Effect of welding sequence in angular distortion on butt joint GMAW process

Over time, the industrial use of the welding process has grown in significance and is now one of the primary methods for joining metallic parts. During the welding process, metallurgical and structural modifications occur close to the welded joint. The thermal stresses and geometric distortions are undesirable, and they are a challenge to accurately forecast. Laboratory tests were conducted utilizing the GMAW method on S235JR steel as the base material with the goal of examining the impact of the welding sequence on angular distortion in butt joints when comparing three different welding sequences. Equipment that can determine coordinates in the operational space with metrological accuracy was used to measure distortions. As a result of metrological and statistical analyses, it was found that the sequence factor is shown to substantially influence the final distortions and that the symmetrical method results in less distortions followed by a one-step method.Financial support was provided by Portugal’s national funding FCT/MCTES (PIDDAC) to Centro de Investigação de Montanha (CIMO) (UIDB/00690/2020 and UIDP/00690/2020) and SusTEC (LA/P/0007/2020).info:eu-repo/semantics/publishedVersio

Analysis of a vegetable oil performance in a milling process by MQL lubrication

In this work, we carried out a comparison between the dry machining of an aluminum block with conventional cutting oil and a block with vegetable oil. The two oils had different flow rates. Using the Taguchi method, it was possible to determine the matrices for optimizing the best parameters for each group of tests. Then, we studied the utility of using vegetable oil as a cutting lubricant. We found that the vegetable oil studied in this work had good properties in terms of reducing cutting temperatures but was less effective than conventional cutting oil in reducing the surface roughness of the machined part. Tribological tests were carried out to understand the influence of the selected lubricants in reducing friction and wear. After the sliding experiments, which were performed without lubrication in the presence of the same lubricants that were used in the machining tests and in the presence of distilled water, we concluded that vegetable oil has satisfactory lubricating properties that are similar to those of the conventional cutting fluid, indicating a potential for consideration as an effective alternative to the conventional cutting fluid, with economic, environmental, and health advantages.Financial support was provided by Portugal’s national funding FCT/MCTES (PIDDAC) to Centro de Investigação de Montanha (CIMO) (UIDB/00690/2020 and UIDP/00690/2020) and SusTEC (LA/P/0007/2020). Additionally, this work was partially supported by Portuguese FCT, under the reference projects UIDB/04077/2020, UIDB/00532/2020 and UIDB/04436/2020. This research was also partially funded by EXPL2021CIMO_01. Inês Afonso acknowledges the financial support of CIMO through EXPL2021CIMO_01.info:eu-repo/semantics/publishedVersio

Diving into the vertical dimension of elasmobranch movement ecology

Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements