239 research outputs found
The - maximal regularity for the Beris-Edward model in the half-space
No full textIn this paper, we consider the model describing viscous incompressible liquid crystal flows, called the Beris-Edwards model, in the half-space.This model is a coupled system by the Navier-Stokes equations with the evolution equation of the director fields . The purpose of this paper is to prove that the linearized problem has a unique solution satisfying the maximal - regularity estimates, which is essential for the study of quasi-linear parabolic or parabolic-hyperbolic equations. Our method relies on the -boundedness of the solution operator families to the resolvent problem in order to apply operator-valued Fourier multiplier theorems. Consequently, we also have the local well-posedness for the Beris-Edwards model with small initial data.56 page
Beris hauseri Stuke 2004
No full text<i>Beris hauseri</i> Stuke, 2004 <p>− Chevenez (JU), Trou du Creugenat, 470 m, 568.900 /249.800, lisière xérothermophile prairie maigre/chênaie-hêtraie, 7– 21.6.1988, 2 ♀♀ *, Y. Gonseth leg.</p> <p>− Le Cachot (NE), tourbière, 1050 m, 2.7.1973, 1 ♀ *, W. Matthey leg.</p> <p>− Neuchâtel (NE), Grande Cassarde (Matile 61), 550 m, 561.8 / 165.5, lisière forêt thermophile, 5.6.1991, 1 ♀ *, J.-P. Haenni leg.</p> <p>− Neuchâtel (NE), Grande Cassarde (Matile 77), 545 m, 561.9/205.5, forêt thermophile/ lisière, 30.5.1998, 1 ♀ *; ditto, 21.6.1998, 2 ♀♀ *; ditto, 22.5.1999, 2 ♀♀; ditto, 30.5.1999, 1 ♀; ditto, 27.5.2001, 2 ♀♀; ditto, 31.5.2003, 1 ♀; ditto, 11.6.2005, 1 ♀ *, tous J.-P. Haenni leg.</p> <p>− Neuchâtel (NE), garide de l’Ermitage, forêt thermophile, 10.5.2000, 1 ♂ *, J.-P. Haenni leg.</p> <p>− St-Sulpice (NE), Bois de la Baume, 1170 m, 532.980/ 199.250, 11.6.2001, 1 ♀ *, J.-P. Haenni leg.</p> <p> (Dans le matériel ci-dessus, les spécimens marqués d’un astérisque * avaient été identifiés auparavant <i>B. strobli</i> par l’auteur). – Espèce nouvelle pour la Suisse.</p> <p> D’après Stuke (2004), <i>B. hauseri</i> est une espèce holarctique qui semble avoir une plus vaste répartition en Europe centrale que <i>B. strobli</i>. L’espèce est en particulier également présente à basse altitude, dans les plaines («im Flachland»). C’est apparemment le cas en Suisse, où elle est cependant présente aussi dans le Jura jusqu’à près de 1200 m d’altitude, même dans les stations froides comme les tourbières.</p>Published as part of <i>Haennii, Jean-Paul, 2019, Sur la présence en Suisse de Beris hauseri Stuke, 2004 (Diptera, Stratiomyidae), pp. 164-168 in Entomo Helvetica 12</i> on page 166, DOI: 10.5169/seals-985876, <a href="http://zenodo.org/record/8086730">http://zenodo.org/record/8086730</a>
The Beris-Edwards and the Ericksen-Leslie Models for Nematic Liquid Crystals
No full textI cristalli liquidi sono uno stato della materia intermedio tra quello solido e quello liquido. Tali materiali sono largamente utilizzati al giorno d’oggi per via delle loro proprietà ottiche, della loro sensibilità ai campi elettrici e magnetici e per via delle loro applicazioni nel campo farmaceutico. I modelli matematici che andiamo a studiare sono il modello di Ericksen-Leslie e il modello di Beris-Edwards. Per il primo dimostriamo l’esistenza locale e globale per dati piccoli con decadimento nel tempo per il caso libero, nel semispazio e nei domini esterni sufficientemente regolari tramite stime energetiche. Per quanto riguarda il modello di Beris-Edwards, consideriamo inizialmente il caso di assenza di velocità in 3 dimensioni. Dal punto di vista stazionario, dimostriamo l’esistenza di un punto critico per il funzionale associato che minimizzi il valore dell’energia tra tutti i punti critici non nulli (la cosiddetta Least Energy Solution). Dal punto di vista evolutivo, dimostriamo esistenza locale e globale con dati piccoli per alcuni tipi di non-linearità tramite stime lineari energetiche e di tipo Strichartz. Infine, dimostriamo la stima (p,q) massimale per le soluzioni del problema evolutivo lineare nel semispazio N-dimensionale tramite la R-solubilità del problema risolvente associato.
