33 research outputs found
The Al-Rich Part of the Fe-Al Phase Diagram
The Al-rich part of the Fe-Al phase diagram between 50 and 80 at.% Al including the complex intermetallic phases FeAl (ε), FeAl, FeAl, and Fe4Al was re-investigated in detail. A series of 19 alloys was produced and heat-treated at temperatures in the range from 600 to 1100 °C for up to 5000 h. The obtained data were further complemented by results from a number of diffusion couples, which helped to determine the homogeneity ranges of the phases FeAl, FeAl, and FeAl. All microstructures were inspected by scanning electron microscopy (SEM), and chemical compositions of the equilibrium phases as well as of the alloys were obtained by electron probe microanalysis (EPMA). Crystal structures and the variation of the lattice parameters were studied by x-ray diffraction (XRD) and differential thermal analysis (DTA) was applied to measure all types of transition temperatures. From these results, a revised version of the Al-rich part of the phase diagram was constructed
Investigation of the Ni3Al-Fe alloys by resistivity measurements and differential thermal analysis
Relative Importance of Crack Propagation and Crack Nucleation in the Ductile Fracture of FeCo-2% V
Exercise-induced bronchospasm: implications for patients with or without asthma in primary care practice
Stuart W Stoloff1, Gene L Colice2, Mary Lou Hayden3, Timothy J Craig4, Nancy K Ostrom5, Nemr S Eid6, Jonathan P Parsons71University of Nevada School of Medicine, Reno, NV, 2Washington Hospital Center, Washington, DC, 3University of Virginia, Charlottesville, VA, 4Pennsylvania State University, Hershey, PA, 5Allergy and Asthma Medical Group and Research Center, San Diego, CA, 6University of Louisville, Louisville, KY, 7Ohio State University Asthma Center, Columbus, OH, USAAbstract: Exercise-induced bronchospasm (EIB) can represent a substantial barrier to physical activity. We present the cases of two patients with EIB, one with asthma, and one without asthma, who were evaluated at our primary care practice. The first case was a 44-year-old man with a history of seasonal allergic rhinitis but no asthma, who reported difficulty breathing when playing tennis. The second case was a 45-year-old woman who presented with persistent, generally well-controlled asthma, who was now experiencing bouts of coughing and wheezing during exercise. In both cases, an exercise challenge was used to diagnose EIB, and patients were prescribed a short-acting beta agonist to be used immediately before initiating exercise. EIB is a frequently encountered problem among patients presenting to primary care specialists. Affected patients should be made aware of the importance of proactive treatment with a short-acting beta agonist before initiating any exercise.Keywords: asthma, compliance, exercise-induced bronchospas