Lo chansonnier du roi. Luoghi e autori della lirica e della musica europee del Duecento

The Chansonnier du Roi (Paris, BNF f. fr. 844) is one of the most important sources for trouvère and troubadour lyrics, but also for early motets. Compiled around 1250 in Artois, the manuscript was later enriched with a unique collection of Occitan, French and Latin monophonic songs and instrumental dances in mensural notation. In the last decades, this chansonnier has been studied both from musicologists (Peraino and Haines) and romance philologists (Battelli and Asperti). Insights from these two fields, however, have never been brought together. This is my aim in this paper, focusing in particular on the later additions to the manuscript, about which I will also present new palaeographical evidence. My central hypothesis is that fr. 844 was brought to the Angevin court of Naples, probably around 1282, by Robert II of Artois. Here poets and artists from Northern France, Occitania and Aragon contributed to a multicultural milieu, where the chansonnier could have been exposed to new styles. Moreover, in comparison with similar sources, the compilers’ predilection for literary genres specifically connected to dance and music, as well as the use of mensural notation but also metrical irregularities and mise en texte strategies, show a unique interest in sound and performance. Ultimately, I expand the geography of thirteenth-century music, claiming Naples as major cultural centers of vernacular monophony

Designing stainless steel surfaces with anti-pitting properties applying laser ablation and organofluorine coatings

Long-lasting and superhydrophobic stainless steel with anti-pitting properties is achieved by modifying conventional AISI 304L through a two-step strategy: 1) application of a femtosecond surface laser ablation treatment to generate micro-nano structures on the surface; and 2) deposition of organofluorine nanometric coating. Samples with two different patterns, namely paraboloid- and cauliflower-like, are approached and investigated by means of contact angle hysteresis, X-ray photoelectron spectroscopy, and electrochemical techniques. Results indicate that the stainless steel surface acquires efficient anticorrosive properties due to the homogenization and refinement of the patterned microstructure into a magnetite rich phase, in combination with the formation of a carbonaceous and sol–gel layer. The adherent semiconducting oxide layer is stable over time in presence of an aggressive chloride environment. The prepared superhydrophobic surfaces prevent the steel substrates from getting wet with water, protecting them from the pitting corrosion caused by the electrolyte intrusion. The corrosion resistance is explained by a mechanism in which, in addition of the silane coating, the air trapped into the micro-nano patterned surfaces plays an important role.Peer ReviewedPostprint (author's final draft

Mechano‐Optical Characterization of Extrusion Flow Instabilities in Styrene‐Butadiene Rubbers: Investigating the Influence of Molecular Properties and Die Geometry

The extrusion flow instabilities of two commercial styrene-butadiene rubbers are investigated as they vary in isomer content (1,4-cis, 1,4-trans, and 1,2 con- formation) of the butadiene monomer and the molecular architecture (linear, branched). The investigated samples have similar multimodal molecular weight distribution. Two geometries of extrusion dies, slit and round capillary, are compared in terms of the type and the spatial characteristics of the flow instabilities. The latter are quantified using three methods: a highly pressure sensitive slit die, online and offline optical analysis. The highly pressure- sensitive slit die has three piezoelectric pressure transducers (Δt ≈ 10−3 s and Δp ≈ 10−5 bar) placed along the die length. The characteristic frequency (fChar.) of the flow instabilities follows a power law behavior as a function of shear\ua0rate to a 0.5 power for both materials, f Char. ∝ γ app.. A qualitative model is used\ua0to predict the spatial characteristic wavelength (λ) of the flow instabilities from round capillary to slit dies and vice versa. Slip velocities (Vs) are used to quantify the slippage at slit and round capillary dies as well

Thin-wall injection molding of polystyrene parts with coated and uncoated cavities

YesThe paper reports an investigation on the mechanical durability of textured thermoplastic surfaces together with their respective wetting properties. A range of laser-induced topographies with different aspect ratios from micro to nanoscale were fabricated on tool steel inserts using an ultrashort pulsed near infrared laser. Then, through micro-injection moulding the topographies were replicated onto polypropylene surfaces and their durability was studied systematically. In particular, the evolution of topographies on textured thermoplastic surfaces together with their wetting properties were investigated after undergoing a controlled mechanical abrasion, i.e. reciprocating dry and wet cleaning cycles. The obtained empirical data was used both to study the effects of cleaning cycles and also to identify cleaning procedures with a minimal impact on textured thermoplastic surfaces and their respective wetting properties. In addition, the use of 3D areal parameters that are standardised and could be obtained readily with any state-of-the-art surface characterisation system are discussed for monitoring the surfaces' functional response

