1,720,955 research outputs found
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
Isolation of trigonelline from natural materials and its antioxidant activity
Get PDFGrško seno je rastlina, bogata je z mnogimi hranljivimi snovmi in se lahko uporablja v različnih oblikah, zato je koristen dodatek k zdravi prehrani. Pripomore k izboljšanja zdravja in dobrega počutja ljudi. Ena izmed koristnih bioaktivnih spojin v grškem senu je trigonelin. Raziskave in vitro so potrdile antioksidativne in protivnetne lastnosti.
V magistrski nalogi smo optimizirali ekstrakcijo trigonelina iz grškega sena. Izvedli smo kvantitativno in kvalitativno analizo ekstraktov in materiala. Določili smo korelacijo med temperaturo in stabilnostjo trigonelina in preverili obstojnost spojine v človeških prebavilih. Analizirali smo tudi antioksidativne lastnosti pridobljenih ekstraktov.
Ugotovili smo, da je za grško seno najbolj ustrezna Soxhletova ekstrakcija z metanolom, ugodne pa so tudi vodne raztopine etanola. Potrdili smo, da trigonelin ni antioksidant, vendar ekstrakti izražajo antioksidativno aktivnost zaradi prisotnosti fenolnih spojin. Pri testiranju termične stabilnosti trigonelina smo potrdili termolabilnost ciljne spojine. Rezultati gastrointestinalnega testa so pokazali, da je trigonelin obstojen tudi v stiku s prebavnimi encimi.Fenugreek is a plant rich in nutrients and can be used in many different forms, making it a useful addition to a healthy diet. It has been shown to improve human health and well-being, furthermore, in vitro studies have confirmed antioxidant and anti-inflammatory properties of fenugreek. One of the beneficial bioactive compounds in fenugreek is trigonelline.
In this thesis, the extraction of trigonelline from fenugreek has been optimized. Quantitative and qualitative analysis of the extracts and material has been performed. The correlation between temperature and stability of trigonelline has been determined, and the rate of decay in the human gastrointestinal tract has been assessed. The antioxidant properties of the obtained extracts have also been analysed.
The results have indicated that Soxhlet extraction with methanol has been the most suitable method for trigonelline extraction from fenugreek, while aqueous ethanol solutions have also appeared to be appropriate solvents. It has been confirmed that trigonelline is not an antioxidant, however, the obtained extracts have shown antioxidant activity due to the presence of phenolic compounds. In the thermal stability testing of trigonelline, the thermolabile nature of the target compound has been confirmed. The results of the gastrointestinal test have shown that trigonelline is stable even in contact with digestive enzymes
Smart coatings for corrosion protection of the construction materials
Get PDFKorozija povzroča degradacijo kovinskih materialov, ki so v stiku s tekočino ali plinom. Sam proces se pospeši z izpostavitvijo visokim temperaturam, kislinam in solem. Posledično se spremenijo lastnosti materiala in nastaja škoda pri samem tehnološkem procesu. Da bi korozijo upočasnili, uporabljamo različna inhibitorna sredstva, ki so lahko organske ali anorganske narave.
Diplomsko delo prikazuje študijo pametnih prevlek kot zaščito pred korozijskimi procesi na kovinski površini. Prevleka vsebuje inkapsuliran inhibitor, ki se sprosti, ko se nahaja v agresivnem okolju. Njegovo delovanje lahko zapolni poškodbe na prevleki, ki nastanejo ob fizični poškodbi, ob spremembi pH na medfazni površini med prevleko in korozivnim medijem ter podobnim. Ovojnica kapsule se ob tem predre, sprošča se inhibitor, ki se običajno adsorbira na površino in na tak način nudi dodatno zaščito pred korozijo.
Uporabili smo vzorce iz aluminijeve zlitine tipa EN AW 6451 in jih predhodno obdelali tako, da je bila oprijemljivost prevleke iz epoksidne smole z inkapsuliranimi delci inhibitorja čim večja. Zaščitni sloj smo nanesli z metodo \u27spin coatinga\u27, ki ustvari enakomerno tanek sloj zaščitne prevleke na površini preiskovanega vzorca. Testirane prevleke so vsebovale tri različne koncentracije inkapsuliranih delcev inhibitorja. Največjo inhibicijsko učinkovitost je imela \u27pametna prevleka\u27 z najvišjim utežnim odstotkom inkapsuliranih delcev, ki so vsebovali kationski surfaktant. Za korozivni medij smo uporabili vodno raztopino natrijevega klorida z dvema različnima koncentracijama (3,5 % in 0,1 mol/L). Meritve smo izvedli na vzorcih po 30-minutni stabilizaciji v raztopini na mirovnem potencialu in po 48 urni predhodni izpostavitvi korozivnemu okolju. V posameznih primerih smo dosegli tudi najvišjo možno vrednost inhibicijske učinkovitosti in sicer = 99 % - 100 % .Corrosion presents a process that causes degradation of metal, when it comes into contact with liquid or gases. The process accelerates with exposure to high temperature, acidic solvents and salts. Chemical deterioration of a material leads to technological problems. Therefore, various inhibitors (organic or inorganic) are used for corrosion protection.
This thesis presents the study of smart coatings for corrosion protection of metal materials. The coating contains an encapsulated inhibitor, which is released in contact with the agressive medium. Its activation can fill the gaps on the surface coating. The flaws in the coating can be caused by many factors, e.g. a physical injury, changed pH at the contact of the metal with the corrosive environment. Nanocapsules are able to detect active corrosion and release the inhibitor that increases corrosion protection.
Aluminium based metalic substrates (EN AW 6451) were used in the experiments, which were previously processed for better adhesion of epoxy coating with nanocapsules containing the corrosion inhibitor. Spin coating was employed to apply the smart coating onto the metal surface. Tested coatings were prepared using three different concentrations of encapsulated cationic surfactant. The best inhibition efficiency was exhibited by the smart coating with the highest mass fraction of nanocapsules within the mixture. A water solution of sodium chloride with two different concentrations (3,5 % and 0,1 mlol/L) was used as corrosive medium. Tests were performed after 30 minute stabilisation of the sample in the solution and after 48 hour exposure to the corrosive environment. The applied smart coatings show a high potential fort he use as an efficient corrosion protection
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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