults - revealing a γ′ to γ phase transformation. Conversely in LSHR, an alloy with a higher W content, Co and W segregation was observed along the intrinsic faults. This observation combined with scanning transmission electron microscopy (STEM) simulations confirm a γ′-to-D019 χ phase transformation along the intrinsic faults in LSHR. Using experimental observations and density functional theory calculations, a novel local phase transformation strengthening mechanism is proposed that could be further utilized to improve the high temperature creep capabilities of Ni-base disk alloys.
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