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

UAV GNSS position corrections based on IoT™ communication protocol

With the increase of devices connected to the Internet, currently known as Internet of Things (IoT), it is important to use algorithms in data transmissions to achieve optimal results for a given application.The paper main goal is to gather Global Navigation Satellite System (GNSS) positions at maximum rate possible, process them in a Post-processed Kinematics (PPK) environment, in order to perform GNSS corrections when compared to real earth GNSS coordinates. This method translates as micro-adjustments of the Unmanned Aerial Vehicle (UAV) traveled path, achieving centimeter-level accuracy associated with GNSS actual position. These GNSS positions are collected by the UAV GNSS receiver, and then sent to a gateway by using LoRaWAN™ communications protocol.Experimental results were included in the paper.info:eu-repo/semantics/acceptedVersio

Vertex Operators and Soliton Solutions of Affine Toda Model with U(2) Symmetry

The symmetry structure of non-abelian affine Toda model based on the coset $SL(3)/SL(2)\otimes U(1)$ is studied. It is shown that the model possess non-abelian Noether symmetry closing into a q-deformed $SL(2)\otimes U(1)$ algebra. Specific two vertex soliton solutions are constructed.Comment: 17 pages, latex, misprints corrected, version to appear in J.Phys

Radiative Corrections to the Aharonov-Bohm Scattering

We consider the scattering of relativistic electrons from a thin magnetic flux tube and perturbatively calculate the order $\alpha$, radiative correction, to the first order Born approximation. We show also that the second order Born amplitude vanishes, and obtain a finite inclusive cross section for the one-body scattering which incorporates soft photon bremsstrahlung effects. Moreover, we determine the radiatively corrected Aharonov-Bohm potential and, in particular, verify that an induced magnetic field is generated outside of the flux tube.Comment: 14 pages, revtex, 3 figure

Ultrasonic pulse technique for evaluation of mechanical damage in processed coffee beans.

The knowledge of the physical characteristics of the coffee bean allows the transition from the conventional storage model in bags to the silo storage, and as an indirect measure of the improvement and conservation of the quality of the stored grain. The elastic modulus allows comparisons on the strength of material. The variations of this occur due to its chemical composition, microstructures and material defects, being able to be used as indicator of the physical integrity of the grain. The ultrasonic pulse technique is an alternative to obtain the elastic modulus in a simple and non-destructive way. In this context, it was proposed the development of a non-destructive methodology that will perform the quality evaluation by determining the elastic modulus of the coffee beans. For this purpose, a reference silo was constructed, reproducing the storage conditions, and the elastic modulus values were determined. The values obtained by the Stress Wave Timer apparatus are between 2.54 and 4.23 MPa, with a maximum load of 8.32 kN, and a calculated vertical pressure of 1,526 kPa. To evaluate the impact of the storage conditions and the loads applied during the non-destructive test, laboratory tests applied in seeds were performed, and the tetrazolium test was the only one able to differentiate the samples. It was concluded that Stress Wave Timer was able to determine the elastic modulus values for the coffee bean mass and could be used as an indicative of the quality.Título em português: Técnica de pulso ultrassônico para avaliação de danos mecânicos em grãos de café beneficiados

