Comportamento de mudas de nim à salinidade da água em solo não salino com biofertilizante

An experiment was carried out in greenhouse during the period January to April 2010, at Center of Agricultural Sciences of the Federal University of Paraiba, in Areia, Paraiba State, Brazil, in order to evaluate the effects of saline water and bovine biofertilizer on the seedling growth of Indian neem. The substrate was material of a non-saline soil collected in depth of 0-20 cm. The treatments were arranged in a completely randomized design using a 5 x 2 factorial, referring to salinity levels of irrigation water of 0.5, 1.0, 2.0, 3.0 and 4.0 dS m(-1), with and without bovine biofertilizer applied to the soil only once after dilution with water (1: 1), a day before sowing, in volume corresponding to 10% of the substrate. At 86 days after emergence of seedlings the plant growth in height and principal root length, diameter of stem and root, leaf number and dry mass of roots and shoots of plants were evaluated. The salinity of irrigation water increased the salinity levels in the substrate inhibiting the growth in height, stem diameter, leaf emission by plants, diameter and length of principal root and the dry matter production of roots and aerial parts (leaves + stem) of neem, but with less pronounced decrease in plants under the treatments with bovine biofertilizer.

Nitrogênio e potássio via fertirrigação e adubação convencional-estado nutricional das bananeiras e produção de frutos

Realizou-se um experimento em Pindorama (SP) com o objetivo de avaliar os efeitos da fertirrigação e da adubação convencional com N e K, em bananeiras, durante dois ciclos de produção. Foram avaliados crescimento, estado nutricional e produção de frutos. A adubação causou redução do ciclo de produção. Os teores foliares de N e K foram influenciados pela adubação convencional e pela fertirrigação. Nos dois ciclos de cultivo, a produção de frutos variou em função dos tratamentos. A produção de frutos (t ha¹ ano¹) obtida com a aplicação de 80% da dose de N e de K via fertirrigação foi equivalente àquela com 100% da dose via adubação convencional.

Variação sazonal de micronutrientes em folhas de aceroleira (Malpighia emarginata DC.)

Os teores de micronutrientes nas folhas necessários para obter boa produtividade e qualidade de frutos de aceroleira (Malpighia emarginata DC.) e sua variação sazonal são pouco conhecidas. Para melhor entendimento da dinâmica de absorção de nutrientes e o desenvolvimento dessa frutífera avaliaram-se teores foliares de Cu, Fe, Mn e Zn, em seis progênies de aceroleira no período de dezembro de 1999 a outubro de 2000. O estudo foi conduzido na Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) Agroindústria Tropical, em Pacajus, e envolveu 6 progênies (P52, P66, P78, P91, P93 e P97) e 6 épocas de amostragem das folhas (dezembro, fevereiro, abril, junho, agosto e outubro de 2000). A variação sazonal foi confirmada para os teores de Cu, Fe, Mn e Zn nas folhas, enquanto o Zn não sofreu alteração significativa nas progênies consideradas pela pesquisa. Os teores de Cu foram superiores em fevereiro, e os de Fe e Mn em agosto. As progênies apresentaram habilidade diferenciada na manutenção das concentrações de Cu, Mn e Zn nas folhas. A melhor época para amostragem de folhas e diagnóstico do estado nutricional foi em outubro, início do florescimento das aceroleiras, quando os teores de Cu, Fe, Mn e Zn devem ser superiores a 3, 125, 80 e 15 mg/kg.

Redistribuição de nutrientes em folhas de pinhão-manso entre estádios fenológicos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fotossíntese, reservas orgânicas e rebrota do capim-mombaça (Panicum maximum Jacq.) sob diferentes intensidades de desfolha do perfilho principal