Liquid crystals are a state of matter intermediate between the solid state and the liquid state. Nowadays, these materials are largely used thanks to their optical properties, their sensibility to the electric and the magnetic fields and their applications to the pharmaceutical area. The mathematical models we study are the Ericksen-Leslie and the Beris-Edwards models. For the Ericksen-Leslie model we prove local well-posedness and the global existence and decay in time for small initial data in the free case, in the half-space and in exterior domains sufficiently smooth by energy estimates. For what concerns the Beris-Edwards model, we focus firstly on the case of absence of flow in 3 dimensions. From the stationary point of view, we prove the existence of a critical point for the related functional which minimizes the energy of all the critical points different from zero (the so-called Least Energy Solution). For what concerns the time-dependent system, we prove local and global existence with small initial data for a certain range of power nonlinearities by Strichartz estimates. Finally, we prove the maximal (p,q) regularity for the linear time-dependent general Beris-Edwards model in the N-dimensional half-space by the R-solvability of the correspondent resolvent system
Beris strobli Dusek & Rozkosny 1968
No full textBeris strobli Dušek & Rozkošný, 1968 − Bergün (GR), Preda, 1800 m, 778.850 /162.235, pente à aulne vert et adénostyle, 14.6.2008, 1 ♀, J.-P. Haenni leg. − Bergün (GR), Lai de Palpuogna (E), 1920 m, 780.160 /161.600, îles marécageuses tourbeuses à laîches et saules bas, 14.6.2008, 1 ♂, J.-P. Haenni leg. − Col de Bretolet (VS), [1923 m], 14.6.1976, 1♂, J. Aubert leg. (5 ♂♂ et 1 ♀, même localité, même date, se trouvent dans les collections du Musée cantonal de Zoologie de Lausanne, MZL) (spécimens identifiés auparavant B. strobli par l’auteur). Selon Stuke (2004), B. strobli semble être plutôt une espèce de moyenne montagne, du moins en Europe centrale. En Suisse, elle n’était pour l’instant connue que de deux localités de l’Engadine dans la région de Sils (Val Fex et Alp Prasura) (Stuke 2004). D’après les nouvelles données ci-dessus, elle est également présente ailleurs dans les Alpes grisonnes (région de l’Albula) ainsi que dans les Alpes valaisannes (Val d’Illiez). Par contre, B. strobli semble curieusement absente du Jura, même des stations froides d’altitude comme la tourbière du Cachot. Mais cette absence apparente est peut-être uniquement due à un manque de prospection. Quoiqu’il en soit, l’étude de matériel supplémentaire sera nécessaire pour préciser la connaissance encore très lacunaire de la distribution de ces deux espèces, en Suisse et en Europe en général. Clé de détermination La clé de Stuke (2004) permet l’identification des mâles de ce groupe d’espèces. Pour l’identification des femelles, on pourra utiliser la clé ci-dessous, basée principalement sur la forme de l’aperture médiane de la furca génitale. Pour observer la forme de cette structure faiblement sclérifiée, il est nécessaire d’éclaircir dans le KOH 10 % l’extrémité de l’abdomen, puis de dégager la furca soit en soulevant le sternite 8, soit en tirant délicatement vers l’arrière la base des cerques. Des photos de l’apex de l’abdomen avec la furca de ces trois espèces se trouvent également dans le travail de Stuke (2004). Clé des femelles des espèces européennes du groupe de Beris chalybata (abdomen sombre, front d’une largeur d’environ 1 ⁄ 3 de la largeur de la tête). 1. Fémurs et tibias entièrement jaunes; aperture de la furca génitale nettement plus longue que large, régulièrement arrondie à la base(Fig.2b)............. B. chalybata (Forster, 1771) – Fémurs et tibias plus ou moins assombris, au moins les fémurs postérieurs partiellement marqués de sombre; aperture de la furca génitale soit ovale et tronquée à la base, soit arrondie, presque aussi large que longue...................................................... 2 2. Aperture de la furca génitale plus longue que large, nettement tronquée à la base (Fig. 2a)....................................................................................................... B. hauseri Stuke, 2004 – Aperture de la furca génitale pratiquement aussi longue que large, régulièrement arrondie à la base (Fig. 2c).................................. B. strobli Dušek & Rozkošný, 1968Published as part of Haennii, Jean-Paul, 2019, Sur la présence en Suisse de Beris hauseri Stuke, 2004 (Diptera, Stratiomyidae), pp. 164-168 in Entomo Helvetica 12 on page 167, DOI: 10.5169/seals-985876, http://zenodo.org/record/808673
