323,402 research outputs found
A Multiscale Approach for the Characterization and Crystallization of Eflucimibe Polymorphs: from Molecules to Particles
No full textWe present in this paper a generic multiscale methodology for the characterization and crystallization of eflucimibe polymorphs. The various characterization techniques used have shown that eflucimibe polymorphism is due to a conformational change of the molecule in the crystal lattice. In addition, the two polymorphs are monotropically related in the temperature range tested and have similar structures and properties (ie. interfacial tension and solubility). Consequently, it was found that for a wide range of operating conditions, the polymorphs may crystallize concomitantly. Induction time measurements and metstable zone width determination allow to infer the origin of the concomitant appearance of the polymorphs. A predominance diagram has been established which allows to perfectly control the crystallization of the desired polymorph. However, even if the stable form can be produced in a reliable way, the crystal suspension went toward a very structured gel-like network which limits the extrapolation process. Based on microscopic observation of the crystallization events performed in a microfluidic crystallizer, we propose a range of operating conditions suitable for the production of the stable form with the desired handling properties
Crystal nucleation in adroplet based microfluidic crystallizer
No full textThe study presented in this paper deals with the determination of eflucimibe nucleation rate in a droplet based microfluidic crystallizer. The experimental device allows the storage of up to 2000 monodispersed droplets to get nucleation statistics and crystal growth rates under static conditions. Supersaturation was generated by quenching the droplets down to 273 or 293 K. To determine the nucleation kinetics of eflucimibe, the number of appearing crystals is recorded as a function of time. At low time scale, it was found that eflucimibe in the droplets containing active centers (impurities) crystallizes first and thus yields a rapid initial rate. At higher time scale, once all the droplets containing impurities have crystallized, leaving only the droplets that are free of impurities, the nucleation rate falls allowing the determination of the homogeneous nucleation rate. The crystal–solution interfacial energy found in this system σ=3.12 mJ m−2 is in good agreement with the previously published results. Using the crystalnucleation and the growth rate determined experimentally, simulations were performed using a Monte Carlo method. Even if this method correctly predicts the number of droplets that remains empty during the experiments, it was not possible to predict correctly the number of crystals per drop obtained experimentally. The relationship between the growth and nucleation rates and the resultant number of crystals per drop is likely to be complex and dependent on a number of system parameters. The failure of the model may be attributed either to an overestimation of the crystal growth rate or to an enhancement of the nucleation rate due to the presence of seed crystals
Diffusive author(s), cohesive author: Analysis of S/N (1994)
No full textThis study indicates the ways in which various aspects of the author(s) are brought forth in Dumb type’s performance art, the S/N production. Previous research has suggested a non-hierarchical organization of Dumb type and the absence of a “privileged author” in Dumb type’s collaborative work, S/N. However, the results that I have investigated from member’s interviews on the creative process of S/N along with my analysis of the recorded images of S/N, indicate a different aspect of the author(s). First, S/N was created through, so to speak, the collective ideas of the members of Dumb type. Further, S/N has at least nine quotations from previous performances, installations, and printed writings, besides the work-in-progress technique. Explicating one of the “author functions” as given by Michel Foucault, each text has plural subjects of the author. However, it has been revealed from members’ interviews that Teiji Furuhashi had a decision-making role in selecting the members’ ideas within the performance. Since then, S/N has had plural subjects of creation; however, Furuhashi is one of the subjects of creation along with the “privileged author.” S/N has plural authors (diffusive authors) yet at the same time, it has a “privileged author,” Teiji Furuhashi (cohesive author)
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
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No full textCan archives of audiovisual TV interviews be used to make authors more visible to students, and thereby reduce the learning gap between native and non-native language speakers in college classes? We examined students in a college course who learned about one scholar's ideas through watching an audiovisual TV interview (i.e., visible author format) and about another scholar's ideas through reading a formal text description (i.e., invisible author format). For the invisible author, native language speakers scored significantly higher than the non-native language speakers on a corresponding exam question (i.e., a cognitive measure), generated more words on the exam question (i.e., a motivational measure), and mentioned the author's name more often in answering the exam question (i.e., an affective measure). For the visible author, the groups did not differ on any of these measures. These findings provide evidence for the idea that making the author visible through audiovisual TV interviews can eliminate the learning gap between native and non-native language speakers. 3 Universities around the world serve students who are non-native speakers of th
