917 resultados para Critical point
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In this paper, 36 English and 38 Spanish news articles were selected from English and Spanish newspapers and magazines published in the U.S.A. from August 2014 to November 2014. All articles discuss the death of Michael Brown, the ensuing protests and police investigations. A discourse analysis shows that there are few differences between reporting by the mainstream and the Hispanic media. Like the mainstream media, the Hispanic media adopts a neutral point of view with regard to the African-American minority. However, it presents a negative opinion with regard to the police. It appears that the Hispanic media does not explicitly side with the African-American community, but rather agrees more with the mainstream media’s opinion and is substantially influenced by it.
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Copyright history has long been a subject of intense and contested enquiry. Historical narratives about the early development of copyright were first prominently mobilised in eighteenth century British legal discourse, during the so-called Battle of the Booksellers between Scottish and London publishers. The two landmark copyright decisions of that time – Millar v. Taylor (1769) and Donaldson v. Becket (1774) – continue to provoke debate today. The orthodox reading of Millar and Donaldson presents copyright as a natural proprietary right at common law inherent in authors. Revisionist accounts dispute that traditional analysis. These conflicting perspectives have, once again, become the subject of critical scrutiny with the publication of Copyright at Common Law in 1774 by Prof Tomas Gomez-Arostegui in 2014, in the Connecticut Law Review ((2014) 47 Conn. L. Rev. 1) and as a CREATe Working Paper (No. 2014/16, 3 November 2014).
Taking Prof Gomez-Arostegui’s extraordinary work in this area as a point of departure, Dr Elena Cooper and Professor Ronan Deazley (then both academics at CREATe) organised an event, held at the University of Glasgow on 26th and 27th March 2015, to consider the interplay between copyright history and contemporary copyright policy. Is Donaldson still relevant, and, if so, why? What justificatory goals are served by historical investigation, and what might be learned from the history of the history of copyright? Does the study of copyright history still have any currency within an evidence-based policy context that is increasingly preoccupied with economic impact analysis?
This paper provides a lasting record of these discussions, including an editorial introduction, written comments by each of the panelists and Prof. Gomez-Arostegui and an edited transcript of the Symposium debate.
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Copyright history has long been a subject of intense and contested enquiry, and has once again become the subject of critical scrutiny with the publication of "Copyright at Common Law in 1774" by Prof Tomas Gomez-Arostegui in the Connecticut Law Review ((2014) 47 Conn. L. Rev. 1).
This online resource documents two events organised to explore the impact of "Copyright at Common Law in 1774". It incorporates a public lecture by Prof Gomez-Arostegui, and the full record of a one-day symposium of international experts debating the implications of Gomez-Arostegui's scholarship in this domain.
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Introduction: Point-of-care ultrasound (POCUS) use in clinical care is growing rapidly, and advocates have recently proposed the integration of ultrasound into undergraduate medical education (UME). The evidentiary basis for this integration has not been evaluated critically or systematically. In this study, we conducted a critical and systematic review framed by the rationales enumerated by advocates of ultrasound in UME in academic publications.
Methods: This research was conducted in two phases. First, the dominant discursive rationales for the integration of ultrasound in UME were identified using techniques from Foucauldian critical discourse analysis (CDA) from an archive of 403 academic publications. We then sought empirical evidence in support of theses rationales, using a critical synthesis methodology also adapted from CDA.
Results: We identified four dominant discursive rationales, with different levels of evidentiary support. Ultrasound was not demonstrated to improve students’ understanding of anatomy. The benefit of ultrasound in teaching physical examination was inconsistent,and rests on minimal evidence. With POCUS, students’ diagnostic accuracy was improved for certain pathologies, but findings were inconsistent for others. Finally, the rationale that ultrasound training in UME will improve quality of patient care was difficult to evaluate.
Discussion: Our analysis has shown that the frequently repeated rationales for the integration of ultrasound in UME are not supported by a sufficient base of empirical research. The repetition of these dominant discursive rationales in academic publications legitimizes them and may preclude further primary research. Since the value of clinical ultrasound use by medical students remains unproven, educators must consider whether the associated financial and temporal costs are justified or whether more research is required.
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This article is an introductory note to The thematic section in this issue of Education Inquiry has its background in the need for research interpreting literacy from a critical perspective. Teaching literacy is not solely about technical reading skills but is also about understanding and the making of meaning. From that point of view, teaching must also consider the use of language, the context within which language is used, and issues of power. The thematic section includes five articles about critical literacy in Swedish education. The contributions were developed after a workshop conducted by Professor Hilary Janks, University of the Witwatersrand, Johannesburg. She introduces the framework of a critical literacy theory in the first article of the issue. Further, the contributions of Swedish scholars are united in their interest in applying a mode of critical literacy designed by Janks to different practices, sites and speech-events, for example policy documents, home reading, teaching and learning practices. The articles offer a wide perspective of critical literacy in education and further understanding of the complex processes in teaching.
