1,720,954 research outputs found
DEGRADATION OF MEPANIPYRIM BY PHOTOCATALYTIC OZONATION
No full textThe occurrence of not easily degradable pesticides in the hydrosphere, due to intensive agricultural activities, is of particular concern for surface and groundwater quality. In this respect, it is advisable to strengthen existing technologies for the decontamination of water, with the aim of enhance the degradation methods for recalcitrant organic compounds. [1]
In our previous study, we have demonstrated that the application of advanced oxidation processes promises to be a profitable expedient for the rapid degradation and detoxification of persistent herbicides as imazethapyr. [2]
The capabilities of the oxidation processes to degrade organic pollutants in water and the variety of derivatives formed is illustrated here by the case of Mepanipyrim [N-(4-methyl-6-prop-1-ynylpyrimidin-2-yl)aniline], a widely used pyrimidinic fungicide. The purpose of this study was to simulate the production of degradation compounds, which can be arisen in water treatment plants where physical or chemical oxidation methods are normally used. Comparisons between different oxidation techniques can provide useful information on the mechanisms of these processes, and are of particular concern in the assessment of the most efficient experimental conditions for the destruction of organic pollutants. The advanced oxidation methods compared were ozonation (without application of any initiator), UV-photolysis and UV-O3 coupled treatment. Kinetics of reactions were determined. Numerous degradation products were identified and characterised through MS spectra analyses.
Toxicity tests on Microtox, Daphnia magna and Lactuca sativa were carried out on the mix of degradation products
DEGRADAZIONE OSSIDATIVA DEL MEPANIPYRIM, UNA ANILINO-PIRIMIDINA
No full textL’utilizzo degli agrofarmaci è ancora oggi il mezzo più semplice ed efficace per il controllo delle avversità delle piante. Rimane, pertanto, di estrema attualità considerare che i composti organici ad uso fito-farmacologico, una volta raggiunto il loro bersaglio (suolo, acqua, vegetali), sono soggetti a tutta una serie di possibili e complessi fenomeni di trasformazione biotica ed abiotica. La sostanza bio-attiva inalterata e/o i suoi prodotti di trasformazione e degradazione possono essere diffusi nell'ecosistema diventando spesso un pericolo per l'ambiente e per gli organismi non-bersaglio.
Uno dei processi abiotici più studiati è la degradazione che avviene ad opera delle radiazioni luminose. La fotodegrazione ed altri processi degradativi (chimici e biochimici) costituiscono le uniche vere vie di rimozione di un agrofarmaco dall’ambiente, in quanto tutti gli altri processi, che non comportano trasformazione della molecola madre, determinano solo uno spostamento dello xenobiotico da un comparto ambientale ad un altro.
Negli ultimi anni è stato mostrato un crescente interesse verso l’utilizzo dell’ozonolisi come possibile mezzo alternativo nell’eliminazione dei residui dei agrofarmaci. L’ozono (O3), infatti, è un gas altamente reattivo le cui eccellenti proprietà ossidative nei confronti di sostanze organiche ed inorganiche vengono ampiamente utilizzate anche nel trattamento di purificazione dell'acqua per uso potabile.
Per verificare le potenzialità dei processi di fotolisi ed ozonolisi nella depurazione di acque contaminate, in questo lavoro è stato studiata la degradazione in presenza di luce ed ozono del Mepanipyrim (fig.1), un fungicida appartenente alla famiglia delle anilino-pirimidine attivo contro la Muffa grigia (Botrytis cinerea) su vite, fragola e pomodoro. Con lo scopo di valutarne la cinetica di reazione e di identificarne i prodotti di degradazione in fase liquida, il Mepanipyrim è stato sottoposto a diversi trattamenti degradativi durante i quali ne è stata seguita la variazione di concentrazione in funzione del tempo di esposizione. I risultati ottenuti hanno messo in evidenza come l’ozonizzazione sia un processo più efficace nella degradazione del Mepanipirym rispetto alla fotolisi
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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