Erratum to: Flood Forecasting and Decision Making in the new Millennium. Where are We?

Water Resources Management -     

PDLC based on unsaturated polyester resins: molecular, morphological and thermo-optical analysis

A thermosetting matrix based on an unsaturated polyester resin was employed to realise a Polymer Dispersed Liquid Crystal (PDLC) system by a UV induced curing process. A molecular, morphological and thermo-optical characterisation of this system is presented. The chemical and structural properties were investigated by transmission FT-IR spectra in the near infrared frequency range and by dynamic-mechanical analysis. The results indicated that, upon curing, the matrix retains its intrinsic properties even for compositions very rich in the LC component (40 wt %). The morphology, investigated by optical and electron microscopy, showed phase separation before and after the curing process. Image analysis demonstrated that the cured materials had morphological features suitable to achieve interesting thermo-optical properties. In particular, the composition containing 40 wt % of LC exhibited the typical behaviour of a thermo-optical switch. Interesting optical bistability effects were also demonstrated for this particular composition.     

Influence of Feeding and Oviposition by Phytophagous Pentatomids on Photosynthesis of Herbaceous Plants

Feeding by herbivorous insects may change photosynthetic activity of host plants. We studied how feeding and oviposition by herbivorous stink bugs, Murgantia histrionica and Nezara viridula (Heteroptera: Pentatomidae), affect photosynthetic parameters of Brassica oleracea (savoy cabbage) and Phaseolus vulgaris (French bean). First, we measured photosynthetic gas exchange, chlorophyll fluorescence imaging, and emission of induced volatile organic compounds (VOC) immediately after feeding and during a post-feeding period. Photosynthesis decreased rapidly and substantially in B. oleracea and P. vulgaris infested by feeding bugs. Stomatal conductance did not decrease proportionally with photosynthesis; instead, inhibition of photosynthesis likely was due to a reduced diffusion of CO₂ in the mesophyll. We also measured the impact of oviposition per se and oviposition associated with feeding on photosynthetic parameters. A surprisingly large inhibition of photosynthesis was detected in cabbage leaves in response to oviposition by M. histrionica, even when oviposition was not associated with feeding activity. High resolution chlorophyll fluorescence imaging revealed that the damage to photochemistry caused by feeding and oviposition was restricted to the attacked areas. By contrast, the photochemical yield increased temporarily in the unaffected areas of the attacked leaves, indicating the onset of a compensatory response. Measurement of volatile organic compounds (VOC) revealed that feeding-damaged plants did not emit detectable amounts of VOC, indicating cellular damage (methanol and green leaf volatiles). However, feeding by M. histrionica induced emission of mono- and sesquiterpenes in savoy cabbage leaves. The different time-course of the induction of these two classes of terpenes may reflect the induction of two different biosynthetic pathways and indicate different roles of these terpenoids in tritrophic interactions.     

Preparation and Characterization of Nanostructured TiO2/Epoxy Polymeric Films

Summary: Titania‐containing coatings were prepared by cationic photopolymerization of an epoxy resin either by dispersion of preformed TiO₂ nanoparticles or by their in‐situ generation through a sol‐gel dual‐cure process. The kinetics of photopolymerization was evaluated by real‐time FT‐IR, studying the effect of the TiO₂ concentration. The properties of cured films were investigated, showing an increase of hydrophilicity on the surface of the coatings with increasing TiO₂ content. TEM analysis demonstrated that it is possible to achieve a significantly better control of the dispersion of the inorganic particles within the organic matrix by in‐situ generation of TiO₂, thus completely avoiding macroscopic phase separation and obtaining homogeneous, transparent coatings.

Bright‐field TEM micrograph for TIP20 dual‐cured film.     

