1,720,991 research outputs found
Formulation and Evaluation of Controlled-Release Diuron as Pre-Emergence Herbicide
Get PDFControlled-release formulations of diuron were prepared in the laboratory using
the concept of physical matrix utilizing sodium alginate and kaolin. The release rates of
diuron from the formulations were determined by chemical assay and bioassay. In the
chemical assay, using high performance chromatography with UV detector, significant
differences in release rates between formulations were observed from 3 to 7 days after
the granules were placed into distilled water. The formulation having a 1:1 ratio of
alginate to kaolin with 1 mm granule size showed the fastest release of diuron while
release from the 2 mm granules was slower. The release of diuron from the
formulations reached a maximum level of 27% at 30 days after placement in water this
same rate of release was maintained up to 60 days after the treatment. Increasing the
proportion of kaolin to sodium alginate in the controlled-release formulation reduced the
release rate of active agent.
Bioassays were conducted in the glasshouse to study the release rates of diuron
using Brassica rapa seedlings as bioindicator. The controlled-release formulations
showed slower release than the conventional formulation at the beginning of the
treatments. At 3 weeks after treatment, there was no significant difference in the
mortality of the seedlings between the conventional formulation and controlled-release
formulations. However, the controlled-release formulations gave significantly higher
seedling mortality compared to the conventional formulation at 16 weeks after the
treatments. The same results were observed up to 24 weeks after the treatment when
the controlled-release formulations caused between 40 to 70% mortality, while the
conventional formulation treatment caused only 6% mortality. Among the controlledrelease
formulations, the A K-2 formulation (1:1, alginate to kaolin) was found to give the
best control with the highest percentage mortality of the seedlings
Silvery tunnel
Get PDFHuman has been living together with millions of insects species for as long as the world exists. Thus the relationship of human and insect was formed in many ways. One of the forms is the work arts. Insect provide inspirations and creativity to humans. One of these creative insects is the citrus leaf miner (Phyllocnistis citrella Stainton)
Pesticides and food safety for Malaysian fresh vegetables
No full textEThOS - Electronic Theses Online ServiceGBUnited Kingdo
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
- …