ACTH-dependent Cushing's syndrome: a revision of 43 cases

AIM: To evaluate the characteristics and outcomes of the patients diagnosed as ACTH-dependent Cushing syndrome, registered in the department. MATERIAL AND METHODS: We reviewed the files of forty-three patients followed from 1974 to 2002. RESULTS: A progressive rise in the number of patients diagnosed was found, being 80% females. Clinical suspicion was based mostly on the typical fat distribution; hirsutism and amenorrhoea were important in women. The more reliable diagnostic tests were: 11 pm cortisol, day curve of ACTH and cortisol, and dexamethasone suppression tests. The ACTH response to CRH during inferior petrosal sinus sampling permitted the diagnosis of ectopic source. In thirty-seven patients a pituitary adenoma was diagnosed. The three patients diagnosed before 1985 went for bilateral adrenalectomy (Nelson's syndrome in two); the others were submitted to transsphenoidal pituitary adenomectomy, obtaining remission in twenty six at the first operation and in two others at the second. Three patients had a recidive. Of the six patients with persistent disease (all treated with metyrapone or ketoconazole), three were submitted to radiotherapy, two to bilateral adrenalectomy, and one was waiting for surgery. Four patients had a bronchial carcinoid, successfully removed in three. One patient was lost to follow-up and another was still being evaluated. CONCLUSIONS: We found a positive evolution in the capacity to diagnose and treat these patients. Neurosurgical ability to achieve remission was 80% in the operated cases. More effective technical methods and drugs, as well as a multidisciplinary and dedicated medical team, lead to long lasting remissions in most of the patients

Modelo bioeconômico para avaliações ex-ante de investimentos e planejamento forrageiro em sistemas tradicionais de produção de bovinos de corte no cerrado.

A baixa rentabilidade da produção de bovinos de corte em pastagens plantadas com inadequado manejo e a falta de planejamento quanto a investimentos, capital de giro e manejo de forragens, envolve questões cruciais do negócio de propriedades rurais com tal atividade no bioma Cerrado. Para tratar tais questões construiu-se uma modelo matemático de otimização visando maximizar a receita líquida no final do período de planeamento de 8 anos com fluxo de caixa mensal e uma alocação otima de recursos. O modelo conceitualizado, formulado, testado e avaliado, visou a obtenção de uma ferramenta de planejamento forrageiro e análise de investimentos em renovação de pastagens e compra de animais. O modelo representa o comportamento dinâmico de processos bioeconomicos de fazendas de gado de corte localizadas em fronteiras no Cerrado, com opções para criação e engorda. A propriedade projetada, foi avaliada em 2 milhões de reais. Capital de giro inicial foi de R$300.000,00, e três políticas de crédito foram consideradas. A fazenda tem 800 hectares, dos quais 600 são ocupados com Brachiaria brizantha. No modelo, três categorias de pastagens são consideradas, e os animais são divididos em classes, a cada trimestre. Várias estratégias de gestão do rebanho e de investimentos são consideradas. A dinâmica do rebanho depende da disponibilidade de capital, o tempo de pastejo e as taxas de mortalidade de cada classe de animal. Usando macros do Excel, arquivos em formato MPS são gerados para diferentes "solvers". Assim, a ferramenta foi construída e implementada para subsidiar o planejamento de fazendas de bovinos de corte. Um plano bioeconômico foi projetado com uma receita líquida de R$ 253,528.55 no final de oito anos e uma taxa interna de retorno anual de 2,3%

Análise do comportamento in vitro de explantes foliares de pequizeiro (Caryocar brasiliense camb.) através de RAPD.

xEdição de resumos do 7º Congresso Brasileiro de Fisiologia Vegetal, Brasília, 1999

Einstein gravity as a 3D conformally invariant theory

We give an alternative description of the physical content of general relativity that does not require a Lorentz invariant spacetime. Instead, we find that gravity admits a dual description in terms of a theory where local size is irrelevant. The dual theory is invariant under foliation preserving 3-diffeomorphisms and 3D conformal transformations that preserve the 3-volume (for the spatially compact case). Locally, this symmetry is identical to that of Horava-Lifshitz gravity in the high energy limit but our theory is equivalent to Einstein gravity. Specifically, we find that the solutions of general relativity, in a gauge where the spatial hypersurfaces have constant mean extrinsic curvature, can be mapped to solutions of a particular gauge fixing of the dual theory. Moreover, this duality is not accidental. We provide a general geometric picture for our procedure that allows us to trade foliation invariance for conformal invariance. The dual theory provides a new proposal for the theory space of quantum gravity.Comment: 27 pages. Published version (minor changes and corrections