Annular flow of viscoelastic fluids: Analytical and numerical solutions

This work provides analytical and numerical solutions for the linear, quadratic and exponential Phan–Thien–Tanner (PTT) viscoelastic models, for axial and helical annular fully-developed flows under no slip and slip boundary conditions, the latter given by the linear and nonlinear Navier slip laws. The rheology of the three PTT model functions is discussed together with the influence of the slip velocity upon the flow velocity and stress fields. For the linear PTT model, full analytical solutions for the inverse problem (unknown velocity) are devised for the linear Navier slip law and two different slip exponents. For the linear PTT model with other values of the slip exponent and for the quadratic PTT model, the polynomial equation for the radial location (β) of the null shear stress must be solved numerically. For both models, the solution of the direct problem is given by an iterative procedure involving three nonlinear equations, one for β, other for the pressure gradient and another for the torque per unit length. For the exponential PTT model we devise a numerical procedure that can easily compute the numerical solution of the pure axial flow problemCOMPETE, FEDER and Fundação para a Ciência e a Tecnologia (FCT) through projects PEst-C/CTM/LA0025/2013 (Strategic Project – LA 25 – 2013-2014), PTDC/EQU-FTT/113811/2009 and PTDC/EME-MFE/113988/2009. LLF and AMA would also like to thank FCT for financial support through the scholarships SFRH/BD/37586/2007 and SFRH/BPD/75436/2010, respectively

Biomimetic nanostructured surfaces for antifouling in dairy processing

In dairy pasteurization equipment, fouling is an ongoing problem. Indeed, when heated, milk and its derivatives generate mineral and proteinaceous deposits on stainless steel walls. This heat-induced fouling impairs the process through the addition of an increasing thermal resistance to the system. Deposits are also a threat to food safety as they provide micro-organisms with good settlement opportunities. As a consequence, fouling mitigating strategies are needed. Biomimetic surfaces in particular, inspired from the surface morphology of lotus leaf could be considered for their self-cleaning abilities. Its dual-scale roughness (i.e. a micro roughness supporpsed by nanoscale roughness) allows for the composite Cassie-Baxter wetting state due to air remaining trapped between the liquid and the solid surface. As a result, those surfaces possess very high contact angles (typically higher than 150o) and very low contact angle hysteresis (typically less than 10°). However, a major limitation of this type of surface is the difficulty to maintain a stable Cassie-Baxter state over time: depending on the experimental conditions (pressure, vibration, evaporation, surface defect) the liquid penetrates sooner or later into the structures degrading their anti-biofouling properties. To overcome this limitation, it has been proposed to impregnate the textured surface by a liquid of low surface tension (usually an inert oil not miscible with water). This led to SLIPS surfaces (Slippery Liquid-Infused Porous Surfaces). Even if these surfaces present low contact angle, their hysteresis is also almost null whatever the experimental conditions leading to antifouling properties [1].   This work aims at designing Cassie-Baxter and SLIPS surfaces and test them in dairy processing conditions to assess their antifouling properties. To this end, 316L stainless steel surfaces were texturized via femtosecond laser irradiation to generate dual-scale (cauliflower-like) structures [2]. Some of the fabricated surfaces underwent further modifications: (i) silanization with perfluorodecyltrichloro-silane or (ii) silanization followed by impregnation with a fluorinated oil to create Slippery Liquid Infused Porous Surfaces (SLIPS) [3]. All surfaces were tested for their fouling properties in a pilot pasteurization equipement (UMET-PIHM, Institut National de la Recherche Agronomique, Villeneuve d'Ascq) [4] allowing to mimick industrial conditions of the pasteurization process. Thorough characterizations were performed on the surfaces before and after fouling, to (i) establish clearly their surface properties (wettability, surface energy, roughness) and (ii) to investigate the impact of the different surface properties on heat-induced dairy fouling compared to a native stainless steel as reference. A wide range of analytical tools such as Goniometry, cross-section Electron Probe Micro-Analysis X-ray mappings, and Scanning Electron Microscopy were implemented to this end. Outstanding results were obtained regarding antifouling properties of dual-scaled roughness surfaces in dairy processing conditions, with a reduction of fouling by more than 90% in weight. References [1] T.-S. Wong, S. H. Kang, S. K. Y. Tang, E. Smythe, B. D. Hatton, A. Grinthal, and J. Aizenberg, ?Bioinspired self-repairing slippery surfaces with pressure-stable omniphobicity,? Nature, vol. 477, pp. 443?447, 2011. [2] A.-M. Kietzig, S. G. Hatzikiriakos, and P. Englezos, ?Patterned Superhydrophobic Metallic Surfaces,? Langmuir, vol. 25, no. 8, pp. 4821?4827, 2009. [3] A. K. Epstein, T.-S. Wong, R. A. Belisle, E. M. Boggs, and J. Aizenberg, ?Liquid-infused structured surfaces with exceptional anti-biofouling performance,? PNAS, vol. 109, no. 33, pp. 13182?13187, 2012. [4] M. Jimenez, G. Delaplace, N. Nuns, S. Bellayer, D. Deresmes, G. Ronse, G. Alogaili, M. Collinet-Fressancourt, and M. Traisnel, ?Toward the understanding of the interfacial dairy fouling deposition and growth mechanisms at a stainless steel surface: A multiscale approach,? J. Colloid an interface Sci., vol. 404, pp. 192?200, 2013

