Euclidean Supersymmetry, Twisting and Topological Sigma Models

We discuss two dimensional N-extended supersymmetry in Euclidean signature and its R-symmetry. For N=2, the R-symmetry is SO(2)\times SO(1,1), so that only an A-twist is possible. To formulate a B-twist, or to construct Euclidean N=2 models with H-flux so that the target geometry is generalised Kahler, it is necessary to work with a complexification of the sigma models. These issues are related to the obstructions to the existence of non-trivial twisted chiral superfields in Euclidean superspace.Comment: 8 page

Nonlinear atom optics and bright gap soliton generation in finite optical lattices

We theoretically investigate the transmission dynamics of coherent matter wave pulses across finite optical lattices in both the linear and the nonlinear regimes. The shape and the intensity of the transmitted pulse are found to strongly depend on the parameters of the incident pulse, in particular its velocity and density: a clear physical picture for the main features observed in the numerical simulations is given in terms of the atomic band dispersion in the periodic potential of the optical lattice. Signatures of nonlinear effects due the atom-atom interaction are discussed in detail, such as atom optical limiting and atom optical bistability. For positive scattering lengths, matter waves propagating close to the top of the valence band are shown to be subject to modulational instability. A new scheme for the experimental generation of narrow bright gap solitons from a wide Bose-Einstein condensate is proposed: the modulational instability is seeded in a controlled way starting from the strongly modulated density profile of a standing matter wave and the solitonic nature of the generated pulses is checked from their shape and their collisional properties

A numerical-experimental method for damage location based on rotation fields spatial differentiation

This paper presents a structural damage location method that decreases the number of spatial differentiations needed to compute modal curvature fields. The method is numerically and experimentally applied to isotropic and laminated rectangular plates, respectively. A speckle shear interferometer is used to measure the rotation fields of the laminated plate, while the isotropic plate is analysed by finite elements. It was found that the Gaussian differentiation is the most suited technique to compute the curvature fields. It is also demonstrated the superior performance of the curvature method using measured rotation fields instead of measured displacement fields

Damage localization in laminated composite plates using double pulse-electronic holographic interferometry

One method for the damage localization of impact damage in laminated composite plates, based on their vibrational characteristics, is presented in this paper. This method uses double pulse-electronic holographic interferometry for mode shapes acquisition and the differences in curvatures. The rotations and curvatures are numerically obtained. The method is applied to a carbon fibre reinforced epoxy rectangular plate, free in space, subjected to two cases of impact damage. It is shown that the method based on curvatures allows for the localization of both cases of damage, which can be undetected by visual, X-ray or C-Scan inspections. The best localizations are achieved by selecting and applying the method to the most changed mode

Irradiation as a novel approach to improve quality of Tropaeolum majus L. flowers: benefits in phenolic profiles and antioxidant activity

Edible flowers are increasingly used in food preparations, requiring new approaches to improve their conservation and safety. Food irradiation, particularly electron beam and gamma irradiation, is legally recognized to extend shelf life, improve hygienic quality and disinfest foods. Garden nasturtium (Tropaeolum majus L.) flowers are widely used in food preparations, being also known for their antioxidant properties and high content of phenolics. The purpose of this study was to evaluate the dose-response effects of gamma and electron beam irradiation (unirradiated and doses of 0.5, 0.8 and 1 kGy) on its antioxidant activity and phenolic compounds. Kaempferol-O-hexoside-O-hexoside was the most abundant compound, while pelargonidin-3-O-sophoroside was the major anthocyanin. The flowers showed high antioxidant activity, in particular as reducing agents. The interaction among the effects of irradiation dose and irradiation technology was a significant source of variation for all parameters. In general, irradiated samples gave higher antioxidant activity, maybe due to their higher amounts of phenolic compounds. Anthocyanins were the sole compounds negatively affected by irradiation. These differences were reflected in the linear discriminant analysis, which allowed the perfect separation of the applied doses, as also both irradiation technologies. Accordingly, irradiation represents a feasible technology to preserve the quality of edible flowers.The authors are grateful to Fundação para a Ciência e a Tecnologia (FCT, Portugal) for financial support to CIMO (strategic project ), João C.M. Barreira (SFRH/BPD/72802/2010 grant) and L. Barros (“Compromisso para a Ciência 2008” contract). CNEN, CAPES, CNPq and IPEN-CNEN/SP for financial support to Amanda Koike. This research is included in a Bilateral action FCT-CNPq, Portugal/Brazil 2014

How gamma and electron-beam irradiations modulate phenolic profile expression in Melissa officinalis L. and Melittis melissophyllum L.

Owing to the overall increase in herbal infusions’ consumption, there's a progressively higher need of suitable plant material, as well as adequate conservation techniques to maintain its quality. Among, the available technologies, irradiation is gaining interest as a feasible preservation method. In line with this approach, this wok was designed to evaluate the effects of electron-beam and gamma irradiation over the phenolic profiles of two plant species Melissa officinalis L. (LB) and Melittis melissophyllum L. (BB). Individual phenolics were characterized by high-performance liquid chromatography coupled to a diode array detector and a mass spectrometer (HPLC-DAD-ESI/MS). Irradiated samples showed a general increase in individual phenolic contents, especially in lithospermic acid A in LB and 5-O-caffeoylquinic acid in BB. Thus, this study revealed the potential usefulness of both conservation technologies when employed to this type of plants.Ministry of Agriculture, Portugal (Project PRODER/FEADER/EU no. 53514), for financial support of the work and E. Pereira grant; Foundation for Science and Technology (FCT, Portugal) for financial support to CIMO (PEst-OE/AGR/UI0690/2014), CTN (RECI/AAG-TEC/0400/2012), L. Barros (BPD/107855/2015) and J.C.M. Barreira (BPD/72802/2010). Prof A. Chmielewski, Director of INCT, and Dr. A. Rafalski, for electron-beam irradiations.info:eu-repo/semantics/publishedVersio