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The purpose of this paper is to use the framework of Lie algebroids to study optimal control problems for affine connection control systems (ACCSs) on Lie groups. In this context, the equations for critical trajectories of the problem are geometrically characterized as a Hamiltonian vector field.
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In this thesis the critical dynamics of several magnetoelectric compounds at their phase transition were examined. Mostly measurements of the dielectric properties in the frequency range of below 1 Hz up to 5 GHz were employed to evaluate the critical exponents for both magnetic field and temperature-dependent measurements. Most of the materials that are part of this work show anomalous behavior, especially at very low temperatures where quantum fluctuations are of the order of or even dominate those induced thermally. This anomalous behavior manifests in different forms. In Dy2Ti2O7 we demonstrate the existence of electric dipoles on magnetic monopoles. Here the dynamics at the critical endpoint located at 0.36K and in a magnetic field of 1T parallel to the [111] direction are of special interest. At this critical endpoint the expected critical slowing down of the dynamics could not only not be observed but instead the opposite, critical speeding-up by several orders of magnitude, could be demonstrated. Furthermore, we show that the phase diagram of Dy2Ti2O7 in this field direction can be reproduced solely from the dynamical properties, for example the resonance frequency of the observed relaxation that is connected to the monopole movement. Away from this point of the phase diagram the dynamics are slowing-down with reduction of temperature as one would expect. Additional measurements on Y2Ti2O7, a structurally identical but non-magnetic material, show only slowing down with reduction of temperature and no additional features. A possible explanation for the observed critical speeding-up is a coherent movement of magnetic monopoles close to the critical field that increases the resonance frequency by reducing the damping of the process. LiCuVO4 on the other hand behaves normally at its phase transition as long as the temperature is higher than 0.4 K. In this temperature regime the dynamics show critical slowing-down analogous to classical ferroelectric materials. This analogy extends also towards higher frequencies where the permittivity displays a ‘dispersion’ minimum that is temperature-dependent but of the order of 2 GHz. Below 0.4K the observed behavior changes drastically. Here we found no longer relaxational behavior but instead an excitation with very low energy. This low energy excitation was predicted by theory and is caused by nearly gapless soliton excitations within the 1D Cu2+ chains of LiCuVO4. Finally, in TbMnO3 the dynamics of the phase transition into the multiferroic phase was observed at roughly 27 K, a much higher temperature compared to the other materials. Here the expected critical slowing-down was observed, even though in low-frequency measurements this transition into the ferroelectric phase is overshadowed by the so-called c-axis relaxation. Therefore, only frequencies above 1MHz could be used to determine the critical exponents for both temperatureand magnetic-field-dependent measurements. This was done for both the peak frequency as well as the relaxation strength. In TbMnO3 an electromagnetic soft-mode with small optical weight causes the observed fluctuations, similar to the case of multiferroic MnWO4.
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This thesis is devoted to the development, synthesis, properties, and applications of nano materials for critical technologies, including three areas: (1) Microbial contamination of drinking water is a serious problem of global significance. About 51% of the waterborne disease outbreaks in the United States can be attributed to contaminated ground water. Development of metal oxide nanoparticles, as viricidal materials is of technological and fundamental scientific importance. Nanoparticles with high surface areas and ultra small particle sizes have dramatically enhanced efficiency and capacity of virus inactivation, which cannot be achieved by their bulk counterparts. A series of metal oxide nanoparticles, such as iron oxide nanoparticles, zinc oxide nanoparticles and iron oxide-silver nanoparticles, coated on fiber substrates was developed in this research for evaluation of their viricidal activity. We also carried out XRD, TEM, SEM, XPS, surface area measurements, and zeta potential of these nanoparticles. MS2 virus inactivation experiments showed that these metal oxide nanoparticle coated fibers were extremely powerful viricidal materials. Results from this research suggest that zinc oxide nanoparticles with diameter of 3.5 nm, showing an isoelectric point (IEP) at 9.0, were well dispersed on fiberglass. These fibers offer an increase in capacity by orders of magnitude over all other materials. Compared to iron oxide nanoparticles, zinc oxide nanoparticles didn’t show an improvement in inactivation kinetics but inactivation capacities did increase by two orders of magnitude to 99.99%. Furthermore, zinc oxide nanoparticles have higher affinity to viruses than the iron oxide nanoparticles in presence of competing ions. The advantages of zinc oxide depend on high surface charge density, small nanoparticle sizes and capabilities of generating reactive oxygen species. The research at its present stage of development appears to offer the best avenue to remove viruses from water. Without additional chemicals and energy input, this system can be implemented by both points of use (POU) and large-scale use water treatment technology, which will have a significant impact on the water purification industry. (2) A new family of aliphatic polyester lubricants has been developed for use in micro-electromechanical systems (MEMS), specifically for hard