Investigation and Prediction of Tensile, Flexural, and Compressive Properties of Tough PLA Material Using Definitive Screening Design.

The material extrusion fused deposition modeling (FDM) technique has become a widely used technique that enables the production of complex parts for various applications. To overcome limitations of PLA material such as low impact toughness, commercially available materials such as UltiMaker Tough PLA were produced to improve the parent PLA material that can be widely applied in many engineering applications. In this study, 3D-printed parts (test specimens) considering six different printing parameters (i.e., layer height, wall thickness, infill density, build plate temperature, printing speed, and printing temperature) are experimentally investigated to understand their impact on the mechanical properties of Tough PLA material. Three different standardized tests of tensile, flexural, and compressive properties were conducted to determine the maximum force and Young's modulus. These six properties were used as responses in a design of experiment, definitive screening design (DSD), to build six regression models. Analysis of variance (ANOVA) is performed to evaluate the effects of each of the six printing parameters on Tough PLA mechanical properties. It is shown that all regression models are statistically significant (p<0.05) with high values of adjusted and predicted R2. Conducted confirmation tests resulted in low relative errors between experimental and predicted data, indicating that the developed models are adequately accurate and reliable for the prediction of tensile, flexural, and compressive properties of Tough PLA material.

Students' performance in teaching neuroanatomy using traditional and technology-based methods.

The use of digital teaching resources became widespread and very helpful during the COVID-19 pandemic as an alternative to a traditional course with cadavers. Technologies such as augmented reality (AR), virtual reality (VR), 3D models, video lectures and other online resources enable three-dimensional visualization of the anatomical structures and allow students to learn more interactively. The aim of this study was to compare students' performance in the traditional anatomical courses in teaching neuroanatomy and technology-based learning methods such as video lectures, 3D models and 3D printed specimens. Four groups of first-year students of Veterinary Faculty established for the practical classes during the academic year 2021/2022 took part in this research. The total number of students participating in this research was 72. Each group attended separately the theoretical lecture with a demonstration based on a different technique; the control group used formalized specimens, while the three experimental groups used video lectures, 3D models and 3D printed specimens, respectively. Subsequently, all groups completed the same questionnaire testing their short-term memory of the neuroanatomical structures. After four weeks students were tested for their long-term memory of the neuroanatomy lecture with the follow-up test containing an identical list of questions. The test scores using video lectures and 3D printed models were significantly higher compared with the group that learned in the traditional way. This study suggests that alternative approaches such as technology-based digital methods can facilitate memorization of anatomical terms and structures in a more interactive and sensory engaging way of learning.

Utilisation of 3D Printing in the Manufacturing of an Anthropomorphic Paediatric Head Phantom for the Optimisation of Scanning Parameters in CT.

Computed tomography (CT) is a diagnostic imaging process that uses ionising radiation to obtain information about the interior anatomic structure of the human body. Considering that the medical use of ionising radiation implies exposing patients to radiation that may lead to unwanted stochastic effects and that those effects are less probable at lower doses, optimising imaging protocols is of great importance. In this paper, we used an assembled 3D-printed infant head phantom and matched its image quality parameters with those obtained for a commercially available adult head phantom using the imaging protocol dedicated for adult patients. In accordance with the results, an optimised scanning protocol was designed which resulted in dose reductions for paediatric patients while keeping image quality at an adequate level.