Surface tension effects on submerged electrosprays     

álvaro G. Marín  Ignacio G. Loscertales  Antonio Barrero 《Biomicrofluidics》2012,6(4)

Electrosprays are a powerful technique to generate charged micro/nanodroplets. In the last century, the technique has been extensively studied, developed, and recognized with a shared Nobel price in Chemistry in 2002 for its wide spread application in mass spectrometry. However, nowadays techniques based on microfluidic devices are competing to be the next generation in atomization techniques. Therefore, an interesting development would be to integrate the electrospray technique into a microfluidic liquid-liquid device. Several works in the literature have attempted to build a microfluidic electrospray with disputable results. The main problem for its integration is the lack of knowledge of the working parameters of the liquid-liquid electrospray. The “submerged electrosprays” share similar properties as their counterparts in air. However, in the microfluidic generation of micro/nanodroplets, the liquid-liquid interfaces are normally stabilized with surface active agents, which might have critical effects on the electrospray behavior. In this work, we review the main properties of the submerged electrosprays in liquid baths with no surfactant, and we methodically study the behavior of the system for increasing surfactant concentrations. The different regimes found are then analyzed and compared with both classical and more recent experimental, theoretical and numerical studies. A very rich phenomenology is found when the surface tension is allowed to vary in the system. More concretely, the lower states of electrification achieved with the reduced surface tension regimes might be of interest in biological or biomedical applications in which excessive electrification can be hazardous for the encapsulated entities.  相似文献   

The effect of scholar collaboration on impact and quality of academic papers     

Massimo Franceschet  Antonio Costantini 《Journal of Informetrics》2010,4(4):540-553

We study how scholar collaboration varies across disciplines in science, social science, arts and humanities and the effects of author collaboration on impact and quality of co-authored papers. Impact is measured with the aid of citations collected by papers, while quality is determined by the judgements expressed by peer reviewers. To this end, we take advantage of the dataset provided by the first-ever national research assessment exercise of Italian universities, which involved 20 disciplinary areas, 102 research structures, 18,500 research products, and 6661 peer reviewers. Collaboration intensity neatly varies across disciplines: it is inescapable is most sciences and negligible in most humanities. We measured a general positive association between cardinality of the author set of a paper and citation count as well as peer quality of the contribution. The correlation is stronger when the affiliations of authors are heterogeneous. There exist, however, notable and interesting counter-examples.  相似文献   

Telematics for Teacher Education: issues from a European conference     

Antonio Jose Osorio 《Technology, Pedagogy and Education》2013,22(2):183-195

ABSTRACT

The world Information Superhighway is under discussion in many countries. Within Europe the discussion is also very active as is the promotion of the use of telematics for trans‐European communication and co‐operation in various areas. For education and training, representatives of European teacher trainers, teachers, students, parents, policy and decision makers discussed their needs and views on a trans‐European network at a conference held in May 1994 in Luxembourg. This paper presents a selection of various issues raised at the conference regarding the use of telematics for teacher education and illustrates the discussion and the method of discussion. It also describes and discusses the conference programme model, as it offered innovative on‐line activities to facilitate appreciation of telematics. The case is argued that teacher education can benefit greatly from telematics and some points are put forward for further discussion.  相似文献   

Visual function,performance, and processing of basketball players vs. sedentary individuals     

Jesús Vera  Raimundo Jimnez  David Crdenas  Beatriz Redondo  Jos Antonio García 《运动与健康科学(英文)》2020,9(6):587-594

BackgroundAthletes tend to have better visuo-motor performance than do sedentary individuals. However, several basic visual-function and perceptual parameters remain unexplored to date. In this study, we investigated whether differences exist in visual function, performance, and processing between basketball players and individuals without a sport-involvement background.MethodsA total of 33 healthy men with no visual impairment or pathology were divided into 2 groups, depending on the involvement in sport (semi-professional basketball players and sedentary individuals). We tested their baseline heart-rate variability in the resting position apart from subjective questionnaires to determine their physical fitness level, and we checked their visual function, performance, and processing through an extended battery of optometric tests.ResultsThe 2 groups differed in resting heart-rate variability parameters (p < 0.001), confirming their dissimilarities in regular time practising sports per week. The basketball players showed a closer breakpoint and recovery nearpoint of convergence, a higher fusional-vergence rate, better discriminability halos, and better eye–hand coordination (all p values < 0.05).ConclusionThese results show evidence that athletes, basketball players in this case, exhibit better performance in several visual abilities in comparison to a group of individuals without sporting backgrounds, suggesting an improvement due to the systematic involvement of those skills during basketball practice.  相似文献   

The media construction of the sports’ elite from the European perspective: an analysis of the European Symposium of Sports 2010     