PHANTOM: A Monte Carlo event generator for six parton final states at high energy colliders

PHANTOM is a tree level Monte Carlo for six parton final states at proton-proton, proton-antiproton and electron-positron colliders at and including possible interferences between the two sets of diagrams. This comprehends all purely electroweak contributions as well as all contributions with one virtual or two external gluons. It can generate unweighted events for any set of processes and it is interfaced to parton shower and hadronization packages via the latest Les Houches Accord protocol. It can be used to analyze the physics of boson-boson scattering, Higgs boson production in boson-boson fusion, and three boson production.

Program summary

Program title:PHANTOM (V. 1.0)Catalogue identifier: AECE_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AECE_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 175 787No. of bytes in distributed program, including test data, etc.: 965 898Distribution format: tar.gzProgramming language: Fortran 77Computer: Any with a UNIX, LINUX compatible Fortran compilerOperating system: UNIX, LINUXRAM: 500 MBClassification: 11.1External routines: LHAPDF (Les Houches Accord PDF Interface, http://projects.hepforge.org/lhapdf/), CIRCE (beamstrahlung for e⁺e⁻ ILC collider).Nature of problem: Six fermion final state processes have become important with the increase of collider energies and are essential for the study of top, Higgs and electroweak symmetry breaking physics at high energy colliders. Since thousands of Feynman diagrams contribute in a single process and events corresponding to hundreds of different final states need to be generated, a fast and stable calculation is needed.Solution method:PHANTOM is a tree level Monte Carlo for six parton final states at proton-proton, proton-antiproton and electron-positron colliders. It computes all amplitudes at and including possible interferences between the two sets of diagrams. The matrix elements are computed with the helicity formalism implemented in the program PHACT [1]. The integration makes use of an iterative-adaptive multichannel method which, relying on adaptivity, allows the use of only a few channels per process. Unweighted event generation can be performed for any set of processes and it is interfaced to parton shower and hadronization packages via the latest Les Houches Accord protocol.Restrictions: All Feynman diagrams are computed al LO.Unusual features: Phantom is written in Fortran 77 but it makes use of structures. The g77 compiler cannot compile it as it does not recognize the structures. The Intel, Portland Group, True64 HP Fortran 77 or Fortran 90 compilers have been tested and can be used.Running time: A few hours for a cross section integration of one process at per mille accuracy. One hour for one thousand unweighted events.References:

[1]

A. Ballestrero, E. Maina, Phys. Lett. B 350 (1995) 225, hep-ph/9403244; A. Ballestrero, PHACT 1.0, Program for helicity amplitudes Calculations with Tau matrices, hep-ph/9911318, in: B.B. Levchenko, V.I. Savrin (Eds.), Proceedings of the 14th International Workshop on High Energy Physics and Quantum Field Theory (QFTHEP 99), SINP MSU, Moscow, p. 303.

     

Spatial Networks of Hybrid I/O Automata for Modeling Excitable Tissue

We propose a new biological framework, spatial networks of hybrid input/output automata (SNHIOA), for the efficient modeling and simulation of excitable-cell tissue. Within this framework, we view an excitable tissue as a network of interacting cells disposed according to a 2D spatial lattice, with the electrical behavior of a single cell modeled as a hybrid input/ouput automaton. To capture the phenomenon that the strength of communication between automata depends on their relative positions within the lattice, we introduce a new, weighted parallel composition operator to specify the influence of one automata over another.The purpose of the SNHIOA model is to efficiently capture the spatiotemporal behavior of wave propagation in 2D excitable media. To validate this claim, we show how SNHIOA can be used to model and capture different spatiotemporal behavior of wave propagation in 2D isotropic cardiac tissue, including normal planar wave propagation, spiral creation, the breakup of spirals into more complex (potentially lethal) spatiotemporal patterns, and the recovery of the tissue to the rest via defibrillation.     

Nonlinear complementary filters on the special linear group

This article proposes a nonlinear complementary filter for the special linear Lie-group SL(3) that fuses low-frequency state measurements with partial velocity measurements and adaptive estimation of unmeasured slowly changing velocity components. The obtained results have direct application on the problem of filtering a sequence of image homographies acquired from low-quality video data. The considered application motivates us to derive results that provide adaptive estimation of the full group velocity or part of the group velocity that cannot be measured from sensors attached to the camera. We demonstrate the performance of the proposed filters on real world homography data.     

