Antivivissecção na educação científica : uma proposta didática para a licenciatura em ciências biológicas

No contexto do presente trabalho, o termo vivissecção se refere a experimentos realizados com animais não humanos vivos no ensino visando observação, indução, ou constatação de fenômenos. O principal objetivo foi favorecer, através de uma estratégia didática, a construção de conceitos sobre antivivissecção pelos interlocutores da pesquisa. O trabalho foi desenvolvido durante um curso de formação ministrado a acadêmicos e professores da área de Licenciatura em Ciências Biológicas. O instrumento de coleta de dados consistiu em um questionário com questões abertas e fechadas. Os resultados chamam a atenção sobre a efetividade do planejamento e seleção adequada de recursos para a compreensão de conceitos sobre antivivissecção na Educação Científica. Também fornecem subsídios para se pensar a visão hegemônica utilitarista e especista no Ensino de Ciências

Periodic parabolic problems with nonlinearities indefinite in sign

Let Ω ⊂ RN be a smooth bounded domain. We give sufficient conditions (which are also necessary in many cases) on two nonnegative functions a, b that are possibly discontinuous and unbounded for the existence of nonnegative solutions for semilinear Dirichlet periodic parabolic problems of the form Lu =λa (x, t) u p − b (x, t) u q in Ω × R, where 0 0. In some cases we also show the existence of solutions uλ in the interior of the positive cone and that uλ can be chosen such that λ → uλ is differentiable and increasing. A uniqueness theorem is also given in the case p ≤ q. All results remain valid for the corresponding elliptic problems

On positive solutions for some semilinear periodic parabolic eigenvalue problems

AbstractFor a bounded domain Ω in RN, N⩾2, satisfying a weak regularity condition, we study existence of positive and T-periodic weak solutions for the periodic parabolic problem Luλ=λg(x,t,uλ) in Ω×R, uλ=0 on ∂Ω×R. We characterize the set of positive eigenvalues with positive eigenfunctions associated, under the assumptions that g is a Caratheodory function such that ξ→g(x,t,ξ)/ξ is nonincreasing in (0,∞) a.e. (x,t)∈Ω×R satisfying some integrability conditions in (x,t) and ∫0Tesssupx∈Ωinfξ>0g(x,t,ξ)ξdt>0

Magnetic exchange mechanism for electronic gap opening in graphene

We show within a local self-consistent mean-field treatment that a random distribution of magnetic adatoms can open a robust gap in the electronic spectrum of graphene. The electronic gap results from the interplay between the nature of the graphene sublattice structure and the exchange interaction between adatoms.The size of the gap depends on the strength of the exchange interaction between carriers and localized spins and can be controlled by both temperature and external magnetic field. Furthermore, we show that an external magnetic field creates an imbalance of spin-up and spin-down carriers at the Fermi level, making doped graphene suitable for spin injection and other spintronic applications.Comment: 5 pages, 5 figure

Using Display Energy Certificates to quantify public sector office energy consumption

This paper explores how internal and external characteristics affect energy use in the public sector office stock in England and Wales, using a database of 2,600 Display Energy Certificates (DECs) combined with other sources of disaggregated office information. The DEC office benchmarks were shown to match the median fossil thermal and electrical consumptions well. Analysis of HVAC, size, occupancy density, building age, location and rateable value were considered. While newer offices were shown to have lower typical fossil-thermal consumption than older offices, this was counterbalanced by higher electrical consumption, resulting in higher typical CO2 emissions. This has implications for the UK's emissions reduction targets for 2050, indicating that while building regulations that focus on thermal performance have been successful, a focus on electrical consumption (both regulated and unregulated) is key. The results were also compared with existing benchmarks for all UK offices, splitting the sample into four generic types, and compared to a similar smaller study of private offices. This indicated that public offices typically used less energy than the general benchmarks had previously predicted, particularly for prestige offices.This work was supported by the Engineering and Physical Sciences Research Council (EPSRC) funding for Doctoral Training Studentships, and in association with the EPSRC funded 'ReVISIONS' project [grant number EP/F007566/1].This is the final published version. It first appeared at http://dx.doi.org/10.1080/09613218.2014.97541

Potencialidades do guandu como adubação verde em áreas cultivadas com cana-de-açúcar nos tabuleiros costeiros de Alagoas.

Grande parte da produção de cana-de-açúcar em Alagoas está concentrada nos tabuleiros costeiros, região litorânea com precipitação favorável ao desenvolvimento da cultura. Contudo, os solos de tabuleiros apresentam algumas limitações agrícolas referentes à baixa resistência mecânica a operações de preparo de solo, baixa fertilidade natural e de retenção de água e nutrientes. Os solos são caracterizados ainda por apresentarem uma alta coesão natural dos horizontes, o que dificulta a penetração e desenvolvimento radicular das plantas, a disponibilidade de água, a aeração e a absorção de nutrientes, podendo influenciar negativamente no desenvolvimento das culturas.bitstream/item/123063/1/Potencialidades-do-guandu.pd

Quantum Multibaker Maps: Extreme Quantum Regime

We introduce a family of models for quantum mechanical, one-dimensional random walks, called quantum multibaker maps (QMB). These are Weyl quantizations of the classical multibaker models previously considered by Gaspard, Tasaki and others. Depending on the properties of the phases parametrizing the quantization, we consider only two classes of the QMB maps: uniform and random. Uniform QMB maps are characterized by phases which are the same in every unit cell of the multibaker chain. Random QMB maps have phases that vary randomly from unit cell to unit cell. The eigenstates in the former case are extended while in the latter they are localized. In the uniform case and for large $\hbar$, analytic solutions can be obtained for the time dependent quantum states for periodic chains and for open chains with absorbing boundary conditions. Steady state solutions and the properties of the relaxation to a steady state for a uniform QMB chain in contact with ``particle'' reservoirs can also be described analytically. The analytical results are consistent with, and confirmed by, results obtained from numerical methods. We report here results for the deep quantum regime (large $\hbar$) of the uniform QMB, as well as some results for the random QMB. We leave the moderate and small $\hbar$ results as well as further consideration of the other versions of the QMB for further publications.Comment: 17 pages, referee's and editor's comments addresse