1,722,217 research outputs found
THE MANUAL AND THE CLAY. NOTES ON WHERE TO GO FROM THERE
No full textIl volume costituisce l'esito della Cooperazione Internazionale Han_Pisa, finanziata con fondi europei e istituita con l'obbiettivo di attivare uno scambio di contributi scientifici legati alla conservazione del patrimonio archeologico e in particolare del legno bagnato . Il contributo dell'autore riguarda la valutazione dello stato attuale dell'esperienza maturata dallo Han Yang Ling Museum in chiave museografica e le prospettive future. Allo scritto è anche associata una proposta progettuale sviluppata in occasione di un workshop tenutosi presso lo Han Yang Ling Museum di Xian dal 21 al 28 novembre 2008, e presentata in una sezione iniziale del volume (fuori dall'articolo)
Design and characterization of nanocrystalline graphite/graphene based environmental sensors
No full textCarbon based thin films, such as graphene and graphite are promising materials for environmental sensing due to their chemical and mechanical stability, low-toxicity and selectivity towards certain environmental parameters. The scope of environmental sensing for this project will be limited to sensing of humidity and oxidizing gases for environmental monitoring applications. The most widely used methods to fabricate carbon based thin films rely on either physical transfer of CVD grown graphene films, or the deposition of graphene flakes onto substrates. However, such methods are less compatible with standard semiconductor manufacturing processes. The variations caused by the film transfer (wrinkling, defects, different flake sizes etc) could cause variance in sensing performance which is not ideal. Therefore, we proposed the use of nanocrystalline graphite/graphene (NCG) films deposited with plasma-enhanced CVD (PECVD) onto large area substrate as a potential solution. The PECVD deposited NCG has high grain boundary concentrations, which makes it ideal for sensing applications as the sensing effect is thought to lie in the grain boundaries. At the boundaries, charge transport barrier is formed between two or more conductive nanocrystals. Interactions between elements in the environment may alter the charge transport barrier significantly, thus, causing a measurable change in the conductivity of the film.The PECVD method for NCG deposition was studied with NCG deposited at different substrate temperature to obtain the Arrhenius deposition rate. Electrical characterization and surface characterization were done on each sample to study the effect of deposition temperature on the fabrication of the film. The deposition rate between wafer scale deposition and sample scale deposition was studied, and it was found that on sample scale deposition, the deposition rate is slower than the wafer scale process due to the temperature difference introduced by a carrier wafer in the sample scale production process. The uniformity of the deposition was investigated using ellipsometry. AFM and FESEM images of the deposited films shown that the films consists of graphitic grains which are about 20-40 nm.Here, the sensing behaviour of PECVD NCG towards different gas type is reported for the first time. The sensitivity of NCG towards 3 different gases, NO2, NH3, and CO was shown. The resistance of a strip (30 μm by 3000 μm, with thickness of 34 nm) decreases by 0.663% upon exposure to 10 ppm of NO2, increases by 0.14% upon exposure to CO and increases by 0.1% upon exposure to NH3. The desorption rate for the gas is observed to be slow. The characteristics of resistance change matches that of a p-type semiconducting gas sensor. Using Hall effect measurements, the majority carrier was found to be holes instead of electrons.The humidity sensing performance of PECVD NCG was also demonstrated for the first time in this thesis. Upon exposure to humid air (95% relative humidity), the resistance of the sensor drops 3% (Sensor dimensions 10 μm by 20 mm meandered strip, with thickness of 200 nm). The effect of different geometrical designs on the sensing performance of the NCG humidity sensor was also investigated.A potential application of this device is to incorporate such a sensor in a smart breath monitoring mask which monitors the wearer’s respiration patterns continuously for applications such as health monitoring during physical activities or rest. Tests were carried out to investigate the effects of bodily fluids such as human perspiration and saliva on the reliability of the sensor. The sensor shows great recovery and virtually no degradation to its sensing performance after exposure to KCl solutions
34 VB Yang Ling Quan dans les dystocies de démarrage
No full textAcupuncture obstétricaleLes situations de pré-travail qui dure sans mise en travail, ou de dystocie de démarrage, sont choses courantes dans notre pratique quotidienne. Comment la puncture du 34VB, le point maître des muscles et des tendons, peut-elle aider la parturiente en favorisant la dynamique de l’accouchement ? Notamment parce que le 34VB, point mer de Zu Shao Yang, traite son entraille la Vésicule Biliaire qui a l’initiative de la vie et qui régit tous les commencements. L’effet de Yang Ling Quan, 34VB, serait ainsi tout aussi important sur le mental que sur le corpore
Prospecção de flavonóides em espécies do gênero cyathea
Full text linkTCC (graduação) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Curso de Química.O presente trabalho de prospecção de flavonóides em Cyatheae, mostra o isolamento e a identificação de flavonóide glicosilado, e um ácido cafêico também glicosilado. O gênero Cyatheae, família Cyatheacea, faz parte da classe das Pteridófitas que são plantas conhecidas popularmente por samambaias, avencas e xaxim. As Pteridófitas são consideradas plantas anciãs, pois no processo evolutivo da terra foram as primeiras espécies a habitarem terra firme e as que existem hoje, são aquelas que sobreviveram à seleção natural, sem contudo sofrerem evolução. Por isso mesmo, estas plantas apresentam uma grande importância do ponto de vista arqueológico. O isolamento e a identificação de compostos glicosilados foram por via de técnicas simples de cromatografia em coluna de sílica, técnica espectroscópicas de IV, RMN 1H, RMN l3C, RMN bidimensional entre outras técnicas laboratoriais
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
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