Search results for "PASS"
showing 10 items of 1629 documents
A Gramsci Renaissance?
2022
In this article, some recent pedagogical studies about Gramsci’s philosophy of praxis will be analyzed. Starting from these studies, the author ar-gues for the possibility of reading the contemporaneity through Gram-scian lens. In particular, he puts forward the hypothesis of using category of passive revolution to decipher the neoliberal reforms of the (Italian) school system.
New behavioural trait adopted or rejected by observing heterospecific tutor fitness
2010
Animals can acquire behaviours from others, including heterospecifics, but should be discriminating in when and whom to copy. Successful individuals should be preferred as tutors, while adopting traits of poorly performing individuals should be actively avoided. Thus far it is unknown if such adaptive strategies are involved when individuals copy other species. Furthermore, rejection of traits based on tutor characteristics (negative bias) has not been shown in any non-human animal. Here we test whether a choice between two new, neutral behavioural alternatives—breeding-sites with alternative geometric symbols—is affected by observing the choice and fitness of a heterospecific tutor. A fiel…
Critical Review—Photocurrent Spectroscopy in Corrosion and Passivity Studies: A Critical Assessment of the Use of Band Gap Value to Estimate the Oxid…
2017
A critical assessment of the Photocurrent Spectroscopy (PCS) Technique for the semi-quantitative characterization of passive film and corrosion layers composition is carried out. We take into account more than three decades of PCS usage as "in-situ" analytical technique and related results as well as the criticism of the underlying semi-empirical correlation relating the measured optical bandgap (Eg) to the passive film composition. The discrepancies between the experimental data, gathered by PCS measurements, and Egestimates originating from recently developed Density Functional Theory based modeling of solid state properties are stressed with particular emphasis on the case of anodic pass…
Broadband tuning of a long-cavity all-fiber mode locked Thulium-doped fiber laser using an acousto-optic bandpass filter
2019
A long-cavity passively mode-locked thulium-doped all-fiber laser is reported incorporating a tapered acousto-optic tunable bandpass filter (AOTBF). The operation of the AOTBF relies on the intermodal coupling between core and cladding modes when a flexural acoustic wave propagates along an 80-microm tapered fiber. The filter works in transmission and exhibits a 3-dB bandwidth of 9.02 nm with an insertion loss of 3.4 dB. The laser supports ultrashort pulse generation at a low repetition rate of 784.93 kHz. Optical pulses with 2.43 nm of optical bandwidth and 2.1 ps pulse duration were obtained in a broad tuning range from 1824.77 to 1905.16 nm.
Recent advances on physico-chemical characterization of passive films by EIS and differential admittance techniques
2007
Abstract Thin Nb2O5 anodic films (∼20 nm thick) grown in phosphoric acid solution have been characterised by EIS and differential admittance study in a large range of potential and frequency. The overall electrical behaviour has been interpreted by means of the theory of amorphous semiconductor Schottky barrier in presence of a non-constant density of states (DOS). A comparison of DOS for films grown in different electrolytes is reported.
Effect of NaClO disinfection/cleaning on passive films on AISI 316L
2020
Abstract 316 L stainless steel samples were passivated in NaClO containing solutions in order to simulate disinfection processes. Passive films were grown at the open circuit potential by immersion in NaClO aqueous solutions at different concentrations and temperature in order to understand how exposure to aggressive environments could affect subsequent corrosion resistance of SSs. In the attempt to study the passive film growth mechanism, in-situ Open Circuit Potential measurements were performed in the same growth solutions. Photoelectrochemical and impedance investigation of passive films was carried out in order to link their solid state properties with their corrosion behaviour.
Photoelectrochemical monitoring of rouging and de-rouging on AISI 316L
2017
Electrochemical conditions for inducing rouging on surface of AISI 316L in quasi neutral aqueous solution are studied. Potentiostatic polarization at 0.6 V vs. SSC at pH ∼ 7 allowed growth of colourless passive films with a band gap slightly lower than that estimated for the oxide grown on the SS surface by air exposure due to chromium dissolution. Under stronger anodic polarization (UE = 1.5 V vs. SSC) coloured passive films are formed, mainly constituted by iron oxide according to their band gap (Eg = 2.0 eV). Etching in citric acid at 60 °C results to be effective in removing rouging.
Photocurrent spectroscopy in passivity studies
2018
The aim of this article is to present photocurrent spectroscopy as useful in situ technique for the physicochemical characterization of passive films and corrosion layers. The response of (both amorphous and crystalline) semiconductor/electrolyte junction under irradiation is treated and discussed in order to get information about solid-state properties such as band gap and flat band potential. The possibility to use Photocurrent Spectroscopy (PCS), in a quantitative way, to get information on the composition of corrosion layers is discussed through a semiempirical correlation between the band gap of the oxides (or hydroxides) and the difference of electronegativity of their constituents. F…
ePTFE ‐based biomedical devices: An overview of surgical efficiency
2021
International audience; Polytetrafluoroethylene (PTFE) is a ubiquitous material used for implants and medical devices in general because of its high biocompatibility and inertness: blood vessel, heart, table jawbone, nose, eyes, or abdominal wall can benefit from its properties in case of disease or injury. Its expanded version, ePTFE is an improved version of PTFE with better mechanical properties, which extends its medical applications. A material as frequently used as ePTFE with these exceptional properties deserves a review of its main uses, developments, and possibility of improvements. In this systematic review, we examined clinical trials related to ePTFE-based medical devices from t…
Effect of alloying elements on the electronic properties of thin passive films formed on carbon steel, ferritic and austenitic stainless steels in a …
2014
The influence of alloying elements on the electrochemical and semiconducting properties of thin passive films formed on several steels (carbon steel, ferritic and austenitic stainless steels) has been studied in a highly concentrated lithium bromide (LiBr) solution at 25 °C, by means of potentiodynamic tests and Mott Schottky analysis. The addition of Cr to carbon steel promoted the formation of a p-type semiconducting region in the passive film. A high Ni contentmodified the electronic behaviour of highly alloyed austenitic stainless steels.Mo did notmodify the electronic structure of the passive films, but reduced the concentration of defects.