disk drives that operate at high spindle speeds (>15000rpm). Our program was initiated to address current problems with spin-off of the perfluoroether (PFPE) lubricants. The new polyester lubricant appears to alleviate spin-off problems and at the same time improves the chemical and thermal stability. This new system provides a low cost alternative to PFPE along with improved adhesion to the substrates. In addition, it displays a much lower viscosity, which may be of importance to stiction related problems. The synthetic route is readily scalable in case additional interest emerges in other areas including small motors. (3) The demand for increased signal transmission speed and device density for the next generation of multilevel integrated circuits has placed stringent demands on materials performance. Currently, integration of the ultra low-k materials in dual Damascene processing requires chemical mechanical polishing (CMP) to planarize the copper. Unfortunately, none of the commercially proposed dielectric candidates display the desired mechanical and thermal properties for successful CMP. A new polydiacetylene thermosetting polymer (DEB-TEB), which displays a low dielectric constant (low-k) of 2.7, was recently developed. This novel material appears to offer the only avenue for designing an ultra low k dielectric (1.85k), which can still display the desired modulus (7.7Gpa) and hardness (2.0Gpa) sufficient to withstand the process of CMP. We focused on further characterization of the thermal properties of spin-on poly (DEB-TEB) ultra-thin film. These include the coefficient of thermal expansion (CTE), biaxial thermal stress, and thermal conductivity. Thus the CTE is 2.0*10-5K-1 in the perpendicular direction and 8.0*10-6 K-1 in the planar direction. The low CTE provides a better match to the Si substrate which minimizes interfacial stress and greatly enhances the reliability of the microprocessors. Initial experiments with oxygen plasma etching suggest a high probability of success for achieving vertical profiles.
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Ethos is the spirit that motivates ideas and practices. When we talk casually about the ethos of a town, state, or country we are describing the fundamental or at least underlying rationale for action, as we see it. Ideology is a way of looking at things.It is the set of ideas that constitute one’s goals, expectations, and actions. In this brief essay I want to create a space where we might talk about the ethos and ideology in knowledge organization from a particular point of view; combining ideas and inspiration from the Arts and Crafts movement of the early Twentieth Century, critical theory in extant knowledge organization work, the work of Slavoj Žižek, and the work of Thich Nhat Hahn on Engaged Buddhism.I will expand more below, but we can say here and now that there are many open questions about ethos and ideology in and of knowledge organization, both its practice and products. Many of them in classification, positioned as they are around identity politics of race, gender, and other marginalized groups, ask the classificationist to be mindful of the choice of terms and relationships between terms. From this work we understand that race and gender requires special consideration, which manifests as a particular concern for the form of representation inside extant schemes. Even with these advances in our understanding there are still other categories about which we must make decisions and take action. For example, there are ethical decisions about fiduciary resource allocation, political decisions about standards adoption, and even broader zeitgeist considerations like the question of Fordist conceptions (Day, 2001; Tennis 2006) of the mechanics of description and representation present in much of today’s practice.Just as taking action in a particular way is an ethical concern, so too is avoiding a lack of action. Scholars in Knowledge Organization have also looked at the absence of what we might call right action in the context of cataloguing and classification. This leads to some problems above, and hints at larger ethical concerns of watching a subtle semantic violence go on without intervention (Bowker and Star, 2001; Bade 2006).The problem is not to act or not act, but how to act or not act in an ethical way, or at least with ethical considerations. The action advocated by an ethical consideration for knowledge organization is an engaged one, and it is here where we can take a nod from contemporary ethical theory advanced by Engaged Buddhism. In this context we can see the manifestation of fourteen precepts that guide ethical action, and warn against lack of action.
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The concept of cultural cannibalism was discussed and re-established by intellectuals from the field of literary and cultural criticism, and it was also the object of creative appropriation by a significant group of writers in Brazil and in the Latin America context. Nevertheless, this concept is revitalized in the contemporary context, reflecting the critical consciousness of the writer on the understanding of social inequalities that shape Latin America, in its different segments, be they political, economic or cultural.
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In this article, the author discusses how she applied autoethnography in a study of the design of hypermedia educational resources and shows how she addressed problematic issues related to autoethnographic legitimacy and representation. The study covered a 6-year period during which the practitioner’s perspective on the internal and external factors influencing the creation of three hypermedia CD-ROMs contributed to an emerging theory of design. The author highlights the interrelationship between perception and reality as vital to qualitative approaches and encourages researchers to investigate their reality more fully by practicing the art of autoethnography.