6,440 research outputs found
The response of smoke detectors to pyrolysis and combustion products from aircraft interior materials
The following projects were completed as part of the effort to develop and test economically feasible fire-resistant materials for interior furnishings of aircraft as well as detectors of incipient fires in passenger and cargo compartments: (1) determination of the sensitivity of various contemporary gas and smoke detectors to pyrolysis and combustion products from materials commonly used in aircraft interiors and from materials that may be used in the future, (2) assessment of the environmental limitations to detector sensitivity and reliability. The tests were conducted on three groups of materials by exposure to the following three sources of exposure: radiant and Meeker burner flame, heated coil, and radiant source only. The first test series used radiant heat and flame exposures on easily obtainable test materials. Next, four materials were selected from the first group and exposed to an incandescent coil to provide the conditions for smoldering combustion. Finally, radiant heat exposures were used on advanced materials that are not readily available
Using Concept Maps to improve Scientific Communications
Scientic talks, like scientic papers, are an important part of the scientic communication process. Good oral presentation skills, are vital to educational sciences, as well as to many other fields. In the engineering community, such presentations offer, a quick outline of project proposals and progress reports. In the academic community,
the ability to clearly transmit scientic information, in an oral presentation, is critical to both teaching and research. Over the last years, it has become apparent, to many educational researchers, that representing knowledge, in a visual format, allows one to better recognize and
understand, incoming information. Since Novak, placed concept mapping on the educational agenda, it has become an increasingly popular advanced teaching and learning tool. Due mainly to the innovation of visual design software like CmapTool, the production and modication of Concept Maps is straightforward. While there are no strict rules about how to give a motivating and compelling presentation, there are some guiding principles which are easy to grasp and apply. The modern scientist must be able to create well organized, well delivered scientic talks. In this context, Concept Maps harness the power of our vision to understand complex information. We propose some ideas and resources based, on the use of concept maps to make the process of preparing and organizing good talks easier. In essence, good scientic talks must satisfy the following three goals: to connect with the audience, to direct and hold attention, and to promote understanding and memory. To accomplish these goals talk material must be elaborated carefully and logically. The plan to achieve them should have four parts: preparation, structure, design, and exposition. We focus our work on the first two parts of the plan, and supply some helpful guidelines on efective ways to prepare the scientic information, using conceptual maps with the software CmapTool
The strong global dimension of piecewise hereditary algebras
Let T be a tilting object in a triangulated category equivalent to the
bounded derived category of a hereditary abelian category with finite
dimensional homomorphism spaces and split idempotents. This text investigates
the strong global dimension, in the sense of Ringel, of the endomorphism
algebra of T. This invariant is expressed using the infimum of the lengths of
the sequences of tilting objects successively related by tilting mutations and
where the last term is T and the endomorphism algebra of the first term is
quasi-tilted. It is also expressed in terms of the hereditary abelian
generating subcategories of the triangulated category.Comment: Final published version. After refereeing, historical considerations
were added and the length of the article was reduced: Introduction and
Section 1 were reformulated; Subsection 2.1 was moved to Section 1 (with an
abridged proof); Subsection 3.2 was reformulated (with an abridged proof);
The proof in A.5 was rewritten (now shorter); And minor rewording was
processed throughout the articl
XLIII Conferências de Genética Doutor Jacinto Magalhães: resumo das comunicações
Suplemento da revista Nascer & Crescer com os resumos dos Posters e Comunicações orais apresentadas durante as XLIII Conferências de Genética Doutor Jacinto Magalhães que decorreu no dia 28 de março de 2014, na cidade do Porto, Portuga
Hipertensão pulmonar na criança o que há de novo?: Resumo das comunicações
Suplemento da revista Nascer & Crescer com os resumos das Comunicações Livres apresentadas durante a Reunião CientÃfica "Hipertensão pulmonar na criança: o que há de novo?" que decorreu no dia 13 de junho de 2014, na cidade do Porto, Portuga
XXVI Reunião de Pediatria do CMIN-CHP: Resumo das comunicações
Suplemento da revista Nascer & Crescer com os resumos dos Posters e Comunicações orais apresentadas durante a XXVI Reunião Anual de Pediatria CMIN – CHP que decorreu entre os dias 28 e 29 de novembro de 2014, na cidade do Porto, Portuga
Holography of the Conformal Window
Inspired by the model of Jarvinen and Kiritsis, we present a simple
holographic model for the on set of chiral symmetry breaking at the edge of the
conformal window in QCD in the Veneziano limit. Our most naive model enforces
the QCD two loop running coupling on a D3/D7 holographic brane system. The mass
of the holographic field, describing the chiral condensate in the model, is
driven below the BF bound when the running is sufficiently strong, triggering
chiral symmetry breaking for N_f/N_c<2.9. This model though contains too great
a remnant of supersymmetry and does not correctly encode the perturbative
anomalous dimensions of QCD. In a second model we impose the QCD anomalous
dimension result and find chiral symmetry breaking sets in for N_f/N_c=4 at a
BKT-type phase transition. In this case the transition is triggered when the
anomalous dimension of the mass operator \gamma_m=1.Comment: 10 pages, 2 figures, v2: minor corrections, improved Figure
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