Standards, Volume 1, Issue 1 (September 2021) – 6 articles

Total hip metal arthroplasty (THA) constitutes an important proportion of the standard clinical hip implant usage in Medical Physics and Biomedical Engineering. A computational nonlinear optimization is performed with two commonly metal materials in Metal-on-Metal (MoM) THA. Namely, Cast Co-Cr Alloy and Titanium. The principal result is the numerical determination of the K adimensional-constant parameter of the model. Results from a new more powerful algorithm than previous contributions, show significant improvements. Numerical standard figures for dual optimization give acceptable model-parameter values with low residuals. These results are demonstrated with 2D and 3D Graphical/Interior Optimization also. According to the findings/calculations, the standard optimized metal-model parameters are mathematically proven and verified. Mathematical consequences are obtained for model improvements and in vitro simulation methodology. The wear magnitude for in vitro determinations with these model parameter data constitute the innovation of the method. In consequence, the erosion prediction for laboratory experimental testing in THA adds valuable information to the literature. Applications lead to medical physics improvements for material/metal-THA designs. Full article

Next Generation Science Standards science and engineering practices (NGSS S&E) are ways of eliciting reasoning and applying foundational ideas in science. Studies have revealed one major impediment to implementing the NGSS, namely, insufficient teacher preparation, which is a concern at all teaching levels. The present study examined a program grounded in research on how students learn science and engineering pedagogical content knowledge and strategies for incorporating NGSS S&E practices into instruction. The program provided guided teaching practice, content learning experiences in the physical sciences, engineering design tasks, and extended projects. Research questions included: To what extent did the Program increase teachers’ competence and confidence in science content, with emphasis on science and engineering practices? To what extent did the program increase teachers’ use of reformed teaching practices? This mixed-methods, quasi-experimental design examined teacher outcomes in the program for 24 months. The professional development (PD) findings revealed significant increases in teachers’ competence and confidence in integrating science and engineering practices in the classroom. These findings and their specificity contribute to current knowledge and can be utilized by districts in selecting PD to support teachers in preparing to implement the NGSS successfully. Full article

When dealing with powders, a fundamental knowledge of their physical parameters is indispensable, with different methods and approaches proposed in literature. Results obtained differ widely and it is important to define standards to be applied, both toward the methods of investigation and the interpretation of experimental results. The present research intends to propose such standards, while defining general rules to be respected. Firstly, the problem of defining the particle size is inspected. It was found that describing the size of a particle is not as straightforward as one might suspect. Factors of non-sphericity and size distributions make it impossible to put ‘size’ in just one number. Whereas sieving can be used for coarser particles of a size in excess of about 50 µm, instrumental techniques span a wide size range. For fine particles, the occurrence of cohesive forces needs to be overcome and solvents, dispersants and sample mixing need to be applied. Secondly, the shape of the particles is examined. By defining sphericity, irregularly shaped particles are described. Finally, the density of particles, of particle assemblies and their voidage (volume fraction of voids) and the different ways to investigate them are explored. Full article

The International System of Quantities has to be used by scientific and engineering journals as well as by authors of their articles, conference papers, and corresponding books, especially textbooks. This paper describes the historical development and the state of the art of international communications in science, engineering, technology, production, and sustainable development. The International System of Quantities (ISQ) which systematically elaborated on the standards of the International Organization for Standardization and International Electrotechnical Commission on quantities and units (ISO/IEC 80000) still needs to be generally accepted and used. The list of standardized base and derived quantities with their symbols, and rules for terminology of other quantities are presented. In addition, names and symbols of base, derived, and “compound” units for these quantities are given. The most frequent mistakes and some recommendations about the use of quantities, units, prefixes, quantity value expressions, numbers, and symbols of chemical elements are shown, too. The standards shall be available in open access. The lack of standardized quantities regarding science, engineering, and economics is drawn to attention. Further development of the international systems of quantities and units could bring substantial synergies worldwide. Full article