Conformal polishing approach: Tool footprint analysis

Polishing process is one of the most critical manufacturing processes during a metal part production because it determines the final quality of the product. Free-form surface polishing is a handmade process with lots of rejected parts, scrap generation and time and energy consumption. Two different research lines are being developed: prediction models of the final surface quality parameters and an analysis of the amount of material removed depending on the polishing parameters to predict the tool footprint during the polishing task. This research lays the foundations for a future automatic conformal polishing system. It is based on rotational and translational tool with dry abrasive in the front mounted at the end of a robot. A tool to part concept is used, useful for large or heavy workpieces. Results are applied on different curved parts typically used in tooling industry, aeronautics or automotive. A mathematical model has been developed to predict the amount of material removed in function of polishing parameters. Model has been fitted for different abrasives and raw materials. Results have shown deviations under 20% that implies a reliable and controllable process. Smaller amount of material can be removed in controlled areas of a three-dimensional workpiece

Effect of the feed presentation form on the intake pattern, productive traits and rumen pH of beef cattle fed high concentrate diets

Nutritional disorders like ruminal acidosis are common in Spanish beef production system, in which animals are fed diets with a high content in starch. This experiment studied the effect of feed presentation form (concentrate and straw offered separately, CD, or mixed in form of briquettes, BR) on the pattern of intake, growth and rumen pH of beef cattle fed high concentrate diets. The experiment was performed with 40 Holstein male calves, 32 of them for determining feed intake pattern and productive rates, and the remaining 8, which were previously provided with a ruminal cannula, to monitor rumen pH in two 21-day consecutive periods following a change-over design. Animals fed BR reduced feed intake rate during the first hour after feeding (18.6 vs. 24.0% of daily intake p<0.001), but this diet promoted a lower rumen pH at all sampling times compared with CD (daily average of 5.98 vs. 6.33; p<0.001) and tended to promote a lower total feed intake (7.08 vs. 9.77 kg DM d–1; p<0.001) and daily weight gain (1.43 vs. 1.76 kg d–1; p=0.056). Offering the concentrate and the straw mixed in form of briquettes is not useful to prevent ruminal acidosis and improve growth, probably due to both a reduced particle size of straw and avoided self-regulation of straw intake along the day. Additional key words: fee

TXNDC5, a newly discovered disulfide isomerase with a key role in cell physiology and pathology

Thioredoxin domain-containing 5 (TXNDC5) is a member of the protein disulfide isomerase family, acting as a chaperone of endoplasmic reticulum under not fully characterized conditions As a result, TXNDC5 interacts with many cell proteins, contributing to their proper folding and correct formation of disulfide bonds through its thioredoxin domains. Moreover, it can also work as an electron transfer reaction, recovering the functional isoform of other protein disulfide isomerases, replacing reduced glutathione in its role. Finally, it also acts as a cellular adapter, interacting with the N-terminal domain of adiponectin receptor. As can be inferred from all these functions, TXNDC5 plays an important role in cell physiology; therefore, dysregulation of its expression is associated with oxidative stress, cell ageing and a large range of pathologies such as arthritis, cancer, diabetes, neurodegenerative diseases, vitiligo and virus infections. Its implication in all these important diseases has made TXNDC5 a susceptible biomarker or even a potential pharmacological target

Mechanical and microstructural features of wire-and-arc additively manufactured carbon steel thick plates

Metal additive manufacturing (AM), in particular wire-and-arc additive manufacturing (WAAM), has become over the last few years the breakthrough technology to reduce the environmental impact and increase the efficiency of steel structures. Although intense research effort has been paid toward the mechanical characterization of WAAM-produced thin walls, little attention has been devoted to the investigation of multi-layered thick parts. These latter would indeed expand the application of WAAM for large-scale constructions requiring thicker cross-sections to withstand high loading conditions. The present work provides a comprehensive experimental investigation of mild steel WAAM thick plates from the fabrication to the mechanical and microstructural characterization. First, the fabrication process is presented in full details. From that, microstructural and mechanical characterization is described and discussed, showing a homogeneous microstructure with little influence on the mechanical response along the wall plate thickness, also considering different specimen orientations with respect to the printing directions. The results confirm good mechanical properties of the printed outcomes, in line with those of structural mild steels manufactured with conventional technologies. Little influence on the response along the thickness is reported, thus proving the required quality of WAAM thick parts for applications in the construction sector

Evaluating the impact of lean practices on environmental performance: evidences from five manufacturing companies

