Padé approximants for the acoustical characteristics of rigid frame porous media

In this paper it is shown that a number of theoretical models of the acoustical properties of rigid frame porous media, especially those involving ratios of Bessel functions of complex argument, can be accurately approximated and greatly simplified by the use of Padé approximation techniques. In the case of the model of Attenborough [J. Acoust. Soc. Am. 81, 93–102 (1987)] rational approximations are produced for the characteristic impedance, propagation constant, dynamic compressibility, and dynamic density, as a function of frequency and the material parameters. The model proposed by Stinson and Champoux

“The suffering black male body and the threatened white female body": ambiguous bodies in Candyman

This article explores the roles of monster and victim as experienced through the body, and considers how the relationship between violence and the body affects the presentation of these roles through close analysis of performance in Candyman (Bernard Rose, 1992). I aim to demonstrate that commitment to such a detailed approach, offers a more intricate and rewarding critical interaction, reflecting the complexity of narrative film. Consideration of the particulars of performance is crucial, in its affect on our engagement with the performer and their physical presence. Through this attention I intend to demonstrate how the seemingly fixed role of monster is in fact more fluid than first apparent, that monster and victim can co-exist in the same body. Candyman’s physicality and the way it is presented foregrounds the oscillations between violence and suffering, the relationship between the body and the violence inflicted on and by it, ambiguities which are also found in the heroine’s development, thus enhancing the film’s striking preoccupation with the shifting parallels between monster and victim.

Do consumers want public or private bodies to monitor animal friendly production and marketing schemes? And does trust matter?

Producing according to enhanced farm animal welfare (FAW) standards increases costs along the livestock value chain, especially for monitoring certified animal friendly products. In the choice between public or private bodies for carrying out and monitoring certification, consumer preferences and trust play a role. We explore this issue by applying logit analysis involving socio-economic and psychometric variables to survey data from Italy. Results identify marked consumer preferences for public bodies and trust in stakeholders a key determinant.

Regurgitated bodies: presenting and representing trauma in 'The Act of Killing'

Focusing on The Act of Killing, this chapter examines how an “ethics of realism” operates on three key cinematic arenas: genre, authorship and spectatorship. As far as genre is concerned, the film’s realist commitment emerges from where it is least expected, namely from Hollywood genres, such as the musical, the film noir and the western, which are used as documentary, that is to say, as a fantasy realm where perpetrators can confess to their crimes without restraints or fear of punishment, but which nonetheless retains the evidentiary weight of the audiovisual medium. Authorship, in turn, translates as Oppenheimer’s unmistakable auteur signature through his role of self-confessed “infiltrator” who disguises as a sympathiser of the criminals in order to gain first-hand access to the full picture of their acts. One of them, the protagonist Anwar Congo, is clearly affected by post-traumatic stress disorder, and his repetitive reliving of his killings is made to flare up in front of the camera so as to bring back the dead to the present time in their material reality, through his own body, including a harrowing scene of the actor’s unpredictable and uncontrollable retching as he re-enacts the killing of his victims through strangulation. Finally, in the realm of spectatorship, the usual process of illusionistic identification on the part of the spectator is turned onto its head by means of disguising these criminals as amateur filmmakers, led to shoot, act within, and then watch their own film within the film so as to force them to experience beyond any illusion the suffering they had caused.

The role of industry bodies in changing market practices through self-regulation: commercial property leasing in the UK

The UK government has sought to make changes to commercial property leasing practices. This has been the case since the recession of the 1990s. Industry self-regulation using an industry code of practice has been the vehicle for these changes. However, the code has had little direct success in changing practices. This is despite repeated threats of legislation as a constant backdrop to this initiative. The focus for this research is on the role of the industry bodies in the code initiative. They have been central to self-regulation in commercial leasing. Thus, the aim is to investigate the role of industry bodies in the process of institutional change. The context is industry self-regulation. The specific setting is commercial leasing. The main industry bodies in focus are the British Property Federation and Royal Institution of Chartered Surveyors. An existing model of institutional change forms the framework for the research. A chronological narrative is constructed from secondary data. This is analysed, identifying the actions of the industry bodies within the conceptual stages of the model. The analysis shows that the industry bodies had not acted as convincing agents of change for commercial leasing. In particular there was a lack of theorisation, a key stage in the process. The industry bodies did not develop a framework necessary to guide their members through the change process. These shortcomings of the industry bodies are likely to have contributed to the failure of the Code. However, the main conclusion is that, if industry self-regulation is led by government, then the state must work with industry bodies to harness their potential as champions and drivers of institutional change. This is particularly important in achieving change in institutionalised environments.

