High-Reynolds shallow flow over an inclined sinusoidal bottom

An experimental study of a turbulent free-surface shallow flow over an inclined sinusoidal bottom with a fixed corrugation amplitude is presented. A parametric analysis is performed by varying both the inclination angle and the Reynolds number. We show that a “Pulse-Waves” regime, dominant for Reynolds smaller than 4 000, coexists with a “Roll-Waves” regime, which becomes dominant above this value. The relative energy of the waves is quantified in the parameter space. At Reynolds numbers larger than 8 000, these wave instabilities disappear

Linear stability of the 1D Saint-Venant equations and drag parameterizations

The stability of the homogeneous and steady flow based on the one-dimensional Saint-Venant equations for free surface and shallow water flows of constant slope is derived and displayed through graphs. With a suitable choice of units, the small and large drag limits, respectively, correspond to the small and large spatio-temporal scales of a linear system only controlled by the Froude number and two other dimensionless numbers associated with the bottom drag parameterization. Between the small drag limit, with the two families of marginal and non-dispersive shallow water waves, and the large drag limit, with the marginal and non-dispersive waves of the kinematic wave approximation, dispersive roll waves are detailed. These waves are damped or amplified, depending on the value of the three control parameters. The spatial generalized dispersion relations are also derived indicating that the roll-wave instability is of the convective type for all drag parameterizations

Cliff retreat and sea bed morphology under monochromatic wave forcing: Experimental study

Wave flume experiments have been performed to investigate a sandy cliff recession under monochromatic wave forcing. We varied the wave climate through the wave energy flux F and the surf similarity parameter j. The various processes of the cliff erosion cycle are depicted. The sea bed evolution mostly depends on the surf similarity parameter j. Steep planar (j > 0.7), gentle planar (0.5 < j < 0.7) and bared (j < 0.5) profiles are observed. We observed different bar dynamics, including steady and unsteady self-sustained oscillating states. Then we analyze the role of the eroded material on the cliff recession rate. We show that the cliff recession rate increases with the wave energy flux. Moreover, for a given wave energy flux, it is larger for a gentle planar profile than for a bared profile. However it is similar for both a bared profile and a steep planar profile. The cliff recession rate is not a monotonic function of the cliff height as the type of bottom profile influences the wave energy at the cliff

Sentence external elements in Catalan

This paper deals with the intonation of sentence external elements in Catalan. Its main purpose is to investigate the claim that there is a correspondence between prosodic form and grammatical function, so that syntactic independence is paralleled by prosodic independency. A related goal is to identify the mechanisms for signalling prosodic independency and/or dependency. To that end, a production experiment was devised eliciting the same sentences in different pitch ranges. The conclusion is that sentence external elements do not constitute a uniform category, either syntacticallyor prosodically. Quotation attributions are nearly always deaccented, appositions and non-restrictive relatives copy the pattern of the main phrase in a lower voice, some parentheticals are produced in a lower pitch range, while sentence adverbs do not show any tonal subordination at all

Physical Activity Guidelines for Children During and After Cancer Treatment

The purpose of part one of this thesis was to synthesize previous research and information about cancer, children and cancer, exercise and cancer, and the long and short-term effects of cancer. After synthesizing previous research, the second part of this thesis was to integrate that research and create a set of safe and effective physical activity guidelines for children during and after cancer treatment. Lastly, a sample exercise prescription was created. This prescription was tailored for a fictional young child in a pediatric cancer rehabilitation program. The design of the pediatric cancer rehabilitation program was based on meeting the needs of a child, physically, emotionally, and socially

The brain coding of multidimensional time series

Treballs finals del Màster de Fonaments de Ciència de Dades, Facultat de matemàtiques, Universitat de Barcelona. Curs: 2023-2024. Tutor: Ignasi Cos Aguilera[en] Electroencephalography (EEG) is a widely used technique in the study of brain function. A series of electrodes are placed on the scalp measuring an electric signal from a population of neurons over time. In this work, we will focus on the classification of EEG data. The conventional approach to analyse and classify EEG data employed feature extraction methods. However, deep learning techniques have started to be applied to this task. Among the different architectures, Graph Neural Networks (GNNs) have gained especial attention as EGG data contains complex spatiotemporal relations of high dimensionality, that can be interpreted as a graph. Given the potential of GNNs, we will propose a series of models and try to classify and separate different EEGs into three classes of motivation. The data comes from Cos, Deco, and Gilson, Unpublished, a study focusing on the influence of social motivation during a decision making task. Once the models are trained, we will discus their performance and compare them with the results from the aforementioned study

Les érotiques de Charlotte-Delbo

Que peut être un fonds érotique en bibliothèque ? Après les principes, la mise en oeuvre. La bibliothèque Charlotte-Delbo a frayé la voie

A Flow-induced phase inversion in immiscible polymer blends containing a liquid-crystalline polymer studied by in situ optical microscopy

International audienceThe phase inversion from a morphology of hydroxypropylcellulose in water (HPC50%) droplets in polydimethylsiloxane (PDMS) matrix to a morphology of PDMS droplets in HPC50% matrix can be induced by a change of shear rate, due to a viscosity ratio inversion. Such a process passing through four different transient morphological stages was studied by optical microscopy in a transparent shear device. In a certain concentration region, at a fixed shear rate, after sheets of PDMS were formed, the transition "hesitates" between phase inversion and refined starting morphology. The influence of PDMS concentration, shear rate, elasticity, and phase dimension on the final morphology was investigated and compared with different models given in the literature. The influence of concentration and shear rate on the duration of the transient flow was also studied. We propose a simplified model of breakage of filaments to explain a part of our result

An exploratory study of translanguaging practices in an online beginners' foreign language classroom

Translanguaging, the movement between communicative modes and features of different languages, is becoming an established research tradition in content-focused second language learning contexts. Pedagogic translanguaging practices nevertheless remain under-applied and under-researched in foreign language instructional settings, whether face-to-face or online. Synchronous virtual foreign language classrooms represent particularly rich spaces in which to begin to explore such practices, due to their multimodal affordances on the one hand and their technical constraints on the other. This study examines the pedagogic translanguaging practices that occur in a corpus of beginner-level Spanish online group tutorial data. A macro-level analysis of the interactional patterns that occur within this context reveals that both teacher participants follow closely the pedagogic prescriptions provided by the course designers with regard to the activities they employ. The finding that these activities offer limited opportunities for students to move between communicative modes and languages may be attributed in part to the emphasis on spoken interaction in this particular setting. A complementary micro-level analysis nevertheless reveals a more autonomous and intuitive approach to the teachers' choice of language when mediating such activities. Instances of student code-switching are relatively few, however. The study concludes with a call to course designers and practitioners to experiment with integrating a wide range of pedagogic translanguaging opportunities into online foreign language classroom activities, with a view to enhancing teaching, learning and communication in such environments