Five-dimensional null & time-like supersymmetric geometries

We show that there exist supersymmetric solutions of five-dimensional, pure, $\mathcal{N}=1$ Supergravity such that the norm of the supersymmetric Killing vector, built out of the Killing spinor, is a real not-everywhere analytic function such that all its derivatives vanish at a point where the Killing vector field becomes null. The norm of the Killing vector field then is not an analytic function on a neighborhood around this point. We explicitly construct such solutions by using a multi-center Gibbons-Hawking base. Although many of these solutions have infinite charges, we find explicit examples with finite charges that asymptote to $AdS_3\times S_2$ and discuss their physical interpretation.Comment: 19 pages, 4 figures, open-vanishing conclusion changed due to non-analiticity of the Killing vecto

Pasta-making properties of the new durum wheat variety biensur suitable for the northern mediterranean environment

Industrial pasta is commonly made from mixtures of semolina from different durum wheat varieties, and there is a very low market presence of mono-varietal pasta from local, short supply chains. In this work, dough rheological properties and pasta quality traits of the new durum wheat cv. Biensur, which has a high HMW/LMW-GS ratio, were evaluated with a view to developing short-chain, mono-varietal pasta production in NE Italy. Chemical and sensory analyses on short-cut pasta, viz. tubetti, made with semolina from cv. Biensur at two drying temperatures revealed that it has good technological characteristics and stability, excellent cooking and sensory properties, and is comparable to the high-quality commercial reference cv. Aureo. We conclude that Biensur provides farmers and traders with new market opportunities and offers improvements to the environmental and economic sustainability of the durum wheat chain

Scaling of excitations in dimerized and frustrated spin-1/2 chains

We study the finite-size behavior of the low-lying excitations of spin-1/2 Heisenberg chains with dimerization and next-to-nearest neighbors interaction, J_2. The numerical analysis, performed using density-matrix renormalization group, confirms previous exact diagonalization results, and shows that, for different values of the dimerization parameter \delta, the elementary triplet and singlet excitations present a clear scaling behavior in a wide range of \ell=L/\xi (where L is the length of the chain and \xi is the correlation length). At J_2=J_2c, where no logarithmic corrections are present, we compare the numerical results with finite-size predictions for the sine-Gordon model obtained using Luscher's theory. For small \delta we find a very good agreement for \ell > 4 or 7 depending on the excitation considered.Comment: 4 pages, 4 eps figures, RevTeX 4 class, same version as in PR

Modeling Daily Production of Aquatic Macrophytes from Irradiance Measurements: A Comparative Analysis

The importance of submerged aquatic macrophytes to coastal ecosystems has generated a need for knowledge of minimum light levels that will support the maintenance and restoration of healthy populations. Our goals were (1) to evaluate the sensitivity to natural, non-sinusoidal fluctuations in irradiance I of analytical integration techniques for calculating daily carbon gain, (2) to evaluate the Hsat (the daily period of I-saturated photosynthesis) model of daily production relative to models based on instantaneous photosynthesis vs irradiance (P vs I) and (3) to provide some guidance for the temporal density of irradiance data required for accurate estimation of daily carbon gain. Monthly measures of the P vs I response of an eelgrass Zostera marina L. population were used to predict rates of daily carbon gain from continuous in situ recordings of I. Daily integrated I was not a reliable predictor of daily production. Numerical (iterative) integration of Hsat was much more reliable but required repeated measures of I within a day, as did numerical integration of P vs I. Analytical (non-iterative) models based only on observations of Im (noon) could not predict daily production accurately. Analytical models of P vs I and Hsat agreed with each other, however, indicating that the analytical models may be useful where the daily pattern of I is sinusoidal. Given the high degree oi temporal variability in coastal light environments, continuous monitoring of light availability may be required for calculation of daily production and reliable management of aquatic macrophyte populations

Temperature-induced shape morphing of bi-metallic structures

In this work, we study the thermo-mechanical behavior of metallic structures designed to significantly change shape in response to thermal stimuli. This behavior is achieved by arranging two metals with different coefficient of thermal expansion (CTE), Aluminum and Titanium, as to create displacement-amplifying units that can expand uniaxially. In particular, our design comprises a low-CTE bar surrounded by a high-CTE frame that features flexure hinges and thicker links. When the temperature increases, the longitudinal expansion of the high-CTE portion is geometrically constrained by the low-CTE bar, resulting in a large tangential displacement. Our design is guided by theoretical models and numerical simulations. We validate our approach by fabricating and characterizing individual units, one dimensional arrays and three-dimensional structures. Our work shows that structurally robust metallic structures can be designed for large shape changes. The results also demonstrate how harsh environmental conditions (e.g., the extreme temperature swings that are characteristic of extraterrestrial environments) can be leveraged to produce function in a fully passive way

