Search results for "Acte"

Linear friction welding of dissimilar AA6082 and AA2011 aluminum alloys: microstructural characterization and design guidelines

2015

This paper presents the results of an experimental and numerical campaign on Linear Friction Welding of dissimilar AA2011-T8 and AA6082-T6 aluminum alloys. Experimental tests were carried out with constant oscillation amplitude and process time. Varying oscillation frequency, interface pressure, specimen geometry and mutual position were used. Grain size measurements, HV tests and EDX analysis were considered to characterize the microstructure of the joints as a function of the input process parameters. A thermal numerical model was utilized to predict the temperature profiles in the joints during the process. The obtained results allowed the identification of four weld categories: sound jo…

Microstructural, mechanical and energy demand characterization of alternative WAAM techniques for Al-alloy parts production

2020

Abstract Additive manufacturing (AM) processes are gathering momentum as an alternative to conventional manufacturing processes. A research effort is being made worldwide to identify the most promising AM approaches. Within this category, wire arc additive manufacturing (WAAM) is among the most interesting, especially when large parts must be manufactured. In this paper, two different WAAM deposition techniques suitable for the deposition of Aluminum alloys, Cold Metal Transfer (CMT) and CMT mix drive, are analyzed and compared. With the aim of obtaining a clear picture concerning the two different techniques, microstructural analyses, mechanical property evaluation and electrical energy de…

Beyond cells – The virome in the human holobiont

2019

Viromics, or viral metagenomics, is a relatively new and burgeoning field of research that studies the complete collection of viruses forming part of the microbiota in any given niche. It has strong foundations rooted in over a century of discoveries in the field of virology and recent advances in molecular biology and sequencing technologies. Historically, most studies have deconstructed the concept of viruses into a simplified perception of viral agents as mere pathogens, which demerits the scope of large-scale viromic analyses. Viruses are, in fact, much more than regular parasites. They are by far the most dynamic and abundant entity and the greatest killers on the planet, as well as th…

Fusta de les serres ibériques (1750-1790) : L'impacte de la demanda per a la construcció fluvial a Cartagena

2014

Performance and feasibility of biotrickling filtration in the control of styrene industrial air emissions

2017

Abstract The performance and feasibility of a pilot unit of biotrickling filter (BTF) for the treatment of industrial emissions polluted by styrene was investigated for one year at a fiber reinforced plastic industrial site. The pilot unit was packed with a structured material with a volume of 0.6 m3. Monitoring results have shown successful treatment of the industrial styrene emissions working at empty bed residence times (EBRT) between 31 and 66 s. The best performance was obtained after 300 days when a more stable biofilm had been developed, obtaining the highest elimination capacity of 18.8 g m−3 h−1 (removal efficiency of 75.6%) working at 31 s of EBRT. In addition, a photocatalytic re…

Transformation of Construction Cement to a Self-Healing Hybrid Binder

2019

A new biomimetic strategy to im prove the self-healing properties of Portland cement is presented that is based on the application of the biogenic inorganic polymer polyphosphate (polyP), which is used as a cement admixture. The data show that synthetic linear polyp, with an average chain length of 40, as well as natural long-chain polyP isolated from soil bacteria, has the ability to support self-healing of this construction material. Furthermore, polyP, used as a water-soluble Na-salt, is subject to Na+/Ca2+ exchange by the Ca2+ from the cement, resulting in the formation of a water-rich coacervate when added to the cement surface, especially to the surface of bacteria-containing cement/c…

A numerical model for pre-monitoring design of historical colonnade courtyards: The case study of chiaramonte palace in palermo

2016

This paper proposes a numerical model that can be used for theoretical and experimental dynamic characterization of historical colonnade courtyards. Such an architectural element appears often in buildings of historical heritage and, especially under seismic excitation, it represents the most vulnerable structural part. Therefore, it is very important to have reliable as well as simple models available for vulnerability analysis, to evaluate different reinforcing systems if needed, or to plan dynamic characterization tests or monitoring campaigns, as in the present case. Chiaramonte Palace, a wonderful example of the historical heritage of Palermo, is investigated as case study. Firstly, a …

Comparison of fully non-stationary artificial accelerogram generation methods in reproducing seismicity at a given site

2020

Abstract Seismic input modelling is a crucial step when Non-Linear Time-History Analyses (NLTHAs) are performed, the seismic response of structures being highly responsive to the input employed. When natural accelerograms able to represent local seismicity are not available, the use of generated accelerograms is an efficient solution for input modelling. The aim of the present paper is to compare four methods for generating fully non-stationary artificial accelerograms on the basis of a target spectrum, identified using seven recorded accelerograms registered in the neighbourhood of the construction site during a single event, assumed as target accelerograms. For each method, seven accelero…

Development of a fast characterization setup for radionuclide generators demonstrated by a 227Ac-based generator

2021

Abstract The development of a setup for a fast online characterization of radionuclide generators is reported. A generator utilizing the mother nuclide 227Ac sorbed on a cation exchange resin is continuously eluted by using a peristaltic pump. To allow continuous and pulse-free elution of a large volume over extended time periods a 3D-printed interface designed to remove pressure-oscillations induced by the pump was placed between pump and generator column to ensure undisturbed generator elution. The eluate of the generator is passed through a 3D printed flow cell placed inside a borehole Na(Tl)-scintillation detector for high counting efficiency. Alternatively, a HPGe detector suitable for…

Incidence de l’endophtalmie aiguë postopératoire après chirurgie de la cataracte par phacoémulsification et injection intracamérulaire d’antibiotique…

2016

National audience; Introduction La chirurgie de la cataracte est l’intervention la plus fréquente dans le monde. Parmi ses complications, l’endophtalmie aiguë postopératoire (EAPO) est une infection intraoculaire sévère, qui peut conduire à la cécité. Les objectifs étaient de déterminer l’incidence de l’EAPO après chirurgie de la cataracte par phacoémulsification en France de 2005 à 2014 et d’analyser l’association entre injection intracamérulaire d’antibiotique (IICA) et EAPO. Méthodes Tous les patients hospitalisés pour une chirurgie de la cataracte en France entre le 1er janvier 2005 et le 31 décembre 2014 ont été identifiés dans le programme de médicalisation des systèmes d’information …