Generalising the logistic map through the qq-product

We investigate a generalisation of the logistic map as $x_{n+1}=1-ax_{n}\otimes_{q_{map}} x_{n}$ ($-1 \le x_{n} \le 1$, $0<a\le2$) where $\otimes_q$ stands for a generalisation of the ordinary product, known as $q$-product [Borges, E.P. Physica A {\bf 340}, 95 (2004)]. The usual product, and consequently the usual logistic map, is recovered in the limit $q\to 1$, The tent map is also a particular case for $q_{map}\to\infty$. The generalisation of this (and others) algebraic operator has been widely used within nonextensive statistical mechanics context (see C. Tsallis, {\em Introduction to Nonextensive Statistical Mechanics}, Springer, NY, 2009). We focus the analysis for $q_{map}>1$ at the edge of chaos, particularly at the first critical point $a_c$, that depends on the value of $q_{map}$. Bifurcation diagrams, sensitivity to initial conditions, fractal dimension and rate of entropy growth are evaluated at $a_c(q_{map})$, and connections with nonextensive statistical mechanics are explored.Comment: 12 pages, 23 figures, Dynamics Days South America. To be published in Journal of Physics: Conference Series (JPCS - IOP

Study of the fracture process of Al Hoceima earthquake (24/02/2004, Mw=6.2) from regional and teleseismic data.

We studied the source time function (STF) and rupture process of the 2004 Alhoceima, Morocco earthquake of Mw = 6.2 using teleseismic and regional broad-band data. From regional broad-band data, STF function was determined using three large after- shocks as empirical Green functions. We inverted of body wave forms at teleseismic distances using an extended source model with rupture velocity between 2.5-3.0 km and using as preliminary orientation the fault plane solution derived from 126 P-wave polarities. Results show a complex bilateral rupture formed by four shallow subevents (2-8 km) with a maximum seismic moment release during the first seconds (more than 80% of a total of 1.8x1018 Nm) and time duration of 8-10 s. The focal mechanism shows a strike slip motion with a normal component. Nodal planes strike on NNE- SSW and WNW-ESE direction with horizontal pressure axes in NNW-SSE direction. The rupture propagated mainly towards the North. This propagation is in agreement with the damages caused in the epicentral region. The larger aftershocks have been relocated using a master event method. Comparisson of these results with those ob- tained for the 1994 earthquake shown similar behaviour: complex rupture process and, apparently, no relation of the 1994 nor the 2004 shocks with the Nekor fault, the most important geological feature in the area. The stress pattern derived from focal mech- anisms of 1994 and 2004 are in agreement with the regional stress pattern, horizontal compression in NNW-SSE and horizontal extension in E-W direction in the Alboran Sea

Optimized Multimode Interference Fiber Based Refractometer in A Reflective Interrogation Scheme

A fiber based refractometer in a reflective interrogation scheme is investigated and optimized. A thin gold film was deposited on the tip of a coreless fiber section, which is spliced with a single mode fiber. The coreless fiber is a multimode waveguide, and the observed effects are due to multimode interference. To investigate and optimize the structure, the multimode part of the sensor is built with 3 different lengths: 58 mm, 29 mm and 17 mm. We use a broadband light source ranging from 1475 nm to 1650 nm and we test the sensors with liquids of varying refractive indices, from 1.333 to 1.438. Our results show that for a fixed wavelength, the sensor sensitivity is independent of the multimode fiber length, but we observed a sensitivity increase of approximately 0.7 nm/RIU for a one-nanometer increase in wavelength

Alterations in brain connectivity due to plasticity and synaptic delay

Brain plasticity refers to brain's ability to change neuronal connections, as a result of environmental stimuli, new experiences, or damage. In this work, we study the effects of the synaptic delay on both the coupling strengths and synchronisation in a neuronal network with synaptic plasticity. We build a network of Hodgkin-Huxley neurons, where the plasticity is given by the Hebbian rules. We verify that without time delay the excitatory synapses became stronger from the high frequency to low frequency neurons and the inhibitory synapses increases in the opposite way, when the delay is increased the network presents a non-trivial topology. Regarding the synchronisation, only for small values of the synaptic delay this phenomenon is observed

Recomendação de boro para o maracujazeiro amarelo em solo de Tabuleiro Costeiro.

Nos estados que mais produzem maracujá no Brasil: Bahia, Sergipe, Espírito Santo e Rio de Janeiro, o maracujazeiro é cultivado em solos de Tabuleiros Costeiros. No Estado da Bahia cultiva- se aproximadamente 45% da produção nacional (322.755 toneladas) em 23.227 hectares, cuja produtividade média é inferior à nacional. Em 6.845 hectares de solos de Tabuleiros Costeiros do Estado da Bahia são produzidos 76.355 toneladas de maracujá, o que representa 24% da produção do Estado e 29% da área cultivada (IBGE, 2009). Os solos de Tabuleiros Costeiros são altamente intemperizados, com baixos teores de matéria orgânica, baixa capacidade de armazenamento de água e altos teores de ferro e alumínio, favorecenda deficiência de boro nas plantas de maracujá (BORGES et al., 2010).bitstream/item/55052/1/ComunicadoTecnico-149.pdfPublicação eletrônica

Produção de composto orgânico em pequenas propriedades.

Composto orgânico é um adubo natural, preparado com produtos de origem vegetal e animal, que contém nutrientes para as plantas, em diferentes quantidades. É formado por matéria orgânica, que é um fator de grande importância para tornar a terra mais adequada para o desenvolvimento das plantas.bitstream/item/106266/1/Produto-Foco-organico-3.pdfOnline

Recomendação de zinco para o maracujazeiro amarelo em solo de Tabuleiro Costeiro do Estado da Bahia.

A unidade de paisagem dos Tabuleiros Costeiros ocupa 5,92% da área da Região Nordeste, sendo que cerca de 40% dessa unidade localiza-se no Estado da Bahia (SILVA et al., 1993). O maracujazeiro é cultivado nos Tabuleiros Costeiros nos Estados da Bahia, Sergipe, Espírito Santo e Rio de Janeiro, onde predominam os Latossolos Amarelos, que são profundos, porém distrocoesos. Em 2009, a produção do Estado da Bahia foi de 322.755 toneladas de frutos em uma área de 23.227 hectares (13,9 t ha-1) (IBGE, 2009). Desse total, 76.355 toneladas foram produzidas em 6.845 hectares, em solos localizados nos Tabuleiros Costeiros, com produtividade de 11,2 t ha-1. O Estado da Bahia participa com 61% da produção da Região Nordeste, o que equivale a 45% do total nacional (IBGE, 2009).bitstream/item/55059/1/ComunicadoTecnico-148-1.pdf(Embrapa Mandioca e Fruticultura. Comunicado técnico, 148)