Cast Intermetallic Alloys and Composites Based on Them by Combined Centrifugal Casting—SHS Process
This work aims to establish a scientific and engineering background in the production of cast multicomponent alloys and metalmartix composite (MMCs) via Self-Propagating High Temperature Synthesis (SHS, combustion synthesis) which is a novel process technique regarding fast and low-cost production ability. We carried out the search for reactive systems and process parameters that would ensure preparation of cast multicomponent materials in a single process. The principles and methods of the SHS thermite-type reaction processes have been investigated under high-gravity values applying loads up to 1000 g with special centrifuge set-up. In this way we expected to improve the yield of target product, remove gaseous byproducts, diminish the grain size in the product, and make product composition more uniform. The obtained results can be expected to make a theoretical background for industrial-scale manufacturing of heat-resistant intermetallic alloys, master alloys, catalysts, MMCs etc.
High Temperature Materials Based on the Intermetallic Compound NiAl Reinforced by Refractory Metals for Advanced Energy Conversion Technologies
Advanced NiAl‐based high temperature materials are developed and characterized for structural applications in energy conversion systems. The intermetallic compound NiAl with B2 superlattice structure exhibits superior physical and high temperature mechanical properties, and excellent oxidation resistance. Disadvantages of polycrystalline pure NiAl are the lack in plasticity and fracture toughness at room temperature and insufficient high temperature strength at temperatures above 800 °C. The refractory metals Cr, Mo, and Re form with NiAl quasi‐binary eutectic systems which enable to produce metal fibres reinforced NiAl‐based alloys in the as‐cast condition and by performing directional solidification. These in‐situ composites show fine‐grained and thermally stable microstructures possessing high temperature strength, superior creep resistance and sufficient room temperature ductility.
Perceived job importance and job performance satisfaction of selected clinical nutrition management responsibilities.
A nationwide survey of clinical nutrition managers was conducted to assess perceived importance of selected job responsibilities and perceived performance satisfaction of those job responsibilities. A questionnaire was developed to achieve the study objectives, validated by an expert panel, and pilot-tested prior to data collection. All members of the American Dietetic Association's Clinical Nutrition Management dietetic practice group (N=1,668) were asked to rate the importance of selected job responsibilities and their satisfaction with those responsibilities using Likert-type scales with descriptions. Results revealed that clinical nutrition managers perceived all job responsibilities listed in the questionnaire to be important (ie, the mean score of each responsibility was >3.0 of a 4.0 scale). Respondents rated regulatory-related job responsibilities as most important and were most satisfied with their performance of these responsibilities. Following regulatory-related responsibilities, clinical nutrition managers perceived patient satisfaction and staff retention to be more important than other responsibilities. In general, clinical nutrition managers were more satisfied with their job performance for job responsibilities that they ranked as more important.