1,720,971 research outputs found
Plasma nano-texturing of polymers for wettability control: Why, what and how
No full textNano-texturing of polymers offers the possibility to drive important surface properties such as wettability and anti-reflectivity. Interestingly, plasma can lead to the desired characteristic of nanofeatures through a one step process based onto dry plasma etching. In this work, the literature concerning such plasma nano-texturing will be reviewed for different polymers, and in particular, for applications based upon wettability control. Then the mechanism of such processes will be commented upon, with a glance to the different characteristics of the polymers. Finally, some hints onto a feasible approach to plasma nano-texturing of the different polymers will be given
Plasma-assisted deposition of fungicide containing coatings for encapsulation and protection of maize seeds
No full textThe aim of the research work here reported is to illustrate how to incorporate prothioconazole, a molecule with fungicide action, in plasma-deposited polymeric coating, encapsulating maize seeds. With this approach, high fungicide effect with a small quantity of chemicals and less pollution of soil and water should be achieved. The fungicide composite coating is composed of three layers: a hydrophilic plasma deposited polymeric layer to increase the wettability of the seed surface; a layer of sprayed prothioconazole aqueous solution; and a hydrophobic plasma deposited barrier layer to limit leaching and mimic the natural seed wettability. The application of the composite coating is found not to interfere with the germination of the seeds, while the percentage of maize crowns infected by Fusarium graminearum was successfully reduced from 94% in the control to none in the coated seeds
Cold plasma pretreatment improves the germination of wild asparagus (Asparagus acutifolius L.) seeds
No full textThe cultivation of wild asparagus does not require many input because it adapts very easily to adverse pedoclimatic conditions. The main limit to its cultivation is the long time necessary for germination and the low germinability of seeds. In this study, the effect of cold plasma pretreatment on wild asparagus seed germination was evaluated. Seed plasma pretreatments (mixtures of O2/N2 applied for different times) were compared with conventional ones, namely: soaking (water), priming (polyethylene glycol), and hormonal (gibberellic acid). The effects of seed stratification and temperature on germination were also investigated. The stratification reduced the time required for germination of about 180 d. Plasma treatment, gas feed with 20–80% O2/N2 for 1 min, resulted more effective in increasing the germination percentage (by 15%) and reduced of 5 d the time to reach half of maximum germination percentage (T50). This performance is related to both the increase in water uptake and the fungal disinfectant properties of plasma treatment. This study confirms that the application of cheap and eco-friendly cold plasma technology could provide improvements in the cultivation of wild asparagus
TiO2-based nanomaterials assisted photocatalytic treatment for virus inactivation: perspectives and applications
No full textThe COVID 19 pandemic has demonstrated the need for urgent access to measures to contain the spread of the virus and bacteria. In this frame, the use of photocatalytic nanomaterials can be a valuable alternative to chemical disinfectants without the limitation of generating polluting by-products and with the advantage of re-usability in time. Here, on the basis of up-to-date literature reports, the use of TiO2-based photocatalytic nanomaterials in disinfection will be overviewed, considering the peculiar nanocatalysts assisted inactivation mechanisms. The potential of this class of photocatalysts for air, surface and water disinfection will be highlighted, critically revising the recent achievements in view of their potential in real application
Aerosol assisted atmopheric pressure PE-CVD of drug containing nano-capsules
No full textIn this review an overview is given on bio-composite coatings, on their applications and the plasma-based processes for their deposition. In particular, we describe the innovative possibility to deposit, via aerosol-assisted atmospheric pressure plasma, drug containing nano-capsules in a one-step process. The application of these peculiar bio-composite materials as cyto-compatible bactericidal drug release coatings have been examined, with different molecules embedded in the same polyethylene-like plasma-deposited matrix: Vancomycin, gentamicin and lysozyme. In conclusion, a hypothesis on the formation mechanisms of the nano-capsules is proposed, which could be very interesting for numerous potential applications
Recent advancements in the use of aerosol-assisted atmospheric pressure plasma deposition
Full text linkAtmospheric pressure plasma allows for the easy modification of materials' surfaces for a wide range of technological applications. Coupling the aerosol injection of precursors with atmospheric pressure plasma largely extends the versatility of this kind of process; in fact solid and, in general, scarcely volatile precursors can be delivered to the plasma, extending the variety of chemical pathways to surface modification. This review provides an overview of the state of the art of aerosol-assisted atmospheric pressure plasma deposition. Advantages (many), and drawbacks (few) will be illustrated, as well as hints as to the correct coupling of the atomization source with the plasma to obtain specific coatings. In particular, the deposition of different organic, hybrid inorganic-organic and bioactive nanocomposite coatings will be discussed. Finally, it will be shown that, in particular cases, unique core-shell nanocapsules can be obtained
One-step plasma texturing of polytetrafluoroethylene: surfaces with unique morphology and dynamic water repellent behavior
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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