David Moscoso Sánchez  Antonio Pérez Flores 《Sport in Society》2018,21(3):516-528

Since the first Olympic Games, the figure of the athlete has roused enormous passion. One may wonder if nowadays the cultural mechanisms that produce them are analogous and perform the same functions as in the past. This article aims to answer these questions. For this purpose, we have relied on the analysis of the discourse from different actors in the 2010 European Symposium of Sports “Thinking Sports, Transforming Society: The EU in favor of citizenship for the XXI Century”. The results will provide relevant information about the responsibility of the mass media in the production of a sports spectacle, the role of the big brands and the exemplarity of the sports’ elite. In this manner, the need was conveyed of producing a different view of sports, so that in the contest between humanistic values and materialistic values, those who contribute to the welfare of the citizens could achieve glory.  相似文献   

Evolution and Creationism: Views of Students in a Colombian University—Findings from 7 Years of Data Using a Three-Question Survey     

Archila  Pablo Antonio  Molina  Jorge 《Research in Science Education》2020,50(4):1619-1638

Research in Science Education - The theory of evolution is the backbone of the biological sciences. Arguably, this is the reason why evolution education is an extensively investigated issue in...  相似文献   

Towards Covid-19 Literacy     

Archila  Pablo Antonio  Danies  Giovanna  Molina  Jorge  Truscott de Mejía  Anne-Marie  Restrepo  Silvia 《Science & Education》2021,30(4):785-808

Covid-19 literacy, induced by the coronavirus disease (2019), is characterized as the understanding of Covid-19 as well as informed decisions based upon this understanding. This type of literacy is closely related to health literacy, scientific literacy, and scientific media literacy. It may be obvious to say that Covid-19 literacy is a key factor for governments to effectively manage the Covid-19 transition. However, lack of literature exists about Covid-19 literacy among university students. Therefore, the current study aimed to determine the Covid-19 literacy level among 4168 students from a Colombian university. The data were derived from students’ responses to a 25–item anonymous online self-reporting questionnaire. We found that 21–25-year age group, graduate students,?students enrolled prior to 2015, and medical students had a significantly higher mean score. Moreover, the Internet (86.8%) was the most popular source of information from which participants gained most information regarding Covid-19. Furthermore, 58.5% of the participants considered health workers as a source that can provide accurate information. Most importantly, the findings reveal the students’ knowledge about (1) the role of an eventual process of vaccination, (2) the test currently used as diagnostic for Covid-19, and (3) the fatality rate, three aspects of Covid-19 literacy that deserve more attention. The findings provide a useful basis for the formulation of policies and concrete actions in improving Covid-19 literacy.

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The role of metaethics and the future of computer ethics     

Antonio Marturano 《Ethics and Information Technology》2002,4(1):71-78

In the following essay, I will discuss D.Johnson's argument in her ETHICOMP99 KeynoteSpeech (Johnson 1999) regarding the possiblefuture disappearance of computer ethics as anautonomous discipline, and I will analyze somelikely objections to Johnson's view.In the future, there are two ways in whichcomputer ethics might disappear: (1) therejection of computer ethics as an aspect ofapplied ethics, or (2) the rejection ofcomputer ethics as an autonomous discipline.The first path, it seems to me, would lead tothe death of the entire field of appliedethics, while the second path would lead onlyto the death of computer ethics as a separatesubject. Computer technology is becoming very pervasive,and each scientific field includes somediscipline-specific computing. For the likelyforeseeable future, disciplines such asbioethics and engineering ethics will have todeal with ethical issues involving the role ofcomputers. I will argue that computer ethics inthis sense is unlikely to disappear, even ifcomputer ethics ceases to be considered as aseparate discipline.In order to understand which path will befollowed by computer ethics, I will compareJohnson's argument with ideas of earlierthinkers like N. Wiener (1950) and B. Russell(1932). Although Russell did not specificallyconsider computer technology, he had somegood intuitions about the development ofsocieties by means of technology.My conclusion will be two-fold: (1) thatapplied ethics will not die, but it may make nosense in the future to talk about computerethics as a separate field; and (2) thatcomputer ethics will not simply become``ordinary ethics', contrary to Johnson's view.  相似文献   

Prospective Primary Teachers’ Prior Experiences,Conceptions, and Pedagogical Valuations of Experimental Activities in Science Education     

Antonio García-Carmona  Ana M. Criado  Marta Cruz-Guzmán 《International Journal of Science and Mathematics Education》2018,16(2):237-253

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Shared thinking: Concept and assessment     

Antonio Aguilera 《European Journal of Psychology of Education - EJPE》2001,16(2):283-298

The aim of this article is to present the Procedure for the Assessment of Thinking in Interaction (PAT), an instrument for the assessment of shared thinking. Following an introduction of our concept or “shared thinking”, such as appears in contexts of interaction, we present the results and conclusions obtained from its use in a cross-sectional and a longitudinal developmental study.  相似文献