“Fracture” phenomena in shearing flow of viscous liquids

In start-up of steady shearing flow of two viscous unentangled liquids, namely low-molecular-weight polystyrene and α-D-glucose, the shear stress catastrophically collapses if the shear rate is raised above a value corresponding to a critical initial shear stress of around 0.1–0.3 MPa. The time dependence of the shear stress during this process is similar for the two liquids, but visualization of samples in situ and after quenching reveals significant differences. For α-D-glucose, the stress collapse evidently results from debonding of the sample from the rheometer tool, while in polystyrene, bubbles open up within the sample, as occurs in cavitation. Some similarities are pointed out between these phenomena and that of “lubrication failure” reported in the tribology literature.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47212/1/397_2004_Article_BF00368135.pd

Theoretical study of Oldroyd-b visco-elastic fluid flow through curved pipes with slip effects in polymer flow processing

The characteristics of the flow field of both viscous and viscoelastic fluids passing through a curved pipe with a Navier slip boundary condition have been investigated analytically in the present study. The Oldroyd-B constitutive equation is employed to simulate realistic transport of dilute polymeric solutions in curved channels. In order to linearize the momentum and constitutive equations, a perturbation method is used in which the ratio of radius of cross section to the radius of channel curvature is employed as the perturbation parameter. The intensity of secondary and main flows is mainly affected by the hoop stress and it is demonstrated in the present study that both the Weissenberg number (the ratio of elastic force to viscous force) and slip coefficient play major roles in determining the strengths of both flows. It is also shown that as a result of an increment in slip coefficient, the position of maximum velocity markedly migrates away from the pipe center towards the outer side of curvature. Furthermore, results corresponding to Navier slip scenarios exhibit non-uniform distributions in both the main and lateral components of velocity near the wall which can notably vary from the inner side of curvature to the outer side. The present solution is also important in polymeric flow processing systems because of experimental evidence indicating that the no-slip condition can fail for these flows, which is of relevance to chemical engineers

Polymer Flow Through Porous Media: Numerical Prediction of the Contribution of Slip to the Apparent Viscosity.

The flow of polymer solutions in porous media is often described using Darcy’s law with an apparent viscosity capturing the observed thinning or thickening effects. While the macroscale form is well accepted, the fundamentals of the pore-scale mechanisms, their link with the apparent viscosity, and their relative influence are still a matter of debate. Besides the complex effects associated with the rheology of the bulk fluid, the flow is also deeply influenced by the mechanisms occurring close to the solid/liquid interface, where polymer molecules can arrange and interact in a complex manner. In this paper, we focus on a repulsive mechanism, where polymer molecules are pushed away from the interface, yielding a so-called depletion layer in the vicinity of the wall. This depletion layer acts as a lubricating film that may be represented by an effective slip boundary condition. Here, our goal is to provide a simple mean to evaluate the contribution of this slip effect to the apparent viscosity. To do so, we solve the pore-scale flow numerically in idealized porous media with a slip length evaluated analytically in a tube. Besides its simplicity, the advantage of our approach is also that it captures relatively well the apparent viscosity obtained from core-flood experiments, using only a limited number of inputs. Therefore, it may be useful in many applications to rapidly estimate the influence of the depletion layer effect over the macroscale flow and its relative contribution compared to other phenomena, such as non-Newtonian effects

Rheo-PIV of a shear-banding wormlike micellar solution under large amplitude oscillatory shear

We explore the behavior of a wormlike micellar solution under both steady and large amplitude oscillatory shear (LAOS) in a cone–plate geometry through simultaneous bulk rheometry and localized velocimetric measurements. First, particle image velocimetry is used to show that the shear-banded profiles observed in steady shear are in qualitative agreement with previous results for flow in the cone–plate geometry. Then under LAOS, we observe the onset of shear-banded flow in the fluid as it is progressively deformed into the non-linear regime—this onset closely coincides with the appearance of higher harmonics in the periodic stress signal measured by the rheometer. These harmonics are quantified using the higher-order elastic and viscous Chebyshev coefficients e [subscript n] and v [subscript n] , which are shown to grow as the banding behavior becomes more pronounced. The high resolution of the velocimetric imaging system enables spatiotemporal variations in the structure of the banded flow to be observed in great detail. Specifically, we observe that at large strain amplitudes (γ [subscript 0] ≥ 1), the fluid exhibits a three-banded velocity profile with a high shear rate band located in-between two lower shear rate bands adjacent to each wall. This band persists over the full cycle of the oscillation, resulting in no phase lag being observed between the appearance of the band and the driving strain amplitude. In addition to the kinematic measurements of shear banding, the methods used to prevent wall slip and edge irregularities are discussed in detail, and these methods are shown to have a measurable effect on the stability boundaries of the shear-banded flow.Spain. Ministerio de Educación y Ciencia (MEC) (Project FIS2010-21924-C02-02