Influence of geometry on the giant magnetoimpedance of high-aspect ratio amorphous magnetic ribbons

We study the influence of ribbon geometry on the giant magnetoimpedance (GMI) behavior of both low- and high-aspect ratio [length (l)/width (w) = 2–150] ribbons made from commercially available amorphous magnetic materials. Our results indicate that the variation of the ribbons’ GMI with geometry is due to the combination of edge effects (due to damage created by the ribbon cutting process) and global shape anisotropy. In high-aspect ratio ribbons [length (l)/width (w)≥ 20], we find that the GMI decreases with width, which we suggest is due to the cutting process creating induced stresses that suppress the transverse susceptibility at the edge of the material. In lower aspect ratio ribbons [length (l)/width (w) ≤ 20], shape anisotropy results in a relatively rapid increase in GMI with increasing length. We conclude that, with suitable optimization, high-aspect ratio ribbons prepared from commercially available materials are suitable for use as macro-scale sensors that detect small magnetic fields/strains over a large sensing area

Evaluation of reproducibility of the chemical solubility of dental ceramics using ISO 6872:2015

Statement of problem The current chemical solubility method in the International Standards Organization (ISO) 6872 (2015) specifies only the total surface area of specimens for testing (≥30 cm2) but does not describe the morphology or geometry. This could impact the reproducibility of the test outcomes. Purpose The purpose of this in vitro study was to investigate the factors influencing the reliability of the ISO 6872:2015 “Dentistry-Ceramic materials” test for chemical solubility. Material and methods Chemical solubility analysis of a range of materials and specimen geometries was performed in accordance with ISO 6872:2015. Yttria-stabilized tetragonal zirconia polycrystal (Y-TZP), VITABLOCS Mark II, IPS e.max Press, and IPS e.max ZirPress materials were formed into a range of cubic and spherical geometries to comply with the 30-cm2 minimum surface area requirement. The surface microstructure of the specimens was analyzed using a scanning electron microscope, inductively coupled plasma optical emission spectrometry (ICP-OES) was used to analyze the solutes, and surface hardness of the specimens was measured by using a Vickers hardness tester before and after testing. An optimized solubility test was devised, which eliminated specimen handling once the specimens had been ground and polished. This modified test was performed on VITABLOCS Mark II and Y-TZP. Results The results of the original chemical solubility method of ISO 6872:2015 showed significantly variable findings for each tested material, with a predictable relationship between geometry and chemical solubility. The hardness values decreased significantly after the solubility testing. The optimized method showed significantly improved reproducibility of the chemical solubility measurement compared with the original ISO 6872:2015 test. Conclusions The results of the current chemical solubility standard method can be manipulated while still complying with the ISO 6872:2015 standard

Demonstrating the Potential of Using Bio-Based Sustainable Polyester Blends for Bone Tissue Engineering Applications

YesHealthcare applications are known to have a considerable environmental impact and the use of bio-based polymers has emerged as a powerful approach to reduce the carbon footprint in the sector. This research aims to explore the suitability of using a new sustainable polyester blend (Floreon™) as a scaffold directed to aid in musculoskeletal applications. Musculoskeletal problems arise from a wide range of diseases and injuries related to bones and joints. Specifically, bone injuries may result from trauma, cancer, or long-term infections and they are currently considered a major global problem in both developed and developing countries. In this work we have manufactured a series of 3D-printed constructs from a novel biopolymer blend using fused deposition modelling (FDM), and we have modified these materials using a bioceramic (wollastonite, 15% w/w). We have evaluated their performance in vitro using human dermal fibroblasts and rat mesenchymal stromal cells. The new sustainable blend is biocompatible, showing no differences in cell metabolic activity when compared to PLA controls for periods 1-18 days. FloreonTM blend has proven to be a promising material to be used in bone tissue regeneration as it shows an impact strength in the same range of that shown by native bone (just under 10 kJ/m2) and supports an improvement in osteogenic activity when modified with wollastonite.We would like to acknowledge the Medical Research Council in the UK (MRC) for funding this research throughout a MRC Proximity to Discovery award (P2D) with grant number MC_PC_16084. We would also like to acknowledge CONACYT for funding DH RamosRodriguez’s work

Hardness determination of bio-ceramics using laser-induced breakdown spectroscopy.

Laser-Induced Breakdown Spectroscopy (LIBS) was applied to the analysis of bioceramic samples. The relationship between sample hardness and LIBS plasma properties was investigated, with comparison to conventional Vickers hardness measurements. The plasma excitation temperature Te was determined using the lineto- continuum ratio for the Si (I) 288.16 nm emission line; we have demonstrated a linear relationship between sample surface hardness and plasma temperature. Results indicate that hardness determination based on measurements of Te offers greater reproducibility than Vickers hardness measurements, under the conditions considered here. The validity of spectroscopic diagnostics based on LTE was confirmed