1,720,962 research outputs found
Production de biogaz et de compost à partir de eichhornia crassipes, (mart) solms-laub (pontederiaceae) pour un développement durable en Afrique sahélienne
No full textIn the urban park BANGR-WEOOGO of the commune of Ouagadougou (Burkina Faso) the proliferation of the water hyacinth threatens the conservation of the biodiversity. The application of the integrated fight, did not permit the éradication. The aim of the study, is to contribute to the installation of a protocol of management of Eichornia crassipes which associates the mechanical fight with valorization by the production of biogas and compost. The results show a significant production of biomass with a proportion of dry weight (DW) of 6,12 %. The experiment, carry out with some discontinuous digesters of 200 liters using 60 kg of water hyacinth as substrate mixed with 20 liters of liquid manure bacterium méthanogènes, indicate a average of bio gas production of 1440 liters for 3,67 kg of dry matter of water hyacinth witch means 392,37 liters /kg/ DW. The composts resulting from these experiments contain average 9,930 kg de total phosphore, 0,690 kg of ortho-phosphate, 6,27 kg nitrogene d’azote (N-Kjeldahl) 1,1 kg of organic carbon per ton of compost. The application of this technology in the wetlands infested by E crassipes has several advantages: energy production, compost and control of the proliferation of the water hyacinth.
Production de biogaz et de compost à partir de eichhornia crassipes, (mart) solms-laub (pontederiaceae) pour un développement durable en Afrique sahélienne
No full textDans le parc urbain Bangré-Weoogo de la commune de Ouagadougou (Burkina Faso) la prolifération de la jacinthe d’eau menace la conservation de la biodiversité. L’application de la lutte intégrée n’a pas permis de l’éradiquer. L’objectif de l’étude est de contribuer à la mise en place d’un protocole de gestion de Eichornia crassipes qui associe à la lutte mécanique la valorisation par la production de biogaz et de compost. Les résultats montrent une importante production de biomasse avec une proportion de matière sèche de 6,12 %. Les expérimentations, menées avec des digesteurs de type discontinu de 200 litres de capacité avec pour substrat 60 kg de la jacinthe d’eau ensemencée avec 20 litres de purin de bactéries méthanogènes indique une production moyenne de biogaz de 1440 litres de bio gaz pour 3,67 kg de matière sèche de jacinthe, soit 392,37 litres /kg/ MS. L’analyse chimique a montré que le compost issu de ces expérimentations contient, entre autre 9,930 kg de phosphore total, et 0,690 kg d’ortho-phosphate, 6,27 kg d’azote Kjeldahl par tonne de compost. L’application de cette technologique dans les zones humides infestées par E. crassipes présente plusieurs avantages : production d’énergie, de compost et contrôle de la prolifération de la jacinthe d’eau.In the urban park BANGR-WEOOGO of the commune of Ouagadougou (Burkina Faso) the proliferation of the water hyacinth threatens the conservation of the biodiversity. The application of the integrated fight, did not permit the éradication. The aim of the study, is to contribute to the installation of a protocol of management of Eichornia crassipes which associates the mechanical fight with valorization by the production of biogas and compost. The results show a significant production of biomass with a proportion of dry weight (DW) of 6,12 %. The experiment, carry out with some discontinuous digesters of 200 liters using 60 kg of water hyacinth as substrate mixed with 20 liters of liquid manure bacterium méthanogènes, indicate a average of bio gas production of 1440 liters for 3,67 kg of dry matter of water hyacinth witch means 392,37 liters /kg/ DW. The composts resulting from these experiments contain average 9,930 kg de total phosphore, 0,690 kg of ortho-phosphate, 6,27 kg nitrogene d’azote (N-Kjeldahl) 1,1 kg of organic carbon per ton of compost. The application of this technology in the wetlands infested by E crassipes has several advantages: energy production, compost and control of the proliferation of the water hyacinth.
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
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
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