Designing a personal informatics system for users without experience in self-tracking: a case study

Thanks to the advancements in ubiquitous and wearable technologies, Personal Informatics (PI) systems can now reach a larger audience of users. However, it is not still clear whether this kind of tool can fit the needs of their daily lives. Our research aims at identifying specific barriers that may prevent the widespread adoption of PI and finding solutions to overcome them. We requested users without competence in self-tracking to use different PI instruments during their daily practices, identifying five user requirements by which to design novel PI tools. On such requirements, we developed a new system that can stimulate the use of these technologies, by enhancing the perceived benefits of collecting personal data. Then, we explored how naïve and experienced users differently explore their personal data in our system through a user trial. Results showed that the system was successful at helping individuals manage and interpret their own data, validated the usefulness of the requirements found and inspired three further design opportunities that could orient the design of future PI systems.     

Determination of the percentage of wood failure by 3D scanning of the adhesive bondline

The quality of the wood-adhesive bond is usually determined by its shear strength and the percentage of wood failure, the latter usually being determined by visual evaluation and prone to the examiner’s subjective evaluation. A new technique of 3D scanning was used to evaluate the percentage of wood failure, and the results obtained were compared to those obtained by means of existing methods, i.e. the visual evaluation and image analysis techniques. Evaluation by 3D scanning showed comparable values for samples with a high percentage of wood failure, but large differences in the case of samples showing mainly adhesive failure.     

Nanostructured Silicon Oxide–Nickel Oxide Sol–Gel Films with Enhanced Optical Carbon Monoxide Gas Sensitivity

Sol–gel derived silica (SiO₂) films doped with nickel oxide (NiO) nanocrystals were fabricated. A bifunctional ligand was used, bearing amine groups capable of coordinating the nickel ions and hydrolysable siloxane groups for anchoring the metal complex moiety to the silicate matrix. Nickel oxide nanocrystals precipitated at 500°C while the film was still porous. The nanocomposite films showed a reversible change in the optical transmittance in the VIS-NIR range when exposed to carbon monoxide gas. The effects of residual porosity, testing temperature, and carbon monoxide gas concentration on optical transmittance were studied.     

Adhesive bonding of 3D-printed ABS parts and wood

Additive manufacturing, also known as 3D printing technology, has experienced massive growth in the last decade. Instead of printing the entire product, 3D printing can be used to produce only the most complex parts, which are then combined with simple, non-printed parts from other materials to make the final product. In addition to mechanical connections, adhesive bonding is most commonly used to combine printed parts with other elements. In this study, the influence of 3D-printing parameters on the bond shear strength of 3D-printed Acrylonitrile-butadiene-styrene copolymer parts bonded to beech wood was investigated. Three printing settings with different layer thicknesses (0.39, 0.19, 0.09 mm) and a posttreatment method that utilized acetone vapour were used. The three different adhesives applied were commercial one-component polyurethane adhesive, hot melt adhesive for edge bonding, and a two-component polyurethane adhesive. The results show that the type of adhesive had the biggest influence on the strength of the bond. The highest bond strength was achieved using a two-component polyurethane adhesive. The type of failure (failure in wood, plastic, adhesive, or cohesive failure) depended greatly on the type of adhesive and thickness of the printed layer.     

Microstructural study of aged ferrite powders for sensing layers

Nanosized powders of La_0.80Sr_0.20Fe_0.95Cu_0.05O_3?w were investigated in terms of structural, morphological, chemical and surface properties by using several characterization techniques. The XPS and IR measurements showed the presence of surface hydroxide and carbonates species. After calcination of the powders at 900 °C the amount of carbonates decreased but was still significant. The sensing activity of thick film based on La_0.80Sr_0.20Fe_0.95Cu_0.05O_3?w was tested as a function of relative humidity and the results indicate that (i) after one year of ambient storage the sensing material lost quite completely its sensitivity to humidity, (ii) the sensing activity of the film was mostly re-activated after a thermal treatment at 900 °C for 2 h, and (iii) the huge shift of the detection limit to low RH caused by the presence of 5 mol% Cu is also restored.     

Erosion behavior of EB-PVD 7YSZ coatings under corrosion/erosion regime: Effect of TBC microstructure and the CMAS chemistry

Aero-engines operating in dust-laden environments often encounter a lot of dust/sand that causes a severe problem to the TBCs by means of erosion. As the turbine entry temperatures are rising, molten sand is also a big concern to the life-time of TBCs.This paper deals with the TBC behavior under the combined influence of erosion and corrosion attack. Variations in TBC morphology, CMAS infiltration time and CMAS composition and their influence on the erosion resistance at room temperature were investigated. Two different EB-PVD 7YSZ morphologies consisting of a different porosity arrangement were tested in the erosion/corrosion regime. The more ‘Feathery’ structure has a better resistance to erosion compared to a more columnar ‘Normal’ structure, which leads to less degradation of the TBC. However, under the influence of CMAS infiltration the effect was found to be reversed. In general, CMAS-infiltrated EB-PVD TBCs exhibit a higher erosion resistance than the non-infiltrated ones.     

Deposition of silver ions onto DBD and DCSBD plasma treated nonwoven polypropylene

The aim of this work is plasma activation of nonwoven polypropylene (PP) using two different ambient air plasma sources: volume dielectric barrier discharge (DBD) and diffuse coplanar surface barrier discharge (DCSBD) and its functionalization by silver ion deposition.     

Crystalline Intermediate Phases in the Sol–Gel-Based Synthesis of La2NiO4+δ

X-ray diffraction and transmission electron microscopy were applied to investigate a sol–gel synthetic process for the mixed oxygen ion and electron conductor La₂NiO_4+δ with a K₂NiF₄ structure type. The development of the La₂NiO_4+δ is elucidated considering the influence of calcination temperatures and dwell times. Following the thermal decomposition of nitrate and organic precursors in an intermediate step, the lanthanum nickel oxide is obtained after a short dwell time above 750°C. This occurs by the transformation of an ultrafinely dispersed powder consisting of lanthanum oxycarbonate, lanthanum oxide, and nickel oxide. The pure La₂NiO_4+δ phase was obtained by similar solid-state reactions between nanocrystalline powder particles at just 950°C.