243 research outputs found
Stainless Steel Alloys from First-principles Theory
Gaining an accurate description of materials obviously requires the most advanced atomic-scale techniques fromboth experimental and theoretical areas. In spite of the vast number of available techniques, however, theexperimental study of the atomic-scale properties and phenomena even in simple solids is rather difficult. Insteels the challenges become more complex due to the interplay between the structural, chemical and magneticeffects. On the other hand, advanced computational methods based on density functional theory ensure a properplatform for studying the fundamental properties of steel materials from first-principles. Our group at the RoyalInstitute of Technology in Stockholm has an international position in developing and applying computationalcodes for such applications. Using our ab initio tools, we have presented an insight to the electronic andmagnetic structure, and micromechanical properties of austenitic stainless steel alloys. In the presentcontribution, we review the most important developments within the ab initio quantum-mechanics-aided steeldesign with special emphasis on the role of magnetism on the fundamental properties of alloy steels
An Imaging Survey of Early-Type Barred Galaxies
This paper presents the results of a high-resolution imaging survey, using
both ground-based and Hubble Space Telescope images, of a complete sample of
nearby barred S0--Sa galaxies in the field, with a particular emphasis on
identifying and measuring central structures within the bars: secondary bars,
inner disks, nuclear rings and spirals, and off-plane dust. A discussion of the
frequency and statistical properties of the various types of inner structures
has already been published. Here, we present the data for the individual
galaxies and measurements of their bars and inner structures. We set out the
methods we use to find and measure these structures, and how we discriminate
between them. In particular, we discuss some of the deficiencies of ellipse
fitting of the isophotes, which by itself cannot always distinguish between
bars, rings, spirals, and dust, and which can produce erroneous measurements of
bar sizes and orientations.Comment: LaTeX, 66 pages (including 42 figures, 36 in color). To appear in The
Astrophysical Journal Supplement. Full-resolution and text-only versions
available at http://www.iac.es/galeria/erwin/research
Dynamics of Barred Galaxies
Some 30% of disc galaxies have a pronounced central bar feature in the disc
plane and many more have weaker features of a similar kind. Kinematic data
indicate that the bar constitutes a major non-axisymmetric component of the
mass distribution and that the bar pattern tumbles rapidly about the axis
normal to the disc plane. The observed motions are consistent with material
within the bar streaming along highly elongated orbits aligned with the
rotating major axis. A barred galaxy may also contain a spheroidal bulge at its
centre, spirals in the outer disc and, less commonly, other features such as a
ring or lens. Mild asymmetries in both the light and kinematics are quite
common. We review the main problems presented by these complicated dynamical
systems and summarize the effort so far made towards their solution,
emphasizing results which appear secure. (Truncated)Comment: This old review appeared in 1993. Plain tex with macro file. 82 pages
18 figures. A pdf version with figures at full resolution (3.24MB) is
available at http://www.physics.rutgers.edu/~sellwood/bar_review.pd
A Protein L -Based Immunodiagnostic Approach Utilizing Time-Resolved Forster Resonance Energy Transfer
Peer reviewe
Fostering Professional Ethical Competence During Teacher Training Practice
Professionals who have undergone their training at university should possess not only the knowledge-base necessary to practice in their chosen profession, but also the ethical principles that ensure responsible professional practice and the corresponding benefits for society.