The vanishing author in computer-generated works: a critical analysis of recent Australian case law
No full textAbstract
The use of software is ubiquitous in the creation of many copyright works, yet the requirement in copyright law that every work have a human author who engages in independent intellectual effort means that its use may prevent copyright subsistence. Several recent Australian cases have refocused attention on authorship as an essential criterion of copyright subsistence, and these cases suggest that much computer-produced output may be authorless and thus lack copyright protection. This article, the first in a two-part series, analyses how each case deals with the question of authorship of computer-produced works and why the use of software diminishes copyright protection for a significant number of computer-generated works. The article critiques the application of conventional notions of human authorship developed in the pre-computer age to modern productions and suggests alternative approaches to authorship that satisfy both the major objectives of copyright policy and the need to adapt to the computer age. The article argues that, without a broader judicial approach to authorship of computer-generated works, Parliament must remedy the lacuna in protection for these ‘authorless’ works. Possible solutions for reform are suggested. In a forthcoming article, the author comprehensively examines those reform proposals
The construction of Karen Karnak: The multi-author-function
No full textThis thesis is situated within the comparatively recent developments of Web 2.0 and the emergence of interactive WikiMedia, and explores the mode of authorship within a Read/Write culture compared to that of a Read/Only tradition. The hypothesis of this study is that the role of the audience has become merged with the author, and as such, represents new functions and attributes, distinct from a more conventional concept of authorship, in which the roles of audience and author are more separate. Read/Write and participatory culture, as defined by this study, is focused on collaboration, and includes the influences of D.I.Y. culture, Open-Source practices and the production of text by multiple authors. Multi-authorship presents a re-thinking of several concepts which support the notion of the individual author, since the focus of multi-authorship is not on attribution and ownership of a finished text, but on the continued malleability of a text. Modes of multi-authorship, demonstrated in the use of the pseudonyms Alan Smithee and Karen Eliot, represent declarative authors whose names signify multiple origins, whilst concurrently indicating a distinct body of work. The function of these names form an important context to this study, since primary research involves the construction of an experimental mode of multi-authorship utilising WikiMedia technology and the interaction of thirty nine participants, who are invited to create a body of work under the collective pseudonym Karen Karnak. The data generated by this experiment is analysed using aspects of Michel Foucault's author-function to identify and determine power structures inherent in the WikiMedia context. The interplay of power structures, including concepts such as identity, ownership and the body of work, affect the resulting mode of authorship and contribute to the construction of Karen Karnak, suggesting further areas of research into the emerging multi-author
A general framework for pellet reactor modelling : application to P-recovery
No full textEmphasis in recent years has been focused on improving processes which lead to enhanced phosphate recovery. This paper studies the precipitation features of calcium phosphate in a fluidized bed reactor in a concentration range between 4 and 50 mg l 1 and establishes the conditions for optimum phosphate removal efficiency. For this purpose, two models are coupled for predicting the pellet reactor effi ciency. First, a thermodynamical model is used for predicting calcium phosphate precipitation vs. initial conditions (pH, [P], [Ca], temperature). The second one is a reactor network model. Its parameters are identified by an optimization procedure based on simulated annealing and quadratic programming. The efficiency is computed by coupling a simple agglomeration model with a combination of elementary systems representing basic ideal flow patterns (perfect mixed flow, plug flow, etc.). More precisely, the superstructure represents the hydrodynamical conditions in the fluidized bed. The observed results show that a simple combination of ideal flow patterns is involved in pellet reactor modelling, which seems interesting for a future control. The experimental prototype used for validation purpose is first described. Then, the thermochemical model is presented for calcium phosphate precipitation. The third part is devoted to the reactor networkoriented model. The approach presented is finally validated with experimental runs
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