Shear flow dynamics in the Beris-Edwards model of nematic liquid crystals
No full text[eng] We consider the Beris-Edwards model describing nematic liquid crystal dynamics and restrict it to a shear flow and spatially homogeneous situation. We analyse the dynamics focusing on the effect of the flow. We show that in the co-rotational case one has gradient dynamics, up to a periodic eigenframe rotation, while in the non-co rotational case we identify the short- and long-time regimes of the dynamics. We express these in terms of the physical variables and compare with the predictions of other models of liquid crystal dynamics
Dissipation in nonequilibrium thermodynamics and its connection to the Rayleighian functional
No full textThis article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Antony N. Beris, Brian J. Edwards; Dissipation in nonequilibrium thermodynamics and its connection to the Rayleighian functional. Physics of Fluids 1 January 2024; 36 (1): 013102. https://doi.org/10.1063/5.0180407 and may be found at https://doi.org/10.1063/5.0180407. © 2024 Author(s). Published under an exclusive license by AIP Publishing.We examine quantitatively the role of dissipation in nonequilibrium thermodynamics and its connection to variational principles and the Rayleighian functional. The extremum of the Rayleighian is sometimes used to describe the inertialess (dissipation-dominated) dynamics of continuum systems, and it has been applied recently for the modeling of soft matter dynamics. We discuss how dissipation is considered within one of the modern complete descriptions of nonequilibrium thermodynamics, namely the single generator bracket formalism. Within this formalism, dissipation is introduced through the use of the dissipation bracket, describing irreversible dynamics, which is added to a Poisson bracket that describes the reversible dynamics of the system. A possible connection with the Rayleighian functional is then demonstrated that in all cases considered herein, the Rayleighian is equal to minus one half of the effective dissipation rate of the Lagrangian functional. The effective dissipation rate is obtained starting with an inertial (i.e., flux-based or velocity-based) system description, involving the Poisson bracket and the primitive part (i.e., without the entropy correction term) of the dissipative bracket. Several examples are discussed in detail, ranging from an algebraic model (damped oscillator) to continuum ones: modeling of fluid flow in porous particle media, viscous Newtonian compressible and incompressible fluid flows, and more interestingly, flow of a nematic liquid-crystalline material
Communication and Sustainable Development: Background Paper [keynote], 9th United Nations Roundtable on Communication for Development, 2004, FAO, Italy
No full textResponse of iron overload to deferasirox in rare transfusion-dependent anaemias: equivalent effects on serum ferritin and labile plasma iron for haemolytic or production anaemias.
No full textObjectives: It is widely assumed that, at matched transfusional iron-loading rates, responses to chelation
therapy are similar, irrespective of the underlying condition. However, data are limited for rare transfusiondependent
anaemias, and it remains to be elucidated if response differs, depending on whether the anaemia
has a primary haemolytic or production mechanism. Methods: The efficacy and safety of deferasirox
(Exjade) in rare transfusion-dependent anaemias were evaluated over 1 yr, with change in serum ferritin
as the primary efficacy endpoint. Initial deferasirox doses were 10–30 mg⁄ kg ⁄ d, depending on transfusion
requirements; 34 patients had production anaemias, and 23 had haemolytic anaemias. Results: Patients
with production anaemias or haemolytic anaemias had comparable transfusional iron-loading rates (0.31 vs.
