1,725,667 research outputs found
Pteris trifoliolata (Pteridaceae), a new brake fern species from karst area in Guangxi, China
No full textWei, Hong-Jin, Liang, Yong-Yan (2022): Pteris trifoliolata (Pteridaceae), a new brake fern species from karst area in Guangxi, China. Phytotaxa 567 (1): 100-104, DOI: 10.11646/phytotaxa.567.1.10, URL: http://dx.doi.org/10.11646/phytotaxa.567.1.1
FIGURE 2. Pteris trifoliolata.—A. Habit.—B in Pteris trifoliolata (Pteridaceae), a new brake fern species from karst area in Guangxi, China
No full textFIGURE 2. Pteris trifoliolata.—A. Habit.—B. Portion of sterile pinna.—C. Portion of fertile pinna.Published as part of Wei, Hong-Jin & Liang, Yong-Yan, 2022, Pteris trifoliolata (Pteridaceae), a new brake fern species from karst area in Guangxi, China, pp. 100-104 in Phytotaxa 567 (1) on page 102, DOI: 10.11646/phytotaxa.567.1.10, http://zenodo.org/record/713787
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
Development of particle maipulation and analysis tool for microfluidic device using dielectrophoresis / Wee Wei Hong
Full text linkManipulation and analysis of microparticles in a microfluidic device finds wide application in numerous fields such as application in microbiology, drug and medicine assessment, point-of-care for disease diagnosis and microengineering. Different microfluidic devices were designed and developed to meet the needs for every application based on different engineering practices. The principle of electro-kinetics has had great impact in application to particle manipulation as it attempts to move, assembly, rotate, or separate different types of particles by changing their electrical fields. Many types of electro-kinetics are used in particle manipulation such as electrolysis, electro-osmosis, capillary osmosis, diffusiophoresis, dielectrophoresis, and sedimentation potential. In this study, I focus on the application of dielectrophoresis in manipulation of microparticles on a microfluidic device. Microfluidic chips based on a dielectrophoresis (DEP) technique hold several advantages for microparticle manipulation, such as fast result processing, instant deployment of parameters involved, a small amount of sample required, high spatial resolution, and high accuracy of target selection. Conventional dielectrophoresis techniques such as travelling wave DEP, insulative DEP and 2-dimension DEP were studied and compared with the current study in terms of the ease of fabrication, materials used and ease of access. However, there is an unmet need to develop DEP microfluidic chips on different substrates for different applications in a low cost, facile, and rapid way. For example, most existing DEP microfluidic chip fabrication methods are limited to certain substrate materials such as the photolithography technique, which applies primarily to glass, rather than being adaptable. Further, disposable DEP microfluidic devices are preferred due to the potential issues of electrode damage and sample contamination as induced by the electrolyte electrolysis process on the electrode surface in the DEP procedure. This study develops a new facile and low cost method based on a screen-printing technique for fabrication of electrodes of DEP chips on both solid/soft and transparent/non-transparent substrates (i.e., polymethyl-methacrylate (PMMA), poly(ethylene terephthalate) (PET) and A4 paper intended to provide a good base to enhance electro-kinetic devices as research continues. The fabricated PMMA-based DEP microfluidic chip was selected as an example and successfully used to trap and align polystyrene (PS) microparticles in a suspension and cardiac fibroblasts in a cell culture solution, proving the feasibility of the fabricated DEP microfluidic chip for both microparticle and biological cell trapping . The capability of the developed electrode fabrication method shows its compatibility with different kinds of DEP substrates, which could expand the future application field of DEP microfluidic chips, including new forms of point-of-care diagnostics and trapping circulating tumor cells
Investigations of air-water multiphase flow in tubes: Computational fluid dynamics / Goo Wei Hong
Full text linkMixing is a very crucial process in many industries, such as food processing industry, minerals processing industry, petrochemicals and refining industry, pulp and paper industry, polymer industry, pharmaceuticals industry and many more. There are different types of mixing, such as liquid-gas mixing, liquid-liquid mixing, solid-liquid mixing and many more. The definition of multiphase flow is the simultaneous flow of materials with multiple thermodynamic phases. A lot of process industries require multiphase flows during operation. Bubbly flow is defined as the flow of liquids that contains dispersed gas bubbles. One of the main applications of multiphases flows and bubbly flows is static mixer. The experimental and simulation studies on multiphase flows, especially bubbly flows are not widely performed due to due to several constraints. Therefore, the focus of this research project is on investigating bubbly flow using Computational Fluid Dynamics (CFD) software. The three most common multiphase models in FLUENT are Volume of Fluid (VOF) model, Mixture model and Eulerian model. The two most common models under Eulerian multiphase model in simulating bubbly flow are Population Balance Model (PBM) and Interfacial Area Concentration (IAC) model. The PBM and IAC model are compared with an available case study from ANSYS in simulating bubbly flow in a 2D vertical bubble column reactor. It is found that the simulation results obtained using PBM compared to IAC model, such as air volume fraction contours, water velocity vectors, air bin 0 fraction contours, graphs of air bin 3 fraction versus X direction at the centre of the 2D vertical bubble column reactor, discrete size 3 fraction of air contours, Sauter mean diameter of air contours and Sauter mean diameter distribution of air histograms have higher similarity with the results from the case study, but there exist some differences between the results. Not only that, the bubbly
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flow in 2D horizontal pipe is studied by manipulating the ratio of air velocity to water velocity (AV/WV) using PBM. It is found that the air volume fraction in the 2D horizontal pipe decreases when the AV/WV ratio decreases from 1. It is found that the air bubbles migrate towards the top wall of the 2D horizontal pipe almost instantly when the ratio of AV/WV is higher than 1 due to the larger buoyancy force whereas the air bubbles tend to travel the furthest at the centre of the 2D horizontal pipe before migrating to the top wall when the ratio of AV/WV is 1. However, the distance the air bubbles travel at the centre of the 2D horizontal pipe reduces if the AV/WV ratio decreases from 1. Lastly, CFD simulation of air-water multiphase flow in 3D Kenics static mixer is performed using VOF multiphase model by manipulating the volume fraction of air at the inlet. It is found that the mixing characteristics of the 3D Kenics static mixer are almost similar for the different volume fractions of air at the air inlet. However, reversed flow of water occurs due to the pressure-outlet boundary conditions at the outlets
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