Buscando-se avaliar morfofisiologicamente a rebrota do capim-mombaça, quatro desfolhas foram impostas ao perfilho principal, sendo estudado o comportamento da planta em termos da taxa de expansão da área foliar, crescimento do sistema radicular, nível de carboidratos totais não estruturais (CTNE) da raiz e do colmo, taxa de crescimento relativo (TCR), taxa de assimilação líquida (TAL) e razão de área foliar (RAF) às idades de 2, 5, 9 e 16 dias após as desfolhas, bem como da taxa fotossintética máxima às idades de 2, 6 e 13 dias das folhas remanescentes à desfolha. As desfolhas foram as seguintes: remoção de todas as lâminas foliares (desfolha total), a remoção da lâmina da folha adulta mais jovem (desfolha superior), a remoção das lâminas das duas folhas adultas mais velhas (desfolha inferior) e controle (sem desfolha), juntamente com o corte dos demais perfilhos, realizado a 8 cm do solo. Foram observadas cinco repetições por tratamento, segundo o delineamento inteiramente casualizado. As folhas adultas não diferiram quanto às taxas fotossintéticas máximas, que exibiram aumento nos primeiros dias após a desfolha, e queda aos 13 dias. A desfolha reduziu os teores de CTNE da base do colmo, principalmente nas plantas sob desfolha total. Comprometimento do crescimento do sistema radicular e do teor de CTNE das raízes foi observado nas plantas sob desfolha total, que também tiveram sua TCR reduzida nos primeiros dias de rebrotação. Entretanto, o aumento na RAF possibilitou a estas plantas recuperação da TCR e alta taxa de expansão da área foliar, igualando a área foliar das demais plantas aos 16 dias de rebrota.

Massa de forragem, composição morfológica e química de capim-tanzânia sob diferentes dias de descanso e altura de resíduo pós-pastejo

The experiment was conducted at UNESP/FCAV, Jaboticabal, SP, with the objective of evaluating the influence of the rest period and height of the residue post-grazing on the dry matter mass, morphologic composition and on the chemical composition of the Tanzania-grass pre-grazing condition, under rotational grazing. The treatments consisted of the combination of two rest periods (25 and 35 days) and two residue height post-grazing (30 and 50 cm), as a complete randomized design in factorial arrangement 2 x 2, with three replications, with the grazing cycles considered as sub plots. The herbage mass of stem, leaves, dead material and the leaf: stem ratio were significantly influenced (P<0.05) by the grazing cycles. The percentage of CP in the leaf and stem and the NDF in the stem, leaf and whole plant were influenced positively (P<0.05) by the grazing cycles. It was observed that the short rest periods associated with the smallest residue height post-grazing presented the best results in terms of herbage mass and chemical characteristics of the herbage.

Análise e síntese de antenas e superfícies seletivas de frequência utilizando computação evolucionária e inteligência de enxames

The frequency selective surfaces, or FSS (Frequency Selective Surfaces), are structures consisting of periodic arrays of conductive elements, called patches, which are usually very thin and they are printed on dielectric layers, or by openings perforated on very thin metallic surfaces, for applications in bands of microwave and millimeter waves. These structures are often used in aircraft, missiles, satellites, radomes, antennae reflector, high gain antennas and microwave ovens, for example. The use of these structures has as main objective filter frequency bands that can be broadcast or rejection, depending on the specificity of the required application. In turn, the modern communication systems such as GSM (Global System for Mobile Communications), RFID (Radio Frequency Identification), Bluetooth, Wi-Fi and WiMAX, whose services are highly demanded by society, have required the development of antennas having, as its main features, and low cost profile, and reduced dimensions and weight. In this context, the microstrip antenna is presented as an excellent choice for communications systems today, because (in addition to meeting the requirements mentioned intrinsically) planar structures are easy to manufacture and integration with other components in microwave circuits. Consequently, the analysis and synthesis of these devices mainly, due to the high possibility of shapes, size and frequency of its elements has been carried out by full-wave models, such as the finite element method, the method of moments and finite difference time domain. However, these methods require an accurate despite great computational effort. In this context, computational intelligence (CI) has been used successfully in the design and optimization of microwave planar structures, as an auxiliary tool and very appropriate, given the complexity of the geometry of the antennas and the FSS considered. The computational intelligence is inspired by natural phenomena such as learning, perception and decision, using techniques such as artificial neural networks, fuzzy logic, fractal geometry and evolutionary computation. This work makes a study of application of computational intelligence using meta-heuristics such as genetic algorithms and swarm intelligence optimization of antennas and frequency selective surfaces. Genetic algorithms are computational search methods based on the theory of natural selection proposed by Darwin and genetics used to solve complex problems, eg, problems where the search space grows with the size of the problem. The particle swarm optimization characteristics including the use of intelligence collectively being applied to optimization problems in many areas of research. The main objective of this work is the use of computational intelligence, the analysis and synthesis of antennas and FSS. We considered the structures of a microstrip planar monopole, ring type, and a cross-dipole FSS. We developed algorithms and optimization results obtained for optimized geometries of antennas and FSS considered. To validate results were designed, constructed and measured several prototypes. The measured results showed excellent agreement with the simulated. Moreover, the results obtained in this study were compared to those simulated using a commercial software has been also observed an excellent agreement. Specifically, the efficiency of techniques used were CI evidenced by simulated and measured, aiming at optimizing the bandwidth of an antenna for wideband operation or UWB (Ultra Wideband), using a genetic algorithm and optimizing the bandwidth, by specifying the length of the air gap between two frequency selective surfaces, using an optimization algorithm particle swarm