Melting Regime of the Anionic Phospholipid DMPG: New Lamellar Phase and Porous Bilayer Model

Aqueous dispersions of the anionic phospholipid dimyristoyl phosphatidylglycerol (DMPG) at pH above the apparent pK of DMPG and concentrations in the interval 70-300 mM have been investigated by small (SAXS) and wide-angle X-ray scattering, differential scanning calorimetry, and polarized optical microscopy. The order. disorder transition of the hydrocarbon chains occurs along an interval of about 10 degrees C (between T(m)(on) similar to 20 degrees C and T(m)(off) similar to 30 degrees C). Such melting regime was previously characterized at lower concentrations, up to 70 mM DMPG, when sample transparency was correlated with the presence of pores across the bilayer. At higher concentrations considered here, the melting regime persists but is not transparent. Defined SAXS peaks appear and a new lamellar phase L(p) with pores is proposed to exist above 70 mM DMPG, starting at similar to 23 degrees C (similar to 3 degrees C above T(m)(on)) and losing correlation after T(m)(off). A new model for describing the X-ray scattering of bilayers with pores, presented here, is able to explain the broad band attributed to in-plane correlation between pores. The majority of cell membranes have a net negative charge, and the opening of pores across the membrane tuned by ionic strength, temperature, and lipid composition is likely to have biological relevance.

Fano resonance in heavily doped porous silicon

Unexpectedly, the Fano resonance caused by the interference of continuum electron excitations with the longitudinal optical (LO) phonons was observed in random porous Si by Raman scattering. The analysis of the experimental data shows that the electron states trapped at the Si-SiO(2) interface dominate in the observed Raman scattering. The gap energy associated with the interface states was determined. Copyright (C) 2011 John Wiley & Sons, Ltd.

Discontinuous Galerkin approximation of two-phase flows in heterogeneous porous media with discontinuous capillary pressures

We design and investigate a sequential discontinuous Galerkin method to approximate two-phase immiscible incompressible flows in heterogeneous porous media with discontinuous capillary pressures. The nonlinear interface conditions are enforced weakly through an adequate design of the penalties on interelement jumps of the pressure and the saturation. An accurate reconstruction of the total velocity is considered in the Raviart-Thomas(-Nedelec) finite element spaces, together with diffusivity-dependent weighted averages to cope with degeneracies in the saturation equation and with media heterogeneities. The proposed method is assessed on one-dimensional test cases exhibiting rough solutions, degeneracies, and capillary barriers. Stable and accurate solutions are obtained without limiters. (C) 2010 Elsevier B.V. All rights reserved.

Accurate velocity reconstruction for Discontinuous Galerkin approximations of two-phase porous media flows

We consider Discontinuous Galerkin approximations of two-phase, immiscible porous media flows in the global pressure/fractional flow formulation with capillary pressure. A sequential approach is used with a backward Euler step for the saturation equation, equal-order interpolation for the pressure and the saturation, and without any limiters. An accurate total velocity field is recovered from the global pressure equation to be used in the saturation equation. Numerical experiments show the advantages of the proposed reconstruction. To cite this article: A. Ern et al., C R. Acad. Sci. Paris, Ser. 1347 (2009). (C) 2009 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.

