Transfer of Brazilian Technologies to West Africa.

Brazil provided technical assistance to Cotton-4 (C-4) countries in West Africa, namely, Benin, Burkina Faso, Mali and Chad through a project that was implemented during 2009-13. The project was designed and implemented with the purpose of transferring environment-friendly cotton production technologies from Brazil to enhance yields and fibre quality in Africa. The Project was an initiative of the Government of Brazil through the Brazilian Cooperation Agency (ABC).Paper presented at the Technical Seminar on ?Opportunities and Challenges for Technology Transfer in Cotton? during the 76th Plenary Meeting of ICAC at Tashkent, Uzbekistan. October 22-27, 2017

Gathering Anonymous, Oblivious Robots on a Grid

We consider a swarm of $n$ autonomous mobile robots, distributed on a 2-dimensional grid. A basic task for such a swarm is the gathering process: All robots have to gather at one (not predefined) place. A common local model for extremely simple robots is the following: The robots do not have a common compass, only have a constant viewing radius, are autonomous and indistinguishable, can move at most a constant distance in each step, cannot communicate, are oblivious and do not have flags or states. The only gathering algorithm under this robot model, with known runtime bounds, needs $\mathcal{O}(n^2)$ rounds and works in the Euclidean plane. The underlying time model for the algorithm is the fully synchronous $\mathcal{FSYNC}$ model. On the other side, in the case of the 2-dimensional grid, the only known gathering algorithms for the same time and a similar local model additionally require a constant memory, states and "flags" to communicate these states to neighbors in viewing range. They gather in time $\mathcal{O}(n)$. In this paper we contribute the (to the best of our knowledge) first gathering algorithm on the grid that works under the same simple local model as the above mentioned Euclidean plane strategy, i.e., without memory (oblivious), "flags" and states. We prove its correctness and an $\mathcal{O}(n^2)$ time bound in the fully synchronous $\mathcal{FSYNC}$ time model. This time bound matches the time bound of the best known algorithm for the Euclidean plane mentioned above. We say gathering is done if all robots are located within a $2\times 2$ square, because in $\mathcal{FSYNC}$ such configurations cannot be solved

Tunneling mediated by conical waves in a 1D lattice

The nonlinear propagation of 3D wave-packets in a 1D Bragg-induced band-gap system, shows that tranverse effects (free space diffraction) affect the interplay of periodicity and nonlinearity, leading to the spontaneous formation of fast and slow conical localized waves. Such excitation corresponds to enhanced nonlinear transmission (tunneling) in the gap, with peculiar features which differ on the two edges of the band-gap, as dictated by the full dispersion relationship of the localized waves.Comment: 5 pages, 6 figure

Field quantization in inhomogeneous anisotropic dielectrics with spatio-temporal dispersion

A quantum damped-polariton model is constructed for an inhomogeneous anisotropic linear dielectric with arbitrary dispersion in space and time. The model Hamiltonian is completely diagonalized by determining the creation and annihilation operators for the fundamental polariton modes as specific linear combinations of the basic dynamical variables. Explicit expressions are derived for the time-dependent operators describing the electromagnetic field, the dielectric polarization and the noise term in the latter. It is shown how to identify bath variables that generate the dissipative dynamics of the medium.Comment: 24 page

Manejo de plantas daninhas na cultura do feijoeiro em plantio direto.

Principais espécies de plantas daninhas; Interferências das plantas daninhas; Métodos de manejo das plantas daninhas; Plantio direto: cobertura morta e cobertura viva; herbicidas; Manejo de herbicidas pré-plantio; Manejo cultural; Manejo de herbicidas em pré e pós emergência.bitstream/CNPAF/17135/1/circ_35.pd

A Textured Silicon Calorimetric Light Detector

We apply the standard photovoltaic technique of texturing to reduce the reflectivity of silicon cryogenic calorimetric light detectors. In the case of photons with random incidence angles, absorption is compatible with the increase in surface area. For the geometrically thin detectors studied, energy resolution from athermal phonons, dominated by position dependence, is proportional to the surface-to-volume ratio. With the CaWO4 scintillating crystal used as light source, the time constants of the calorimeter should be adapted to the relatively slow light-emission times.Comment: Submitted to Journal of Applied Physic

A construção da planta e o manejo de doenças do feijoeiro.

Observando todas as práticas culturais percebem-se o quanto se pode deixar de produzir quando acontece um equívoco no planejamento e construção da planta de feijão. Esta situação pode ser potencializada pelo ambiente, quando os equívocos interagem com compactação e estresse hídrico, excesso ou falta de água, que podem fugir ao controle local, como nos veranicos. Os sintomas de desconforto da planta de feijão já começam a aparecer no inicio da sua germinação. O manejo adequado da semeadora adubadora no ato do plantio é fundamental para uma distribuição uniforme das sementes e o seu posicionamento em relação ao fertilizante, seja realmente distribuídas nos lugares propostos na regulagem inicial da máquina

Human development and food (In)Security in Brazil: prioritisation of regions for policies targeting rice and bean production.

The objective of this study was to identify the main poverty areas in Brazil and check if they are important in growing rice and beans in order to be considered as priority areas for agricultural research and extension services