1,720,966 research outputs found
Improvement of Biochar Through Ozonization and Biosafety of Genetically Engineered Cyanobacteria
Get PDFThrough the innovative technique of biochar post-production surface oxygenation by ozonization, we were able to improve certain properties of biochar. In project one, the incubation of an insoluble phosphate rock material (hydroxyapatite) with the wet ozonized pine 400 biochar and its filtrate resulted in a solubilization of 80 times more phosphate from hydroxyapatite (569.0 mg/L ± 6.4) compared to the pure water-hydroxyapatite control (7.2 mg/L ± 0.3). The ozonized biochar may provide a new possible way to unlock the phosphorus from insoluble phosphate mineral phases. The cation exchange capacity (CEC) is a key property of biochar when used as a soil amendment. In project two, using a high surface area biochar (rogue biochar), we were able to increase the CEC by a factor of almost 10 times upon ozone treatment; a biochar with an initial CEC of 17.02 cmol/kg ± 0.63 was increased to 152.08 cmol/kg ± 4.06 upon ozonization. The process of biochar ozonization generated large amount of dissolved organic carbon (DOC) in the filtrate/wash. Previously discarded as waste, here we showed that these DOC, even at low concentrations, may be useful for some applications such as unlocking phosphate from phosphate rock material. In project four, the bioassay of ozonized biochar substances was conducted on soil bacteria Pseudomonas putida and freshwater cyanobacteria Synechococcus elongatus PCC 7942. Results indicated that ozone treatment of certain biochars reduced their inhibiting effect on some microorganisms. The biocontainment of genetically engineered (GE) cyanobacteria was recognized as a concern in case the latter was to break containment and escape into the environment. In project five, we tested the thermophilic nature of Thermosynechococcus elongatus BP1 as a biocontainment. A growth study in the greenhouse of Old Dominion University with genetically engineered (GE) Thermosynechococcus elongatus BP1-BY20 with biofuels producing genes showed that the GE T. elongatus BP1-BY20 did not actively grow in cool (15.44 oC to 25.30 oC) or warm season (31.42 oC to 36.27 oC) in the greenhouse. The thermophilic nature of T. elongatus BP1 may serve as a biosafety guarded mechanism during cool seasons but not so much during warmer seasons
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Investigation Into the Effect of Ozonation on Biochar as a Function of Pyrolysis Temperature and Its Applications in Dye Removal
No full textThe need to sequester carbon from the global carbon cycle has never been greater; global warming continues unchecked as the world population is predicted to reach 10 billion by 2100. Converting waste biomass generated by agriculture and forestation activities into biochar for soil amendment not only removes carbon from the carbon cycle, but it also locks it in a highly stable form. Beyond biochar’s ability to retain soil water/nutrients and reduce fertilizer runoff when introduced into soils, research has indicated that cropland fertility can also be improved by biochars with high cation exchange capacity (CEC). Ozonation of biochar adds the carboxylic functional groups on biochar surfaces necessary for increased biochar CEC without requiring the use of hazardous reagents. To assess the ozonization methods which yield the greatest improvement to biochar adsorption capacity, a number of biochar sample materials were exposed to cationic and anionic aqueous solutions during a 10-day dye exposure experiment. Three treatments (non-ozonized control, dry-ozonized and wet-ozonized) of four biochar varieties made at different temperatures (P300, P400, P500 and RBC) were exposed to two different dyes, methylene blue (MB) and Congo red (CR). UV-Vis spectroscopy was utilized to determine the unbound dye molecules remaining in solution as a function of time. It was determined that all biochar samples tested had a greater capacity for the cationic dye, MB, than the anionic CR dye, with the RBC and P300 series close to 100% dye removal in solution by the end of 10 days exposure. These results suggest that ozonization not only leads to an increase in CEC but may also affect the biochar’s anion exchange capacity (AEC), an important property that needs more investigation
Variations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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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