Plastic Deformation of 2D Crumpled Wires

When a single long piece of elastic wire is injected trough channels into a confining two-dimensional cavity, a complex structure of hierarchical loops is formed. In the limit of maximum packing density, these structures are described by several scaling laws. In this paper it is investigated this packing process but using plastic wires which give origin to completely irreversible structures of different morphology. In particular, it is studied experimentally the plastic deformation from circular to oblate configurations of crumpled wires, obtained by the application of an axial strain. Among other things, it is shown that in spite of plasticity, irreversibility, and very large deformations, scaling is still observed.Comment: 5 pages, 6 figure

Evading the Few TeV Perturbative Limit in 3-3-1 Models

Some versions of the electroweak SU(3)_L\otimesU(1)_X models cannot be treated within perturbation theory at energies of few TeV. An extended version for these models is proposed which is perturbative even at TeV scale posing no threatening inconsistency for test at future colliders. The extension presented here needs the addition of three octets of vector leptons, which leave three new leptonic isotriplets in the SU(2)_L\otimesU(1)_Y subgroup. With this representation content the running of the electroweak mixing angle, $\theta_W (\mu)$, is such that $\sin^2\theta_W(\mu)$ decreases with the increase of the energy scale $\mu$, when only the light states of the Standard Model group are considered. The neutral exotic gauge boson $Z^\prime$ marks then a new symmetry frontier.Comment: 15 pages, 2 figures, minor correction

Curso sobre o uso de técnicas de manejo e cultivo orgânico do solo em pequenas propriedades.

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Alterações em características químicas de amostras de compostos de bagaço de coco-verde resultantes do método de estocagem.

Para fins de pesquisa científica, por vezes o armazenamento de amostras de composto orgânico se faz necessária. Para tanto, o conhecimento da eficiência do método de estocagem utilizado, quanto à preservação das características iniciais da amostra, é imprescindível. O presente trabalho teve por objetivo avaliar os efeitos de duas formas de estocagem, sobre suas características químicas originais de amostras de compostos de resíduos agroindustriais do coco-verde estocadas há seis anos. Os compostos utilizados foram obtidos a partir da mistura de bagaço de coco-verde com torta de filtro, esterco bovino e fosfato natural de Gafsa, umedecidas com soluções com concentrações crescentes de vinhaça (0, 50 e 75%). As amostras foram coletadas após 131 dias de compostagem e analisadas após seis anos de armazenamento em potes herméticos (secas a 65ºC) ou sob congelamento em freezer (a -20ºC). Foram determinadas o pH em CaCl2, carbono orgânico (CO), nitrogênio total, relação C:N e teor de cinzas das amostras. Os métodos de estocagem distintamente influenciaram as variáveis consideradas, embora não tenham mostrado efeito sobre o pH. Significativos efeitos foram observados sobre os teores de carbono orgânico erelação C:N e, em menor grau, sobre os de nitrogênio total e cinzas. Em amostras conservadas por seis anos, as duas formas de estocagem podem produzir resultados os quais sugerem a maior ou menor maturidade dos compostos (respectivamente, para amostras secas e congeladas) que aquela observada por ocasião da coleta das amostras. Os resultados deste estudo revelam a necessidade da avaliação temporal da eficiência dos métodos de forma a evitar os problemas detectados decorrentes da estocagem prolongada de amostras de composto orgânico

Structural properties of crumpled cream layers

The cream layer is a complex heterogeneous material of biological origin which forms spontaneously at the air-milk interface. Here, it is studied the crumpling of a single cream layer packing under its own weight at room temperature in three-dimensional space. The structure obtained in these circumstances has low volume fraction and anomalous fractal dimensions. Direct means and noninvasive NMR imaging technique are used to investigate the internal and external structure of these systems.Comment: 9 pages, 4 figures, accepted in J. Phys. D: Appl. Phy

The use of data envelopment analysis in agriculture in the presence of interval data.

This paper uses Data Envelopment Analysis (DEA) models to measure the efficiency of some agricultural producers from the Holambra district (São Paulo - Brazil). The total area of each property is one of the variables of the model, presenting two possible values: the value declared by the producer and the value measured using IKONOS II satellite images. This variable presents uncertainty in its measurement and can be represented as interval data. The efficiency frontier is constructed considering the limits of uncertainty (interval limits), that is, the smallest and greatest possible values to be assumed for the imprecise variable. In this way, a region is constructed in relation to which the DMUs have a certain membership degree. The theoretical model, called interval DEA model, is presented, as well as its application to the case of the evaluation of the efficiency of the agricultural producers of Holambra

Características fenológicas de cana-de-açúcar adubada com fertilizantes minerais adicionados de substâncias húmicas.

O presente trabalho teve por objetivo avaliar o efeito de fertilizantes minerais adicionados de substâncias húmicas sobre características fenológicas da cana de açúcar. Para tanto, foi realizado cultivo de inverno das variedades de cana RB867515 e RB92579, as quais foram adubadas com diferentes fertilizantes minerais com adição de substâncias húmicas - SH (MAP + SH, Gáfisa + SH, silicato de Ca e Mg + SH), nas condições edafo-climáticas do Estado de Alagoas. Aos 225 dias foram realizadas medições de parâmetros fenológicos da planta e obtidos o índice de área foliar (IAF), toneladas de cana por hectare (TCH) e número de colmo por metro linear (NCM). Verificou-se que a RB 867515 apresentou maior IAF e TCH enquanto a variedade RB92579 apresentou maior NCM; a adubação com MAP foi superior às demais para a variável TCH; a variedade RB92579 apresentou maior TCH e NCM e a variedade RB867515 maior TCH, quando adubadas com MAP adicionado de SH

The Acquisition of Variable Coda (r) in the Speech Community of Rio de Janeiro

This paper addresses the emergence of complex syllables with coda consonant (r) in the acquisition of Brazilian Portuguese in the speech community of Rio de Janeiro. Acquisition of words containing complex syllabic types implies the diminishment or abandonment of the CV pattern, but what happen when the competing variable forms alternate different syllable shapes? Since variants are competing forms of the same word, in some cases, they also reflect competing phonological patterns and sociophonetic variation plays a role in abstracting mental representation. Studies about the speech community showed that the coda is variably realized alternating a phonetic velar/glottal variant with its absence and that internal codas are much more realized than final ones (Callou, 1987; Votre, 1978). There is no stigma related to the zero variant in final coda (noun and verbs). The study is based on a cross-sectional sample of 11 typically-developing children (from high and low middle class) distributed in age levels but not in relation to gender or class. The age grading ranges from 2;1 to 5;0. The analysis showed different distributions of frequency of variants as a reflex of the structured variation observed in the speech community. The results reveal that (r) is almost categorically absent in final verbs in all age levels, which can be taken as evidence that children are developing the CV pattern as the main representation of infinitives. Children’s behavior for medial codas is more consistent with a CV(r) pattern as the central representation than word final coda in all ages. The results obtained in this study for final verb coda is consistent with a final stage of a change in the direction of the loss of the infinitive morpheme in the speech community