1,721,217 research outputs found
Retrieval of marine water constituents using atmospherically corrected AVIRIS hyperspectral data
No full textLinear stability of a liquid flow through a poroelastic channel
No full textA liquid flow through a channel is studied based on the Orr-Sommerfeld eigenvalue problem, where the lower wall of the channel is occupied by the saturated poroelastic medium. The linear stability analysis is investigated in detail for arbitrary value of the wavenumber. The eigenvalues are computed numerically by using the Chebyshev spectral collocation method. The effect of physical parameters, for instance, permeability, elasticity as well as their combined effect on the unstable modes are examined
Unveiling Adsorption of Boron Dipyrromethene Conjugated PbS Nanocrystals on Pt Electrode Surface: An Approach Using Electrogenerated Chemiluminescence Spooling Spectra and Multivariate Analysis
No full textThis research focuses on the adsorption and molecular scale communication mechanism of PbS-BDY (BDY, boron dipyrromethene), a nanohybrid system of nanocrystal (NC) and a ?-conjugated molecule, investigated through the electrogenerated chemiluminescence (ECL) spooling spectra and multivariate analysis. The results show that the charge transmitted from the excited state of BDY + to the surface states of PbS NCs leads to emission quenching of BDY and emission enhancement of PbS NCs at 986 nm. Also, the essence tendency of unpassivated sulfur atoms on (100) facets of the PbS NCs acts as a force for adsorption of PbS NCs on the surface of Pt electrode. This phenomenon was proved by conjugation of BDY as an ECL active compound to the PbS NCs and multivariate analysis of augmented data at different scan rates. The obtained results from multivariate analysis reveal that adsorption of PbS-BDY and charge transfer from BDY to surface states of PbS NCs are independent of the scan rate
Sustainable materials from fish industry waste for electrochemical energy systems
No full textFish industry waste is attracting growing interest for the production of environmentally friendly materials for several different applications, due to the potential for reduced environmental impact and increased socioeconomic benefits. Recently, the application of fish industry waste for the synthesis of value-added materials and energy storage systems represents a feasible route to strengthen the overall sustainability of energy storage product lines. This review focused on an in-depth outlook on the advances in fish byproduct-derived materials for energy storage devices, including lithium-ion batteries (LIBs), sodium-ion (NIBs) batteries, lithium-sulfur batteries (LSBs), supercapacitors and protein batteries. For each of these, the latest applications were presented together with approaches to improve the electrochemical performance of the obtained materials. By analyzing the recent literature on this topic, this review aimed to contribute to further advances in the sustainability of energy storage devices
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
Role of Copper in the Onset of Alzheimer's Disease Compared to Other Metals
No full textAlzheimer's disease (AD) is a neurodegenerative disorder that is characterized by amyloid plaques in patients' brain tissue. The plaques are mainly made of beta-amyloid peptides and trace elements including Zn2+, Cu2+, and Fe2+. Some studies have shown that AD can be considered a type of metal dyshomeostasis. Among metal ions involved in plaques, numerous studies have focused on copper ions, which seem to be one of the main cationic elements in plaque formation. The involvement of copper in AD is controversial, as some studies show a copper deficiency in AD, and consequently a need to enhance copper levels, while other data point to copper overload and therefore a need to reduce copper levels. In this paper, the role of copper ions in AD and some contradictory reports are reviewed and 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
Precipitation hardening stainless steel samples processed by additive manufacturing: Process parameters and thermo mechanical treatments effects on microstructure and corrosion resistance
No full textThe effects of different process parameters and thermo mechanical treatments on 17–4 PH samples processed by Selective Laser Melting have been investigated in this study. Overlap, scanning radius and laser beam defocusing were varied while all the other process parameters were kept constant. So, the role of process parameters was analysed in terms of microstructure, defectiveness and response to heat treatment. Specifically, the as built samples were subjected to stress relaxation heat treatment (650 ◦C-2 h) and H 900 heat treatment (solution treatment at 1100 ◦C 1 h + 480 ◦C-1 h). On the as built, stress relieved and H 900 heat treated samples the corrosion resistance, microstructural evolution and hardness were studied. Moreover, Ultrasonic Peening treatment (UPT) was applied and its effect corrosion resistance was evaluated. The study was carried out by optical, scanning and transmission electron microscopes, Vickers hardness, DRX and Image analysis software. It was found that the amount of austenitic phase increases with the decreasing of the scanning radius from 5000 μm to 1250 μm; with positive defocusing of laser beam (+1mm) respect to in focus processed sample and with increasing of the overlap from 25 μm to 50 μm. Each samples exhibit pores lower than 0,3% in terms of area percentage and mostly circular in morphology. In the process variability window, no significant difference in defects occurrence were observed. In the as built state, different values of hardness were found according to the different microstructure and average grain size. After the stress relaxation heat treatments at 650 ◦C-2 h all the samples exhibit similar hardness values while the most austenitic and finer grained as built samples exhibit higher increasing in hardness after H900 heat treat ment. Corrosion resistance changes as function of the different process parameter and heat treatment and is improved by Ultrasonic Peening mechanical treatment
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