Thermosetting bismaleimide/reactive rubber blends: Curing kinetics and mechanical behavior

A maleimido-terminated butadiene–acrylonitrile copolymer was employed as an impact modifier for a commercial thermosetting bismaleimide resin. FTIR spectroscopy was used to monitor in real time the kinetics of the curing process in this blend system at different temperatures. The toughening agent was found to produce strong effects on the kinetics and mechanism of the curing process. The fracture toughness parameters K_c and G_c showed a substantial enhancement as the rubber content in the blend was increased. Only a modest reduction of the elastic modulus and of the compressive yield stress was brought about by incorporation of the impact modifier. © 1997 John Wiley & Sons, Inc. J Appl Polm Sci 65:979–990, 1997     

High-rate anaerobic treatment of Fischer-Tropsch wastewater in a packed-bed biofilm reactor

This study investigates the anaerobic treatment of an industrial wastewater from a Fischer-Tropsch (FT) process in a continuous-flow packed-bed biofilm reactor operated under mesophilic conditions (35 °C). The considered synthetic wastewater has an overall chemical oxygen demand (COD) concentration of around 28 g/L, mainly due to alcohols. A gradual increase of the organic load rate (OLR), from 3.4 gCOD/L/d up to 20 gCOD/L/d, was adopted in order to overcome potential inhibitory effects due to long-chain alcohols (>C6). At the highest applied OLR (i.e., 20 gCOD/L/d) and a hydraulic retention time of 1.4 d, the COD removal was 96% with nearly complete conversion of the removed COD into methane. By considering a potential of 200 tCOD/d to be treated, this would correspond to a net production of electric energy of about 8 × 10⁷ kWh/year.During stable reactor operation, a COD balance and batch tests showed that about 80% of the converted COD was directly metabolized through H₂⁻ and acetate-releasing reactions, which proceeded in close syntrophic cooperation with hydrogenotrophic and acetoclastic methanogenesis (contributing to about 33% and 54% of overall methane production, respectively). Finally, energetic considerations indicated that propionic acid oxidation was the metabolic conversion step most dependent on the syntrophic partnership of hydrogenotrophic methanogens and accordingly the most susceptible to variations of the applied OLR or toxicity effects.     

Enhancement of dye sonochemical degradation by some inorganic anions present in natural waters

The sonochemical degradation rate of the charged substrates Acid Blue 40 (AB40) and methylene blue (MB) is enhanced by scavengers of hydroxyl radicals such as bicarbonate, carbonate, bromide, iodide and (only in the case of AB40) nitrite. No rate variation was observed with chloride, nitrate or sulphate, excluding a mere ionic strength effect. Oxidation of bicarbonate, carbonate, bromide, iodide and nitrite yields the corresponding radicals CO₃⁻, Br₂⁻, I₂⁻ and NO₂, reactive but less than OH. Degradation enhancement can occur if these radicals are sonochemically formed on the surface of the collapsing cavitation bubbles and undergo there radical–radical recombination at a lesser extent than OH. In this way the radicals would be more available than OH for substrate degradation, both at the bubble surface and in the solution bulk, which could more than compensate for their lower intrinsic reactivity. The varied reactivity toward different substrates of the sonochemically formed radical species could then explain why nitrite inhibits MB degradation while enhancing that of AB40. The sonochemical formation of Br₂⁻, I₂⁻ and NO₂ can give rise to halogenation and nitration in addition to oxidation processes. In fact bromo-, iodo- and nitrophenols were detected upon sonication of phenol in the presence of the corresponding anions, but only at quite elevated concentration values of nitrite, bromide or iodide (above 10 mM). Formation of harmful halogeno- and nitroderivatives could therefore take place on sonication of some wastewater rather than of typical natural waters.