Análise e projeto de superfícies seletivas de frequência com elementos pré-fractais para aplicações em comunicações indoor

In this thesis, a frequency selective surface (FSS) consists of a two-dimensional periodic structure mounted on a dielectric substrate, which is capable of selecting signals in one or more frequency bands of interest. In search of better performance, more compact dimensions, low cost manufacturing, among other characteristics, these periodic structures have been continually optimized over time. Due to its spectral characteristics, which are similar to band-stop or band-pass filters, the FSSs have been studied and used in several applications for more than four decades. The design of an FSS with a periodic structure composed by pre-fractal elements facilitates the tuning of these spatial filters and the adjustment of its electromagnetic parameters, enabling a compact design which generally has a stable frequency response and superior performance relative to its euclidean counterpart. The unique properties of geometric fractals have shown to be useful, mainly in the production of antennas and frequency selective surfaces, enabling innovative solutions and commercial applications in microwave range. In recent applications, the FSSs modify the indoor propagation environments (emerging concept called wireless building ). In this context, the use of pre-fractal elements has also shown promising results, allowing a more effective filtering of more than one frequency band with a single-layer structure. This thesis approaches the design of FSSs using pre-fractal elements based on Vicsek, Peano and teragons geometries, which act as band-stop spatial filters. The transmission properties of the periodic surfaces are analyzed to design compact and efficient devices with stable frequency responses, applicable to microwave frequency range and suitable for use in indoor communications. The results are discussed in terms of the electromagnetic effect resulting from the variation of parameters such as: fractal iteration number (or fractal level), scale factor, fractal dimension and periodicity of FSS, according the pre-fractal element applied on the surface. The analysis of the fractal dimension s influence on the resonant properties of a FSS is a new contribution in relation to researches about microwave devices that use fractal geometry. Due to its own characteristics and the geometric shape of the Peano pre-fractal elements, the reconfiguration possibility of these structures is also investigated and discussed. This thesis also approaches, the construction of efficient selective filters with new configurations of teragons pre-fractal patches, proposed to control the WLAN coverage in indoor environments by rejecting the signals in the bands of 2.4~2.5 GHz (IEEE 802.11 b) and 5.0~6.0 GHz (IEEE 802.11a). The FSSs are initially analyzed through simulations performed by commercial software s: Ansoft DesignerTM and HFSSTM. The fractal design methodology is validated by experimental characterization of the built prototypes, using alternatively, different measurement setups, with commercial horn antennas and microstrip monopoles fabricated for low cost measurements

Antenas e superfícies seletivas de freqüência reconfiguráveis para sistemas de comunicação sem fio

This work aims to present how the reconfigurable microstrip antennas and frequency selective surfaces can be used to operate at communication systems that require changing their operation frequency according to system requirements or environmental conditions. The main purpose is to present a reconfigurable circular microstrip antenna using a parasitic ring and a reconfigurable dipole frequency selective surface. Thereupon there are shown fundamental topics like microstrip antennas, PIN diodes and the fundamental theory of reconfigurable antennas and frequency selective surfaces. There are shown the simulations and measurements of the fabricated prototypes and it is done an analysis of some parameters like the bandwidth and radiation pattern, for the antennas, and the transmission characteristics, for the frequency selective surface. Copper strips were used in place of the diodes for proof of the reconfigurability concept

