The effect of minimum quantity lubrication in the intermittent turning of magnesium based on vibration signals

The present work shows an experimental investigation on intermittent turning based on vibration signals. The dependence of vibrations on the feed rate, minimum quantity lubrication (MQL) flow rate and the type of the interruption of the workpiece is evaluated. The results indicate that a part of the vibrations depends on the flow rate of the MQL system and its interaction with the feed rate, finding no dependency on the type of interruption. The influence of the MQL system is greater when machining at the lower feed rate. In addition, a strong relation between surface roughness and vibrations is identified. However, this relation is quite different depending on the environment used. In general, under dry conditions, the higher the vibrations the higher the surface roughness, while the opposite occurs when the MQL system is used.publishe

Relationship Between Biogenic Amines and Free Amino Acid Contents of Winesand Musts from Alentejo (Portugal)

The concentration of biogenic amines and free amino acids was studied in 102 Portuguese wines and 18 musts from Alentejo demarcated (D.O.C.) regions. Most wines were commercial, except for 38 monovarietals obtained by micro vinification. Musts from the varieties used to produce the latter wines were also studied. Both biogenic amines and free amino acids were analyzed by HPLC using fluorescence detection for their o-phthalaldehyde/fluorenylmethyl chloroformate (OPA/FMOC) derivatives. The most significant amines (average 10.8 mg/L for histamine+tyramine in red, and 7.4 mg/L for white wines) were found to be present at low levels and, although no important relationship between each individual biogenic amine could be obtained, the total amine content depends significantly on the assimilable amino acid content in wine

Creación de un Laboratorio de Análisis Socio-Político de América Latina (AMELAT -LAB)

El objetivo principal de este proyecto era crear un espacio de colaboración entre estudiantes, investigadores y profesores para el análisis y comprensión de problemáticas y fenómenos sociales y politicos actuales en América Latina

Behaviour of a biocompatible titanium alloy during orthogonal micro-cutting employing green machining techniques

The sustainability of a process is the objective of modern industries aiming to reduce waste in production, since consumers require high quality and efficiency with fair price. Thus, a good understanding of the process should be its starting point. The manufacture of dental implants is an example in which waste reduction is important for the reduction of prices due to the demand for great quality and accuracy. This study observed the behaviour of sustainable micro-cutting applied to the Ti-6Al-7Nb titanium alloy, considering the ploughing effect on minimum quantity lubrication (MQL) and high-speed machining (HSM) conditions. When compared with dry condition and low-speed cutting in orthogonal micro-cutting, the use of HSM in dry cutting was more efficient than using MQL. The dry condition presented lower surface roughness, whilst the cooled/lubricated condition presented lower burr formation.publishe

Enhancing productivity by means of high feed rate in the drilling of Al 2011 aluminium alloy

Drilling is one of the most popular machining operations in industry. It is employed for manufacturing a large number of materials (e.g. steel, aluminium, and composite) and in various sectors (e.g. aeronautic, automotive, and medical). Nowadays, increasing productivity and reducing costs, without compromising the quality of the products, are two main objectives for most manufacturing companies. In machining, the increase in the feed rate can cause the reduction in the cutting time and, thus, increase productivity. Based on that, the present work analyses the use of high feed rates in the drilling of Al 2011 aluminium alloy. For that purpose, the diameter and surface roughness obtained with the tool feed rate recommended by the manufacturer (conventional feed) and high feed, in both dry and wet conditions, were compared. In general, the use of high feed improves surface roughness, mainly in wet condition. When comparing the optimal condition for both conventional and high feed processes, the diameter of the hole did not present significant variation. However, the surface roughness was lower with the high feed, between 26.7 and 81.6%, diminishing the cutting time by 84.3%The authors would like to thank the University of the Aveiro and Sandvik (Portugal). Additional thanks to the Ministry of Education’s Coordination for the Improvement of Higher Education Personnel (CAPES)—Brazil (Grant No. 0330-12-4) and Foundation for Science and Technology (FCT), Portugal (Project No. 031556-FCT/02/SAICT/2017; FAMASI—Sustainable and intelligent manufacturing by machining, financed by FCT/POCI).in publicatio

Actividad práctica de diseño para la fabricación asistida con CATIA: Doblado de chapa metálica

Congreso Universitario de Innovación Educativa En las Enseñanzas Técnicas, CUIEET (26º. 2018. Gijón