1,720,958 research outputs found
Kinetic of the Sewage Treatment: The Consumption of Organic Carbon of The Microalga Chlorella sp
Full text linkAs well known, microalgae are eukaryotic or procaryotic microorganisms able to photosynthesize, namely
transforming inorganic substrates and sun light into organic compounds and chemical energy. They result very
promising in treating civil wastewaters thanks to their ability to employ nitrates and phosphates as nutrients
(Lima et al., 2019). Autotrophic microalgae are, anyway, not useful in decreasing the organic carbon content of
wastewaters, and for this reason, they cooperate with heterotrophic bacteria. The usefulness of microalgaebacteria consortia in treating wastewaters and the ratio of their inoculum was investigated in a previous work
(Lima, 2022a). Contrarily to autotrophic microalgae, mixotrophic microalgae are able to decrease the organic
content of the matrix in which they are grown. In this work, we preliminarily investigated the capability of the
autochthonous microalga Chlorella sp. CW2 to grow in mixotrophy and decrease the organic content of the
artificial wastewater in which they are grown. Several batch cultivations were performed with glucose in different
concentrations. Kinetic parameters were obtained and employed to determine the dilution rate (D) ideal for the
abatement of glucose from the artificial wastewater
MODELLING OF THE GROWTH OF NANNOCHLOROPSIS GADITANA IN DIFFERENT REACTOR GEOMETRIES, EXPERIMENTAL KINETIC PARAMETERS FROM BATCH CULTURES AND BIOCHEMICAL ANALYSIS OF THE OBTAINED BIOMASS
No full textMicroalgae are unicellular and photosynthetic microorganisms that grow using inorganic salts, CO2 and light, and are applied in numerous industrial sectors due to their variety and properties. Due to the lack of information on how microalgae respond to external inputs and to the different environments in which they grow, today the industrial application is not exploited as it should.
It is therefore necessary to create models that allow to predict microalgal growth in different photobioreactors to improve our knowledge, still poorly investigated.
In this work the Monod equation for the specific growth rate was combined with the Lambert-Beer law for the non-homogeneous light distribution in a flat photobioreactor.
Model kinetic parameters related to the cultivation of the microalga Nannochloropsis gaditana were obtained from batch cultivations under different photon-flux densities inside a quasi isoactinic photobioreactor. These parameters were applied in a mathematical model, based on the geometric system considered, for obtaining microalgae growth curves.
Biochemical analyses on the obtained biomass were also executed at the end of each batch cultivation to assess how light distribution influences biomass composition.
The obtained model allowed to successfully predict the growth of the microalga Nannochloropsis gaditana in the different photobioreactor geometries
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
Experimental and Computational Study of Supercritical Fluid Extraction (SFE) of Omega-3 Components from Fish Oil in Structured Packing
Full text linkThe benefits of polyunsaturated fatty acids and their implications for human health have gained scientific
attention to their extraction from biological sources, not being produced by the human body. Most known
industrial productions of omega-3 fatty acids often work under operating conditions that may degrade these
components and they often use toxic or flammable solvents that can adversely affect human health. In this
sense, innovative and interesting prospects are provided by Supercritical Fluid Extraction (SFE).
In this work, two parallel studies were carried out: an experimental activity in a laboratory apparatus using
supercritical carbon dioxide (scCO2) and preliminary computational fluid dynamics (CFD) simulations, limited to
the hydrodynamic aspects of the process. In the experimental apparatus a Sulzer® EX structured packing, made
up of corrugated metal gauze sheets, was used as the column filler. The study made it possible to identify the
optimal operating conditions leading to an enrichment of the starting mixture in Eicosapentaenoic acid (EPA)
and Docosahexaenoic acid (DHA), target products. CFD simulations were based on the Volume of Fluid (VOF)
approach, suitable to the present complex multiphase system with two phases in close contact (transesterified
fish oil and scCO2). The meatus created by the corrugations of the metal gauze was chosen as the calculation
domain representative of the system. The computations were performed by the commercial software Ansys
Fluent®, which allowed the prediction of the hydrodynamic evolution of the system through transient simulations.
CFD predictions were in qualitative agreement with the experimental result
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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