Estudo avaliativo de um algoritmo genético auto-organizável e multiobjetivo utilizando aprendizado de máquina para aplicações de telecomunicações

This paper presents an evaluative study about the effects of using a machine learning technique on the main features of a self-organizing and multiobjective genetic algorithm (GA). A typical GA can be seen as a search technique which is usually applied in problems involving no polynomial complexity. Originally, these algorithms were designed to create methods that seek acceptable solutions to problems where the global optimum is inaccessible or difficult to obtain. At first, the GAs considered only one evaluation function and a single objective optimization. Today, however, implementations that consider several optimization objectives simultaneously (multiobjective algorithms) are common, besides allowing the change of many components of the algorithm dynamically (self-organizing algorithms). At the same time, they are also common combinations of GAs with machine learning techniques to improve some of its characteristics of performance and use. In this work, a GA with a machine learning technique was analyzed and applied in a antenna design. We used a variant of bicubic interpolation technique, called 2D Spline, as machine learning technique to estimate the behavior of a dynamic fitness function, based on the knowledge obtained from a set of laboratory experiments. This fitness function is also called evaluation function and, it is responsible for determining the fitness degree of a candidate solution (individual), in relation to others in the same population. The algorithm can be applied in many areas, including in the field of telecommunications, as projects of antennas and frequency selective surfaces. In this particular work, the presented algorithm was developed to optimize the design of a microstrip antenna, usually used in wireless communication systems for application in Ultra-Wideband (UWB). The algorithm allowed the optimization of two variables of geometry antenna - the length (Ls) and width (Ws) a slit in the ground plane with respect to three objectives: radiated signal bandwidth, return loss and central frequency deviation. These two dimensions (Ws and Ls) are used as variables in three different interpolation functions, one Spline for each optimization objective, to compose a multiobjective and aggregate fitness function. The final result proposed by the algorithm was compared with the simulation program result and the measured result of a physical prototype of the antenna built in the laboratory. In the present study, the algorithm was analyzed with respect to their success degree in relation to four important characteristics of a self-organizing multiobjective GA: performance, flexibility, scalability and accuracy. At the end of the study, it was observed a time increase in algorithm execution in comparison to a common GA, due to the time required for the machine learning process. On the plus side, we notice a sensitive gain with respect to flexibility and accuracy of results, and a prosperous path that indicates directions to the algorithm to allow the optimization problems with "η" variables

Caracterização de superfícies seletivas de freqüência e de antenas fractais para aplicações em redes sem fio

This work aims to investigate the behavior of fractal elements in planar microstrip structures. In particular, microstrip antennas and frequency selective surfaces (FSSs) had changed its conventional elements to fractal shapes. For microstrip antennas, was used as the radiating element of Minkowski fractal. The feeding method used was microstrip line. Some prototypes were built and the analysis revealed the possibility of miniaturization of structures, besides the multiband behavior, provided by the fractal element. In particular, the Minkowski fractal antenna level 3 was used to exploit the multiband feature, enabling simultaneous operation of two commercial tracks (Wi-Fi and WiMAX) regulated by ANATEL. After, we investigated the effect of switches that have been placed on the at the pre-fractal edges of radiating element. For the FSSs, the fractal used to elements of FSSs was Dürer s pentagon. Some prototypes were built and measured. The results showed a multiband behavior of the structure provided by fractal geometry. Then, a parametric analysis allowed the analysis of the variation of periodicity on the electromagnetic behavior of FSS, and its bandwidth and quality factor. For numerical and experimental characterization of the structures discussed was used, respectively, the commercial software Ansoft DesignerTM and a vector network analyzer, Agilent N5230A model

Caracterização de circuitos planares de micro-ondas pelo método iterativo das ondas

The planar circuits are structures that increasingly attracting the attention of researchers, due the good performance and capacity to integrate with other devices, in the prototyping of systems for transmitting and receiving signals in the microwave range. In this context, the study and development of new techniques for analysis of these devices have significantly contributed in the design of structures with excellent performance and high reliability. In this work, the full-wave method based on the concept of electromagnetic waves and the principle of reflection and transmission of waves at an interface, Wave Concept Iterative Procedure (WCIP), or iterative method of waves is described as a tool with high precision study microwave planar circuits. The proposed method is applied to the characterization of planar filters, microstrip antennas and frequency selective surfaces. Prototype devices were built and the experimental results confirmed the proposed mathematical model. The results were also compared with simulated results by Ansoft HFSS, observing a good agreement between them.

