Feasibility of Unwaxed and Waxed Banana (Musa acuminata x balbisiana) Pseudostem Fibers as Alternative Dental Floss Material

Oral health, waste management, and sustainability are prevalent issues faced by developing countries. Relative to these concerns, there remains a need for oral hygiene essentials that are both effective and environmentally responsible. This study aims to explore the feasibility of banana pseudostem fibers (BPF) as an alternative material for sustainable dental floss in terms of two physical properties, namely, tensile strength and elongation at break. Fibers were mechanically extracted from the outermost sheaths of banana pseudostems to produce two sample groups, unwaxed BPF and waxed BPF, the latter comprising fibers that were coated with a mixture of two parts coconut oil and one part candelilla wax. Both sample groups were tested for tensile strength and elongation at break. According to the mean and SD of both groups and one-way MANOVA, unwaxed BPF had significantly higher tensile strength and elongation at break than waxed BPF, revealing that the wax coating process diminished the physical properties of the BPF due to thermal degradation. Furthermore, the application of the coconut oil-candelilla wax coating was found to have a large effect on tensile strength and a small effect on elongation at break. Results show that there is potential in BPF to be an alternative material for dental floss in relation to the examined properties, although it may not be a substitute for synthetic dental floss material by itself. Modifying the fiber extraction and wax coating processes involved and assessing the chemical properties of the material are also recommended for further research

Coronal Heating as Determined by the Solar Flare Frequency Distribution Obtained by Aggregating Case Studies

Flare frequency distributions represent a key approach to addressing one of the largest problems in solar and stellar physics: determining the mechanism that counter-intuitively heats coronae to temperatures that are orders of magnitude hotter than the corresponding photospheres. It is widely accepted that the magnetic field is responsible for the heating, but there are two competing mechanisms that could explain it: nanoflares or Alfv\'en waves. To date, neither can be directly observed. Nanoflares are, by definition, extremely small, but their aggregate energy release could represent a substantial heating mechanism, presuming they are sufficiently abundant. One way to test this presumption is via the flare frequency distribution, which describes how often flares of various energies occur. If the slope of the power law fitting the flare frequency distribution is above a critical threshold, $\alpha=2$ as established in prior literature, then there should be a sufficient abundance of nanoflares to explain coronal heating. We performed $>$600 case studies of solar flares, made possible by an unprecedented number of data analysts via three semesters of an undergraduate physics laboratory course. This allowed us to include two crucial, but nontrivial, analysis methods: pre-flare baseline subtraction and computation of the flare energy, which requires determining flare start and stop times. We aggregated the results of these analyses into a statistical study to determine that $\alpha = 1.63 \pm 0.03$. This is below the critical threshold, suggesting that Alfv\'en waves are an important driver of coronal heating.Comment: 1,002 authors, 14 pages, 4 figures, 3 tables, published by The Astrophysical Journal on 2023-05-09, volume 948, page 7