Versatile microanalytical system with porous polypropylene capillary membrane for calibration gas generation and trace gaseous pollutants sampling applied to the analysis of formaldehyde, formic acid, acetic acid and ammonia in outdoor air

The analytical determination of atmospheric pollutants still presents challenges due to the low-level concentrations (frequently in the mu g m(-3) range) and their variations with sampling site and time In this work a capillary membrane diffusion scrubber (CMDS) was scaled down to match with capillary electrophoresis (CE) a quick separation technique that requires nothing more than some nanoliters of sample and when combined with capacitively coupled contactless conductometric detection (C(4)D) is particularly favorable for ionic species that do not absorb in the UV-vis region like the target analytes formaldehyde formic acid acetic acid and ammonium The CMDS was coaxially assembled inside a PTFE tube and fed with acceptor phase (deionized water for species with a high Henry s constant such as formaldehyde and carboxylic acids or acidic solution for ammonia sampling with equilibrium displacement to the non-volatile ammonium ion) at a low flow rate (8 3 nLs(-1)) while the sample was aspirated through the annular gap of the concentric tubes at 25 mLs(-1) A second unit in all similar to the CMDS was operated as a capillary membrane diffusion emitter (CMDE) generating a gas flow with know concentrations of ammonia for the evaluation of the CMDS The fluids of the system were driven with inexpensive aquarium air pumps and the collected samples were stored in vials cooled by a Peltier element Complete protocols were developed for the analysis in air of NH(3) CH(3)COOH HCOOH and with a derivatization setup CH(2)O by associating the CMDS collection with the determination by CE-C(4)D The ammonia concentrations obtained by electrophoresis were checked against the reference spectrophotometric method based on Berthelot s reaction Sensitivity enhancements of this reference method were achieved by using a modified Berthelot reaction solenoid micro-pumps for liquid propulsion and a long optical path cell based on a liquid core waveguide (LCW) All techniques and methods of this work are in line with the green analytical chemistry trends (C) 2010 Elsevier B V All rights reserved

Synthesis, characterization and adsorption properties of porous mixed valent diruthenium(II,III)-terephthalate and diruthenium(II,III)-adipate polymers

Two porous mixed valent diruthenium(II,III)-dicarboxylate compounds have been prepared and characterized by spectroscopic methods, X-ray diffraction and thermogravimetry. Crystalline solids of [Ru(2)(tere)(2)Cl] center dot 3.5H(2)O (tere=terephthalate) and [Ru(2)(adip)(2)Cl] center dot 1.5H(2)O (adip=adipate) consist of extended chains in which polymeric layers of multiply metal-metal bonded [Ru(2)](5+) cores are bridged by dicarboxylate ligands in paddlewheel type geometries. Units of [Ru(2)(dicarboxylate)(2)](n)(+) are linked by axial bridging chloride ions generating three-dimensional networks. The polymers loose non-bonded water molecules at low temperatures but do not undergo thermal decomposition below 280-300 degrees C. Both of compounds exhibit high BET surface areas, [Ru(2)(tere)(2)Cl]: 235 m(2) g(-1) and [Ru(2)(adip)(2)Cl]: 281 m(2) g(-1), and occlude similar numbers of mol of N(2) per mol of metal. The terephthalate ligand generated an organized structure with supermicropores (total pore size of 0.24 cm(3) g(-1)) while the adipate ligand led to a mesoporous structure (total pore sizes of 0.47 cm(3) g(-1)) for the corresponding diruthenium(II,III)-dicarboxylate polymers. (c) 2008 Elsevier B.V. All rights reserved.

Structure of polyaniline formed in different inorganic porous materials: A spectroscopic study

In this work, the electronic and structural characterization of polyaniline (PANI) formed in cavities of zeolites Y (ZY) and Mordenite (MOR) and montmorillonite (MMT) clay having Cu(II) as oxidant agent are presented. The formation of PANI and its structure is analyzed by Resonance Raman, UV-Vis-NIR, FT-IR and N K XANES techniques. In all cases the structure of PANT formed is different from the ""free"" polymer. The presence of azo bonds linked to phenazine-like rings are observed only for PANI-MMT composites, independent of the kind of oxidant agent employed in the synthesis. The presence of Cu(II) ions leads to the formation of Phenosafranine-like rings. The presence of these phenazine-like rings in the structure of confined PANT chains can also contribute to the enhancement of the thermal stability observed for all composites. (C) 2008 Elsevier Ltd. All rights reserved.