The research project addressed in the present article aimed to contribute to fostering ethical competence and commitment amongst future teachers. During the experience the participants had the opportunity to design tasks that stimulated reflection, critique and ethical awareness.Specialistai, įgiję universitetinį išsilavinimą, turi būti sukaupę ne tik žinių, kurios būtinos
profesinėje veikloje, bet ir gebėti vadovautis etikos principais, kurie užtikrintų atsakingą ir visuomenės gerovei reikalingą profesinę veiklą. Tyrime, pristatomame šiame straipsnyje, analizuojamos būsimųjų mokytojų etinės kompetencijos plėtros ir atsidavimo darbui problemos. Tyrimo
dalyviai turėjo galimybę kurti užduotis, kurios skatino refleksiją, kritiką ir etinį sąmoningumą.Les professionnels ayant reçu leur formation auprès des Universités
disposeront, non seulement des connaissances de base nécessaires à
l'exercice de leur métier, mais aussi les principes éthiques
garantissant un exercice professionnel responsable portant bénéfice sur la société. Le projet de recherche présenté sous ce titre a comme objectif la contribution à la favorisation de la compétence éthique et de l'engagement parmi les futurs enseignants. Lors de cette expérience, les participants ont eu l'occasion d'élaborer des tâches favorisant la réflexion, la critique et la pensée critique.Профессионалы, получившие университетское образование, не только получают основные знания для работы по своей профессии, но и моральные принципы, которые обеспечивают ответственную профессиональную работу и соответствующую выгоду для общества. Целью исследовательского проекта,представленного под этим именем, является участие в стимуляции профессиональной этики и компромисса среди будущих преподавателей. Во время проведения эксперимента, участники получили возможность разработать задания, стимулирующие размышление, критику и критичиское сознание.Los profesionales que han recibido su formación en la Universidad,
poseerán no solo el conocimiento base necesario para la práctica en su profesión, sino también los principios éticos que aseguran la práctica profesional responsable y el correspondiente beneficio para la sociedad. El proyecto de investigación presentado con este título tiene como objetivo contribuir a estimular la competencia ética y el compromiso
entre los futuros docentes. Durante la experiencia, los participantes
tuvieron la oportunidad de diseñar tareas que estimularan la reflexión, la crítica y la conciencia crítica
Action potentials in abscisic acid-deficient tomato mutant generated spontaneously and evoked by electrical stimulation
Action potentials generated spontaneously (SAPs) and evoked by electrical stimulation (APs) in tomato plants (Solanum lycopersicum L.) cv. Micro-Tom ABA-deficient mutants (sitiens—MTsit) and its wild type (MTwt) were characterized by continuous monitoring of electrical activity for 66 h and by application of an electrical stimulation supplied extracellularly. MTsit generated SAPs which spread along the stem, including petioles and roots with an amplitude of 44.6 ± 4.4 mV, half-time (t½) of 33.1 ± 2.9 s and velocity of 5.4 ± 1.0 cm min−1. Amplitude and velocity were 43 and 108 % higher in MTsit than in MTwt, respectively. The largest number of SAPs was registered in the early morning in both genotypes. MTsit was less responsive to electrical stimuli. The excitation threshold and the refractory period were greater in MTsit than in MTwt. After current application, APs were generated in the MTwt with 21.2 ± 2.4 mV amplitude and propagated with 5.6 ± 0.5 cm min−1 velocity. Lower intensity stimuli did not trigger APs in these plants. In MTsit APs were measured with amplitude of 26.8 ± 4.8 mV and propagated with velocity of 8.5 ± 0.1 cm min−1
Incorporation of conjugated linoleic acid (CLA) and α-linolenic acid (LNA) in pacu fillets
Comparison of proximate chemical composition and texture of cupim, Rhomboideus m. and lombo, Longissimus dorsi m. of Nelore (Bos indicus)
Solar radiation and vertical leaf area distribution in forest - Reserva Biológica do Cueiras ZF02, Manaus
In this work, the vertical leaf area distribution is investigated in connection with radiation regime, using the measurements of solar radiation made om July to November 2001 at the experimental site of Reserva Biológica do Cuieiras, Manaus, ZF2 km 14 and km 34, in Central Amazonia. A sampling technique is used for the radiation measurements inside two tall canopy covers, having a mobile support apparatus, made up of modular ame, which allows placement of the radiation sensors at different heights along a vertical line within the canopy. Inversion of the solar radiation physical model allowed a determination of the leaf area density. Spatial variability of leaf area (LAI, function a(z)) is established for the two experimental sites om the measurements of solar radiation in three verticals on each site. The average values of leaf area index (LAI) for the local vegetation at km 14 and at km 34 ZF2 were 6,4 and 6,1, respectively. A comparative analysis is developed concerning the vertical distributions of leaf area obtained for different experimental sites in Amazonia, using the same solar radiation measurement system.Neste estudo, a distribuição vertical de área foliar em floresta é investigada em conexão com o regime de radiação, usando as medidas de radiação solar realizadas no período de julho a novembro de 2001, na Reserva Biológica do Cuieiras - Manaus ZF2, km 14 e km 34, na Amazônia Central. Técnicas experimentais de amostragem de radiação no interior de coberturas vegetais de grande porte são utilizadas, com dispositivos de suporte móveis constituídos por reticulados modulares, que permitem a disposição dos sensores de radiação em diferentes níveis de uma mesma vertical no interior da cobertura. Inversão de modelos radiativos em coberturas vegetais densas permite as análises sobre a distribuição vertical de área foliar. A variabilidade espacial de área foliar (IAF, função a(z)) é estabelecida para os dois sítios experimentais a partir de medidas de radiação solar, individualizadas em três verticais em cada um desses locais. O índice de área foliar total médio (IAF) da vegetação local para o sítio experimental do km 14 alcançou o valor de 6,4 e para o sítio experimental do km 34 o valor de 6,1. Uma análise comparativa é desenvolvida sobre distribuições verticais de área foliar obtidas em sítios experimentais da Amazônia, usando o mesmo sistema de medidas de radiação solar
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