Thermal and Mechanical Properties of Reprocessed Polylactide/Titanium Dioxide Nanocomposites for Material Extrusion Additive Manufacturing.

Polylactic acid (PLA) is a biodegradable polymer that can replace petroleum-based polymers and is widely used in material extrusion additive manufacturing (AM). The reprocessing of PLA leads to a downcycling of its properties, so strategies are being sought to counteract this effect, such as blending with virgin material or creating nanocomposites. Thus, two sets of nanocomposites based respectively on virgin PLA and a blend of PLA and reprocessed PLA (rPLA) with the addition of 0, 3, and 7 wt% of titanium dioxide nanoparticles (TiO) were created via a double screw extruder system.

Manufacture and Characterization of Polylactic Acid Filaments Recycled from Real Waste for 3D Printing.

This paper studies the thermal, morphological, and mechanical properties of 3D-printed polylactic acid (PLA) blends of virgin and recycled material in the following proportions: 100/0, 25/75, 50/50, and 75/25, respectively. Real waste, used as recycled content, was shredded and sorted by size without a washing step. Regular dog-bone specimens were 3D printed from filaments, manufactured in a single screw extruder.

Effect of Thermal and Hydrothermal Accelerated Aging on 3D Printed Polylactic Acid.

In the new transformation of 'Industry 4.0', additive manufacturing technologies have become one of the fastest developed industries, with polylactic acid (PLA) playing a significant role. However, there is an increasing amount of garbage generated during the printing process and after prototypes or end-of-life parts.

Bismuth incorporation and the role of ordering in GaAsBi/GaAs structures.

The structure and composition of single GaAsBi/GaAs epilayers grown by molecular beam epitaxy were investigated by optical and transmission electron microscopy techniques. Firstly, the GaAsBi layers exhibit two distinct regions and a varying Bi composition profile in the growth direction. In the lower (25 nm) region, the Bi content decays exponentially from an initial maximum value, while the upper region comprises an almost constant Bi content until the end of the layer.

Impact of N on the atomic-scale Sb distribution in quaternary GaAsSbN-capped InAs quantum dots.

The use of GaAsSbN capping layers on InAs/GaAs quantum dots (QDs) has recently been proposed for micro- and optoelectronic applications for their ability to independently tailor electron and hole confinement potentials. However, there is a lack of knowledge about the structural and compositional changes associated with the process of simultaneous Sb and N incorporation. In the present work, we have characterized using transmission electron microscopy techniques the effects of adding N in the GaAsSb/InAs/GaAs QD system.

Calculation of integrated intensities in aberration-corrected Z-contrast images.

Inclusion of spatial incoherence has been shown to give quantitative agreement between non-aberration-corrected high-angle annular dark-field scanning transmission electron microscopy images and theoretical simulations. Here we show that, using the same approach, a significant improvement in the correlation between calculated and experimental normalized integrated intensities is obtained in the InAsP ternary semiconductor alloy, but residual discrepancies remain. We have demonstrated, in good agreement with experimental intensities obtained in calibrated samples, that normalized integrated intensities show a low dependence on the sample thickness over a wide range of thickness values.

Blueprinting for clinical performance deficiencies--lessons and principles from the General Medical Council's fitness to practise procedures.

Background: The UK General Medical Council (GMC) in its regulatory capacity conducts formal tests of competence (TOCs) on doctors whose performance is of concern. TOCs are individually tailored to each doctor's specialty and grade.

Aims: To describe the development and implementation of an electronic blueprinting system that supports the delivery of TOCs.

The development of a new method of knowledge assessment: tailoring a test to a doctor's area of practice.

The practice of clinical medicine is becoming increasingly specialized, and this change has increased the challenge of developing fair, valid, and reliable tests of knowledge, particularly for single candidates or small groups of candidates. The problem is particularly relevant to the UK's General Medical Council's Fitness to Practice procedures, which investigate individual doctors. In such cases, there is a need for an alternative to the conventional approach to reliability estimation that will still allow the delivery of reproducible and standardized tests.

A method to determine the strain and nucleation sites of stacked nano-objects.

We determine the compositional distribution with atomic column resolution in a horizontal nanowire from the analysis of aberration-corrected high resolution Z-contrast images. The strain field in a layer capping the analysed nanowire is determined by anisotropic elastic theory from the resulting compositional map. The reported method allows preferential nucleation sites for epitaxial nanowires to be predicted with high spatial resolution, as required for accurate tuning of desired optical properties.

Using computers for assessment in medicine.

Computer based testing can offer many advantages over traditional paper based methods of assessment. The authors look at what it means and its potential uses for assessment in medicine

A randomized, double blind, dose-response comparison of balsalazide (6.75 g), balsalazide (2.25 g), and mesalamine (2.4 g) in the treatment of active, mild-to-moderate ulcerative colitis.

Objective: Balsalazide is a new innovative, mesalamine-containing prodrug that is activated by bacteria in the colon. Balsalazide has been shown previously to be well tolerated and effective in the treatment of acute ulcerative colitis. The aim of this study was to determine the dose-response of balsalazide for efficacy and safety in active, mild-to-moderate ulcerative colitis and to compare this profile with that of mesalamine, pH-dependent, delayed-release tablets.