Intermetallic titanium aluminide alloys are used in the high technology engineering field with the goal of achieving weight reduction in different components, exposed to corrosive environments and high temperatures in aeronautical and automotive industries. Despite their attractive properties such as low density, high strength, high stiffness and good corrosion, creep and oxidation resistance, the machinability of titanium aluminide alloys is difficult due to its high hardness, chemical reactivity, and low ductility. This article reviews the state of the art regarding the machinability of titanium aluminide alloys and focuses on the analysis of the milling process, namely the process parameters, surface integrity and cutting tools. The influence of titanium aluminides properties on the machinability is also discussed presenting some current trends and further needed research.

Plastics are a common residue of our activities and, when incorrectly disposed, high quantities of this type of products end up in the environment, namely through landfilling and dumping into the aquatic compartments. Therefore, water streams and basins are contaminated threatening wildlife, which ultimately can entail human toxicity by means of the food-chain effect. One of the major concerns relies on microplastics which, due to its size and nature, constitute a more difficult to handle residue.
This paper presents an endeavour to control, reduce or even mitigate the presence of plastic debris in the environment, with the benefit of converting them into energy or other valuable commodities for the actual society. Gasification can be seen as one of the most effective techniques for this purpose, featuring a more environmental friendly scheme for treating this kind of residues, avoiding their overspread throughout Nature, as well as complying with environmental policies.

consider to be a synonymous of additive manufacturing has made its way into the medical field, not only manufacturing medical appliances, study models or building prosthetics. The demand for bone substitution surgeries is growing every year, due to the increase in pathologies affecting bone structure (both traumatic and not traumatic). Nowadays with the possibility of three-dimensional printers becoming bioprinters, engineered bone tissue is starting to become a reality. The aim of this paper is to give the reader an overview of the work done in the last few years towards the advance of three-dimensional printing methods for engineered bone tissue. This paper is divided into six parts, an introduction, then presentation and discussion of the various printing methods with special focus on additive manufacturing (AM), then of bioprinting technologies, further directions of these technologies are considered and a conclusion is done.

This paper describes a study on applying data mining techniques to power transformer failure prediction. The data set used consisted not only on DGA tests, but also in other tests done to the transformer’s insulating oil. This dataset presented several challenges, such as highly imbalanced classes (common in failure prediction problems), and the temporal nature of the observations.
To overcome these challenges, several techniques were applied for prediction and better understand the dataset. Pre-processing and temporality incorporation in the dataset is discussed. For prediction, a 1-class and 2-class SVM, decision trees and random forests, as well as a LSTM neural network were applied to the dataset.
As the prediction performance was low (high false-positive rate), we conducted a test to ascertain if the amount of data collected was sufficient. Results indicate that the frequency of data collection was not adequate, hinting that the degradation period was shorter than the periodicity of data collection.

Adhesives are increasingly being used in the aerospace and automotive industries. They allow for light weight vehicles, fuel savings and reduced emissions. However, the environmental degradation of adhesive joints is a major setback in its wider implementation. Moisture degradation of adhesive joints includes plasticization, attacking of the interface, swelling of the adhesive and consequent creation of residual stresses. The main factors affecting the strength of adhesive joints under high and low temperatures are the degradation of the adhesive mechanical properties and the creation of residual stresses.
To model the long term mechanical behaviour of adhesive joints, the temperature and moisture dependent properties of the adhesives must be known. However, few studies focus on the combined moisture and temperature degradation, which difficults the prediction of the long term mechanical behaviour of these joints. In this study the prediction of moisture and temperature dependent cohesive properties of a structural adhesive is analysed.

Alkaline activation of fly ashes is a procedure that enables an alternative binder which has been receiving much interest by several research groups particularly on the manufacturing of mortars and concretes. The properties of the materials that are developed during the alkaline activation are influenced by the curing conditions (temperature and relative humidity). Another relevant facet related to the curing procedures is the possibility of carbonation occur, which may have an impact on the mechanical strength of the alkaline cements. In this research, several sets of curing conditions were tested to understand which one results in a higher strength and reveals carbonation. Uniaxial compressive strength tests were conducted to assess mechanical behavior. The outcome suggests that higher temperature and low relative humidity yields higher mechanical strength.