REPRESENTING WITH LIGHT. VIDEO PROJECTION MAPPING FOR CULTURAL HERITAGE

In this paper, we describe a cross-disciplinary process that uses photogrammetric surveys as a precise basis for video projection mapping techniques. Beginning with a solid basis that uses geoinformatics technologies, such as laser scanning and photogrammetric survey, the method sets, as a first step, the physical and geometrical acquisition of the object. Precision and accuracy are the basics that allow the analysis of the artwork, both at a small or large scale, to evaluate details and correspondences. Testing contents at different scales of the object, using 3D printed replicas or real architectures is the second step of the investigation.The core of the process is the use of equations of collinearity into an interactive system such as Max 7, a visual programming language for music and multimedia, in order to facilitate operators to have a fast image correction, directly inside the interactive software. Interactivity gives also the opportunity to easily configure a set of actions to let the spectators to directly change and control the animation content. The paper goes through the different phases of the research, analysing the results and the progress through a series of events on real architecture and experiments on 3d printed models to test the level of involvement of the audience and the flexibility of the system in terms of content.The idea of using the collinearity equation inside da software Max 7 was developed for the M.Arch final Thesis by Massimo Visonà and Tommaso Pasini of the University of Venice (IUAV) in collaboration with the Digital Exhibit Postgraduate Master Course (MDE Iuav)

A framework for linking open environmental data

The concept of open government has promoted several initiatives in order to progress in their implementation in different governmental agencies. Generally, implantation is carried out, in the first place, based on transparency and the opening of data, giving citizens relevant information about their community. Within that information, data about the rational use of natural resources and care of the environment can be found. In this context, and taking into account the ongoing analysis, it was discovered that, apart from the positive measures taken for the progress of the implantation, the main existing flaw is the possibility to link and relate the existing data in different data sources. The linking of data will allow for a closer analysis that can generate a wider context for information. This paper is based on a PhD thesis in process whose aim is to generate a framework that allows the linking and relationship of information related to the environment published in different open government portals.Instituto de Investigación en InformáticaInstituto de Investigación en Informátic

Using earthworms as bioindicators of quality in no-till systems.

No Brasil, o plantio direto é o sistema de manejo do solo mais praticado. Dentre os diversos benefícios, o plantio direto promove as funções dos organismos, especialmente as minhocas, sobre a fertilidade do solo. Portanto, o presente estudo teve como objetivo avaliar as populações de minhocas, visando uma classificação da densidade e diversidade de minhocas em áreas sob plantio direto. As coletadas foram realizadas em fevereiro/março de 2010 e 2011, num total de 34 e 25 propriedades respectivamente em seis municípios da Bacia do Paraná 3, parte da bacia do lago de Itaipu. As minhocas foram amostradas no final da estação chuvosa, utilizando uma adaptação do Método para Biologia e Fertilidade em Solos Tropicais (TSBF), consistindo na coleta de 5 monolitos de 20 x 20 por 20 cm de profundidade, espaçados por mínimo 20 m um do outro, em um transecto linear. Foi realizada triagem manual no campo e as minhocas foram estocadas em sacos plásticos contendo solução de formaldeído 5%. As minhocas foram contadas e identificadas em nível de família, gênero e espécies. A simplificação da metodologia de amostragem objetivou possibilitar que os próprios agricultores avaliem as populações de minhocas em suas propriedades. A abundância de minhocas variou de 5 a 600 ind m-2 e 5 a 1150 ind m-2, respectivamente nas épocas de coletas em 2010 e 2011, enquanto o número de espécies variou de uma a seis em 2010 e de uma a sete em 2011 nas áreas sob plantio direto. Baseado neste estudo e em resultados de outros estudos anteriores, uma classificação para abundância e diversidade de minhocas em áreas sob plantio direto é proposta aqui, para Latossolos Vermelhos e regiões de clima quente do Paraná (Cfa Koeppen) : pobre >25 ind m-2 and 1 sp.; moderado ? 25 to 6 sp.Disponível online

Temperature-induced shape morphing of bi-metallic structures

In this work, we study the thermo-mechanical behavior of metallic structures designed to significantly change shape in response to thermal stimuli. This behavior is achieved by arranging two metals with different coefficient of thermal expansion (CTE), Aluminum and Titanium, as to create displacement-amplifying units that can expand uniaxially. In particular, our design comprises a low-CTE bar surrounded by a high-CTE frame that features flexure hinges and thicker links. When the temperature increases, the longitudinal expansion of the high-CTE portion is geometrically constrained by the low-CTE bar, resulting in a large tangential displacement. Our design is guided by theoretical models and numerical simulations. We validate our approach by fabricating and characterizing individual units, one dimensional arrays and three-dimensional structures. Our work shows that structurally robust metallic structures can be designed for large shape changes. The results also demonstrate how harsh environmental conditions (e.g., the extreme temperature swings that are characteristic of extraterrestrial environments) can be leveraged to produce function in a fully passive way

Requirement specifications for electronic voting systems

This paper presents an analysis of the requirements specification in electronic voting systems. In particular, it poses a specification that assumes a physical distributed architecture model with two networked intelligent units (Voting Terminal and Authorities Terminal). State Transition Diagrams and Use Cases are used in the modeling of the requirements. Finally, the model adaptation to two classes of different elections is analyzed: a national election of closed daily cycle and a university election with a cycle of several days, both with multiple objectives.Facultad de Informátic