0.30 mL red blood cells ⁄ kg ⁄ d), mean deferasirox dosing (19.3 vs. 19.0 mg⁄ kg ⁄ d) and baseline median
serum ferritin (2926 vs. 2682 ng ⁄ mL). Baseline labile plasma iron (LPI) levels correlated significantly with
the transfusional iron-loading rates and with serum ferritin levels in both cohorts. Reductions in median
serum ferritin levels were initially faster in the production than the haemolytic anaemias, but at 1 yr, similar
significant reductions of 940 and 617 ng ⁄mL were attained, respectively ()26.0% overall). Mean LPI
decreased significantly in patients with production (P < 0.0001) and haemolytic (P = 0.037) anaemias after
the first dose and was maintained at normal mean levels (<0.4 lm) subsequently. The most common
drug-related, investigator-assessed adverse events were diarrhoea (n = 16) and nausea (n = 12). Conclusions:
At matched transfusional iron-loading rates, the responses of rare transfusion-dependent anaemias
to deferasirox are similar at 1 yr, irrespective of the underlying pathogenic mechanism
Pengembangan Modul Pembelajaran Bab Persamaan Garis Lurus Berbasis Discovery Learning Pada Kelas VIII SMP
No full textPengembangan modul ini didasari oleh bahan ajar yang biasa dipakai dalam kegiatan belajar mengajar masih berupa gambaran materi persamaan garis lurus secara umum. Sehingga siswa kurang mampu belajar mandiri dan tidak aktif dalam proses pembelajaran di kelas. Modul yang dikembangan berbasis discovery learning guna menunjang proses pembelajaran. Discovery learning adalah metode pembelajaran yang melatih siswa dalam menemukan suatu konsep dan prinsip untuk mendukung tercapainya tujuan pembelajaran. Tujuan dari penelitian ini adalah untuk mengembangkan modul matematika berbasis discovery learning pada materi persamaan garis lurus dengan harapan dapat mengetahui tingkat kevalidan dan kepraktisan produk yang telah dikembangkan. Selain itu, modul matematika berbasis discovery learning pada materi persamaan garis lurus digunakan sebagaisarana dalam meningkatkan hasil belajar siswa di SMP PGRI 01 Singosari. Model pembelajaran matematika berbasis discovery learning pada materi persamaan garis lurus dikembangkan berdasarkan model Thiagarajan 4D yang dimodifikasi. Tahap awal define (pendefinisian) yang mencakup lima pokok yaitu, analisis tujuan awal, analisis siswa, analisis tugas, analisis konsep, dan perumusan tujuan pembelajaran. Tahap kedua desaign (perancangan) dengan melakukan penyusunan tes, pemilihan media, pemilihan format. Tahap ketiga develop pengembangan) dengan mengembangkan produk awal yang akan divalidasi dan direvisi oleh para ahli, selanjutnya dilakukan uji coba produk yang akan menghasilkan produk akhir. Data pada penelitian ini terdiri atas data kuantitatif, data kualitatif dan data hasil belajar siswa. Data kuantitatif diperoleh dari pengisian angket validasi oleh validator ahli media pembelajaran, ahli materi, dan ahli praktisi lapangan untuk menentukkan kevalidan. Modul pembejaran ini praktis digunakan dalam pembelajaran, hal ini dilihat dari respon siswa yang terhadap modul, yakni mendapat nilai sebesar 3,67 artinya siswa memberikan respon yang sangat positifterhadap modul. Nilai pretest dan posttest siswa menunjukkan belajar siswa, yaitu dari 71,33 menjadi 84,19 dan menunjukkan nilai gainscore 0,77 dengan efektifitas tinggi. Data kualitatif diperoleh dari pengisian angket berupa komentar dan saran oleh ahli media pembelajaran, ahli materi, ahli praktisi lapangan, dan siswa. Modul materi persamaan garis lurus berbasis discovery learning dapat mengaktifkan siswa dan digunakan sebagai bahan ajar selain buku paket siswa terutama oleh gur
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