Gravitational lensing as a contaminant of the gravity wave signal in CMB

Gravity waves (GW) in the early universe generate B-type polarization in the cosmic microwave background (CMB), which can be used as a direct way to measure the energy scale of inflation. Gravitational lensing contaminates the GW signal by converting the dominant E polarization into B polarization. By reconstructing the lensing potential from CMB itself one can decontaminate the B mode induced by lensing. We present results of numerical simulations of B mode delensing using quadratic and iterative maximum-likelihood lensing reconstruction methods as a function of detector noise and beam. In our simulations we find the quadratic method can reduce the lensing B noise power by up to a factor of 7, close to the no noise limit. In contrast, the iterative method shows significant improvements even at the lowest noise levels we tested. We demonstrate explicitly that with this method at least a factor of 40 noise power reduction in lensing induced B power is possible, suggesting that T/S=10^-6 may be achievable in the absence of sky cuts, foregrounds, and instrumental systematics. While we do not find any fundamental lower limit due to lensing, we find that for high-sensitivity detectors residual lensing noise dominates over the detector noise.Comment: 6 pages, 2 figures, submitted to PR

Perennial spotted rockrose as a source of Ellagitannins with therapeutic interest: influence of drying and extraction conditions

The ellagitannins are a diverse class of hydrolysable tannins, a type of polyphenols present in some fruits, medicinal plants, nuts and seeds. They are complex derivatives of ellagic acid characterized by one or more hexahydroxydiphenoyl moieties esterified to a sugar, usually glucose [1]. These compounds play an important role in human nutrition and are endowed with numerous biological properties, including antioxidant, anti-inflammatory, anticancer, antiatherosclerotic, antihepatotoxic, antibacterial and anti-HIV replication activities [1-3], being therefore interesting molecules for medicinal and therapeutic applications. A previous work of our research team highlighted the perennial spotted rockrose (Tuberaria lignosa (Sweet) Samp.) as a rich source of ellagitannins, namely punicalagin [2]. In this study, the influence of drying and extraction conditions on the ellagitannins content from perennial spotted rockrose flowering aerial parts was evaluated. Wild specimens were gathered in the Northeast region of Portugal and then freeze-dried immediately after gathering or shade-dried in a dark and dry place at room temperature for 30 days. Subsequently, dried samples were extracted adding them to boiling water and left to stand at room temperature for 5 min, or boiling them for 5 min plus 5 min at room temperature. The ellagitannins analysis was performed by HPLC-DAD-ESI/MS. The effects of drying and extraction conditions were evaluated by analysis of variance (ANOVA) using the General Linear Model procedure. The most abundant ellagitannins were punicalagin isomers and punicalagin gallate isomers, being the highest levels detected in freeze-dried samples. Additionally, higher amounts of these compounds were achieved with longer extraction time (5 min + 5 min), in both shade- and freeze-dried samples. Thus, from the obtained results, it might be concluded that freeze-drying and longer extraction time are the preferable conditions to obtain high levels of ellagitannins with therapeutic interest from perennial spotted rockrose samples

Phenolic profiling of Veronica spp. grown in mountain, urban and sand soil environments

Veronica (Plantaginaceae) genus is widely distributed in different habitats. Phytochemistry studies are increasing because most metabolites with pharmacological interest are obtained from plants. The phenolic compounds of V. montana, V. polita and V. spuria were tentatively identified by HPLC-DAD-ESI/MS. The phenolic profiles showed that flavones were the major compounds (V. montana: 7 phenolic acids, 5 flavones, 4 phenylethanoids and 1 isoflavone; V. polita: 10 flavones, 5 phenolic acids, 2 phenylethanoids, 1 flavonol and 1 isoflavone; V. spuria: 10 phenolic acids, 5 flavones, 2 flavonols, 2 phenylethanoids and 1 isoflavone), despite the overall predominance of flavones. V. spuria presented the highest contents in all groups of phenolic compounds, except flavones, which did not show differences among the assayed species. The detected differences proved to be significant, as confirmed by objects distribution obtained in PCA. Overall, these species might be considered good sources of phenolic compounds for industrial or pharmacological applications

Damage localization in laminated composite plates using mode shapes measured by pulsed TV holography

Three methods for the damage localization of impact damage in laminated composite plates, based on their vibrational characteristics, are presented in this paper. These methods use double pulse TV holography with acoustic excitation for mode shapes acquisition and the differences in translations, rotations and curvatures. The rotations and curvatures are obtained by numerical differentiation of mode shapes translations using a differentiation/smoothing technique. The methods are applied to a carbon fiber reinforced epoxy rectangular plate, free in space, subjected to two cases of impact damage. It is shown that the method based on curvatures allows the localization of both cases of damage, which can be undetected by visual, X-ray or C-scan inspections. The best localizations are achieved by selecting and applying the method to the most changed mode.Three methods for the damage localization of impact damage in laminated composite plates, based on their vibrational characteristics, are presented in this paper. These methods use double pulse TV holography with acoustic excitation for mode shapes acquisition and the differences in translations, rotations and curvatures. The rotations and curvatures are obtained by numerical differentiation of mode shapes translations using a differentiation/smoothing technique. The methods are applied to a carbon fiber reinforced epoxy rectangular plate, free in space, subjected to two cases of impact damage. It is shown that the method based on curvatures allows the localization of both cases of damage, which can be undetected by visual, X-ray or C-scan inspections. The best localizations are achieved by selecting and applying the method to the most changed mode