1,720,961 research outputs found
Functionalization of Frustules of the Diatom Staurosirella pinnata for Nickel (Ni) Adsorption From Contaminated Aqueous Solutions
Full text linkThe structural characteristics of diatom cell walls (frustules) has led to their widespread use in diverse biotechnological applications, some of which can be further improved by surface chemical modification (functionalization). The use of coating agents can significantly increase surface binding capacity for target compounds. Frustules of the diatom Staurosirella pinnata used here were a by-product after applying a cascade-extraction process (for other products) to mass cultures. The protocol for the cleaning and functionalization of raw frustules using 3-Mercaptopropyl-trimethoxysilane and 3-Aminopropyl-trimethoxysilane was optimized and reported. Functionalization efficacy was observed using Electron Microscopy, Energy Dispersive X-ray Spectroscopy and Fourier-Transform Infrared Spectroscopy. Optimally functionalized frustules were evaluated for nickel removal from aqueous solutions. Incubations of 10 min, using 1 g/L of frustules, gave almost complete Ni removal with functionalized frustules compared to 3% removal by raw frustules. The proposed protocol represents a reproducible and efficient alternative for Ni removal from contaminated water
The biological filter for an innovative Sustainable Product System to recycle domestic wastewater
No full textThe reuse and saving of water in the domestic cycle is pivotal to achieve the sustainability of cities. An important step in the recycling of wastewaters (WWs) is the use of multispecific microbial consortia able to degrade and mineralize the organic matter present in the WWs; they can be used either attached or suspended, acting as biofilters.
In this framework, the reduction and upcycling of WWs represents the main goal of the innovative Sustainable Product System (SPS) made of a dishwasher integrated with an indoor planting device, under development in a multidisciplinary co-design team. This SPS includes, among other components, a biological filter, engineered with different microbial strains, some of them collected among the dishwasher wastewater colonizers.
In this study we selected and co-cultivated filamentous, biofilm forming, cyanobacteria (Trichormus spp.), isolated from dystrophic environments, together with some of the common heterotrophic bacteria present in the dishwashing WWs as Acinetobacter, Exiguobacterium and Pseudomonas spp.. Different combinations were tested in a set of culture systems and conditions (light, temperature, flow velocity and WW dilutions) to evaluate the efficiency in cleaning WWs, stripping of gross particulate, degrading of organic load, with ultimate nutrient mineralization used to support the growth of edible plants included in the integrated device. Simultaneous metagenomic analysis and community-based culture collection of the dishwasher wastewater allow (i) to directly explore the entire pool of microbial genomes and (ii) to identify and cultivate the bacterial populations ensuring the most efficient mineralization of dishwasher WWs. This strategy will lead to the assemblage of a self-sustaining, highly effective and customized microbial consortium/filter. This filter will be beneficial to both the environment and the economic circular domains, by reducing water use and wastewater discharge but simultaneously permitting the up-cycling of domestic WWs in on site food production
Functionalization of Frustules of the Diatom Staurosirella pinnata for Nickel (Ni) Adsorption From Contaminated Aqueous Solutions
No full textThe structural characteristics of diatom cell walls (frustules) has led to their widespread use in diverse biotechnological applications, some of which can be further improved by surface chemical modification (functionalization). The use of coating agents can significantly increase surface binding capacity for target compounds. Frustules of the diatom Staurosirella pinnata used here were a by-product after applying a cascade-extraction process (for other products) to mass cultures. The protocol for the cleaning and functionalization of raw frustules using 3-Mercaptopropyl-trimethoxysilane and 3-Aminopropyl-trimethoxysilane was optimized and reported. Functionalization efficacy was observed using Electron Microscopy, Energy Dispersive X-ray Spectroscopy and Fourier-Transform Infrared Spectroscopy. Optimally functionalized frustules were evaluated for nickel removal from aqueous solutions. Incubations of 10 min, using 1 g/L of frustules, gave almost complete Ni removal with functionalized frustules compared to 3% removal by raw frustules. The proposed protocol represents a reproducible and efficient alternative for Ni removal from contaminated water
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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