Desenvolvimento de grãos e produção de fitomassa do girassol em função de adubações boratadas

Sunflower crop is a good option to no-tillage system; however, it is sensible to low B availability, what is common in tropical soils. The objective of this study was to evaluate the crop development, grain yield and grain size as affected by B fertilizer doses applied in the sowing and by leaf application. The experiment was conducted in controlled conditions, with four Borax doses (0; 1; 2 e 3 kg B ha(-1)) in the sowing interacting with four Boric Acid doses (0; 0,5; 1 e 2 kg B ha(-1)) by leaf application. The plants were managed until grain physiological maturity, when stems, leaves and capitula were sampled, besides the counting and weighing of two grain classes separated by size. The B fertilizer applied in the sowing lines increased total dry matter phytomass and grain yield. However, when interacting with high doses of B by leaf application, these values decreased. Grain size was increased with leaf fertilization, when B was not applied in the soil or with only 1 kg B ha(-1) in the sowing line. on the other hand, when B was applied from 2 to 3 kg ha(-1) in the crop sowing, high doses of leaf fertilizer affected grain filling.

Efeito da deriva de Glyphosate sobre algumas características fisiológicas em plantas de eucalipto

This work aims to evaluate the effects of a simulated drift of glyphosate at different doses on some physiological characteristics of Eucalyptus grandis. A completely randomized design with five replications was used, where each pot contained an eucalyptus plant and was considered as one repetition. The plants received doses of glyphosate corresponding to 0, 30, 60, 90 and 120g.ha(-1), in the Scout (R) commercial formulation: The application was performed in three forms: leaves, stem and whole plant (leaf + stem). For foliar application, the stem was covered with plastic tape to avoid being hit by the solution, and leaves with a plastic bag when the stem was spayed. The application was performed by means of a steady spray gun equipped with four XR 11002 tips, with a pressure of 200Kpa and a volume of 2001 ha(-1). Stomatal conductance, transpiration and leaf temperature were measured at 7 days after application (DAA). The eucalypt plants receiving applications in leaves and whole plant showed, at the highest glyphosate dosis (120g.ha(-1)), a transpiration reduced by 22% and an 18% increase of stomatal resistance at 7 DAA. The lowest dose (30g-ha(-1)) applied to the whole plant caused a transpiration stimulation of 18%, and a leaf to air difference in temperature of -1.66 degrees C, while the difference between the highest and lowest dose used was 3.5 degrees C.

Desempenho mecânico de compósitos híbridos de fibras naturais e poliéster não saturado

With the objective to promote sustainable development, the fibres found in nature in abundance, which are biodegradable, of low cost in comparison to synthetic fibres are being used in the manufacture of composites. The mechanical behavior of the curauá and pineapple leaf fibre (PALF) composites in different proportions, 25% x 75% (P1), 50% x 50% (P2) e 75% x 25% (P3) were respectively studied, being initially treated with a 2% aqueous solution of sodium hydroxide. Mechanical analyses indicated that with respect to studies of traction, for the combination of P1 and P3, better results of 22.17 MPa and 16.98 MPa, were obtained respectively, which are higher than that of the combination P2. The results of the same pattern were obtained for analysis of bending resistance where P1 is 1.21% and P3 represents 0.96%. In the case of resistance to bending, best results were obtained for the combination P1 at 49.07 MPa. However, when Young's modulus values were calculated, the values were different to the pattern of the results of other tests, where the combination P2 with the value of 4.06 GPa is greater than the other combinations. This shows that the PALF had a greater influence in relation to curauá fibre. The analysis of the results generally shows that in combinations of two vegetable fibers of cellulosic origin, the fiber which shows higher percentage (75%) is the best option than to the composition of 50%/50%. In the meantime, according to the results obtained in this study, in the case where the application should withstand bending loads, the better composition would be 50%/50%