1,720,963 research outputs found
Engineering a Dual-Functionalized PolyHIPE Resin for Photobiocatalytic Flow Chemistry.
Get PDFThe use of a dual resin for photobiocatalysis, encompassing both a photocatalyst and an immobilized enzyme, brings several challenges including effective immobilization, maintaining photocatalyst and enzyme activity and ensuring sufficient light penetration. However, the benefits such as integrated processes, reusability, easier product separation, and potential for scalability can outweigh these challenges, making dual resin systems promising for efficient and sustainable photobiocatalytic applications. In this work we employ a photosensitizer-containing porous emulsion-templated polymer as a functional support that is used to covalently anchor a chloroperoxidase from Curvularia inaequalis (CiVCPO). We demonstrate the versatility of this heterogeneous photobiocatalytic material which enables the bromination of four aromatic substrates, including Rutin - a natural occurring flavonol - under blue light (456 nm) irradiation and continuous flow conditions
Photoactive materials enabled by and for emerging synthetic technologies
Get PDFIn recent years there has been a significant increase in the development and
commercialisation of new synthetic tools and technologies, which offer significant
advantages compared to traditional round-bottomed flask chemistry. This work explores
the use of some of these emerging technologies with the goal of developing new
photocatalytic processes, which would not otherwise be easily feasible with batch
techniques. Specifically, we have used continuous flow chemistry, mechanochemistry,
and 3D printing in four distinct research projects. This thesis is split into five chapters in
total.
Chapter 1 aims to act as a global introduction to the different synthetic technologies that
were used and compare their utility and drawbacks against traditional batch synthetic
methodologies. The remaining chapters 2-5 each represent a separate research project
that utilises these new technologies. Each chapter contains its own introduction to the
topic of research along with conclusions and proposed future work.
Specifically, in Chapter 2, a rapid, high yielding, and work-up free synthesis of an
unusual organic luminophore is developed. Its twisted, propeller-like geometry gives rise
to much sought aggregation induced emission properties. Moreover, we were able to use
this material as a reusable heterogeneous photosensitiser to produce singlet oxygen under
continuous flow conditions.
In Chapter 3, we report the unprecedented ring contraction of 1,2,6-thiadiazines to 1,2,5-
thiadiazole 1-oxides. The transformation is fast, work-up free, offers quantitative yields,
and is mediated by auto-photosensitised singlet oxygen. We exploited continuous flow
processes to further improve the reaction scope and efficiency.
Then, in Chapter 4 we describe the batch and mechanochemical syntheses of optically
active dihydroxamic acids ligands, and their subsequent use for the synthesis of metalloorganic assemblies.
Finally, Chapter 5 demonstrates how mechanochemical and 3D printing technologies
were used to access a series of N-aryl amides from O-protected hydroxamic acids.
The broad scope of this work aims to demonstrate the usefulness of alternative reactor
designs in chemical synthesis and encourage their implementation by others
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
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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