Previous evidence suggests that both lean and green production paradigms are focused on waste reduction and that lean practices help organizations to enhance sustainability objectives, and particularly environmental performance. However, the impact of lean practices on the environment is still unclear. This study therefore aims to analyse the relationship between lean and environmental performance in manufacturing with a strong empirical focus. This research was conducted in two main stages: first, an extensive review of the relevant literature was carried out, followed by a multiple case study analysis conducted in five manufacturing companies. Onsite data were collected from the firms during a five years’ time span of research and developing semi-structured interviews. Furthermore, a cross-case analysis was carried out to map the results. Findings indicate that the environmental performance of the companies analysed is generally enhanced in the long-term after the implementation of lean. Moreover, the results from the multiple case study suggest that the environmental performance of the firms under analysis is mainly improved by using JIT and TQM practices in a lean transformation context. The research findings provide further results remarking the possible negative impact of practices such as Kanban deliveries, 5S and TPM on various environmental performance indicators.N/

Dynamic Structure and Subsurface Oxygen Formation of a Working Copper Catalyst under Methanol Steam Reforming Conditions: An in Situ Time-Resolved Spectroscopic Study

"This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Catalysis, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acscatal.8b05042."[EN] The dynamic behavior of a CuO/ZnO/Ga2O3 catalyst under methanol steam reforming (MSR) reaction conditions promoted by a high dispersion of the copper nanoparticles and defect sites of a nonstoichiometric ZnGa2O4 spinel phase has been observed, where structural changes taking place in the initial state of the reaction determine the final state of the catalyst in stationary reaction conditions. Mass spectrometry (MS) studies under transient conditions coupled to X-ray photoelectron spectroscopy (XPS) have shown copper oxidation to Cu+ in the initial state of the reaction (TOS = 4 min), followed by a fast reduction of the outer shell to Cu-0, while keeping dissolved oxygen species in the inner layers of the nanoparticle. The presence of this subsurface oxygen impairs a positive charge to the uppermost surface copper species, that is, Cu delta+, which undoubtedly plays an important role on the MSR catalytic activity. The detection of these features, unperceived by conventional spectroscopic and catalytic studies, has only been possible by combining synchrotron NAP-XPS studies with transient studies performed in a low volume catalytic reactor connected to MS and linked with Raman and laboratory scale XPS studies.The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP/2007-2013) for the Fuel Cells and Hydrogen Joint Technology Initiative under Grant Agreement No. [303476]. Part of this work was financially supported by the following projects: (i) Project POCI-01-0145-FEDER-006939 (Laboratory for Process Engineering, Environment, Biotechnology and Energy UID/EQU/00511/2013) funded by the European Regional Development Fund (ERDF), through COMPETE2020 - Programa Operacional Competitividade e Internacionalizacao (POCI) and by national funds, through FCT - Fundacao para a Ciencia e a Tecnologia; (ii) NORTE-01-0145-FEDER-000005 - LEPABE-2-ECO-INNOVATION, supported by North Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF); and (iii) the Spanish Government-MINECO through "Severo Ochoa" Excellence Programme (SEV-2016-0683). D.R. thanks European Research Council project SYNCATMATCH (671093). J.C. thanks the Spanish Government (MINECO) for a "Severo Ochoa" grant (BES-2015-075748). The NAP-XPS experiments were performed at the NAPP branch of the CIRCE beamline at the ALBA Synchrotron with the collaboration of ALBA staff.Ruano-Sánchez, D.; Cored-Bandrés, J.; Azenha, C.; Pérez-Dieste, V.; Mendes, A.; Mateos-Pedrero, C.; Concepción Heydorn, P. (2019). Dynamic Structure and Subsurface Oxygen Formation of a Working Copper Catalyst under Methanol Steam Reforming Conditions: An in Situ Time-Resolved Spectroscopic Study. ACS Catalysis. 9(4):2922-2930. https://doi.org/10.1021/acscatal.8b05042S292229309

Synthesis and characterization of nanocrystalline U1−x_{1-x}Pux_{x}O2(+y)_{2(+y)} mixed oxides

We report here the first synthesis of mixed oxide U$_{1-x}$Pu$_{x}$O$_{2(+y)}$ nanoparticles. The obtained nanopowders were characterized by X-ray diffraction, thermal ionization mass spectrometry, transmission electron microscopy, Raman spectroscopy, and U M$_{4}$ edge high-energy-resolution X-ray absorption near edge structure (HR-XANES). The HR-XANES spectra give evidence for the partial oxidation of U$^{IV}$ to U$^{V}$. This novel route toward the formation of actinide–actinide solid solution opens research opportunities that are not accessible using bulk materials. We give details on the X-ray diffraction study on plutonium oxalate hexahydrate, as a reagent for the synthesis of such nanoparticles

S12-3 School-based physical activity promotion in a cross-cultural context: interventions from France and Spain

Abstract citation ID: ckad133.060 S12-3 School-based physical activity promotion in a cross-cultural context: interventions from France and Spai