Ensemble inequivalence, bicritical points and azeotropy for generalized Fofonoff flows

We present a theoretical description for the equilibrium states of a large class of models of two-dimensional and geophysical flows, in arbitrary domains. We account for the existence of ensemble inequivalence and negative specific heat in those models, for the first time using explicit computations. We give exact theoretical computation of a criteria to determine phase transition location and type. Strikingly, this criteria does not depend on the model, but only on the domain geometry. We report the first example of bicritical points and second order azeotropy in the context of systems with long range interactions.Comment: 4 pages, submitted to Phys. Rev. Let

Thermodynamics of the self-gravitating ring model

We present the phase diagram, in both the microcanonical and the canonical ensemble, of the Self-Gravitating-Ring (SGR) model, which describes the motion of equal point masses constrained on a ring and subject to 3D gravitational attraction. If the interaction is regularized at short distances by the introduction of a softening parameter, a global entropy maximum always exists, and thermodynamics is well defined in the mean-field limit. However, ensembles are not equivalent and a phase of negative specific heat in the microcanonical ensemble appears in a wide intermediate energy region, if the softening parameter is small enough. The phase transition changes from second to first order at a tricritical point, whose location is not the same in the two ensembles. All these features make of the SGR model the best prototype of a self-gravitating system in one dimension. In order to obtain the stable stationary mass distribution, we apply a new iterative method, inspired by a previous one used in 2D turbulence, which ensures entropy increase and, hence, convergence towards an equilibrium state

Kemampuan Sepuluh Strain Jamur Melapukkan Empat Jenis Kayu Asal Manokwari

Kemampuan jamur melapukkan kayu bervariasi berdasarkan strain jamurnya. Tujuan penelitian ini mempelajari kemampuan sepuluh strain jamur pelapuk terhadap empat jenis kayu dari Manokwari. Contoh kayu yang diuji menggunakan metode Kolle flask mengacu pada SNI 7207: 2014. Hasil penelitian menunjukkan bahwa Chaetomium globosum dan Lentinus lepideus termasuk kelompok jamur yang memiliki kemampuan melapukkan kayu rendah, empat jenis jamur yaitu Schizophyllum commune, Trametes sp. HHBI-379, Trametes sp. HHBI-332, Phlebia brevispora berkemampuan sedang, adapun yang termasuk kelompok jamur berkemampuan melapukkan tinggi yaitu Polyporus arcularius, Polyporus sp., Pycnoporus sanguineus dan Tyromyces palustris. Kehilangan berat kayu tertinggi didapatkan pada kayu gubal Rhus taitensis yang diumpankan pada Polyporus sp., sedangkan kehilangan berat terendah tercatat pada kayu teras Haplolobus sp. yang diumpankan pada L. lepideus. Berdasarkan klasifikasi ketahanan kayu terhadap serangan jamur pelapuk, maka tiga jenis kayu yaitu Tetrameles nudiflora, Rhus taitensis, Pimeleodendron amboinicum termasuk kelompok kayu tidak-tahan (kelas IV), dan Haplolobus sp. termasuk kelompok kayu tahan terhadap jamur pelapuk (kelas II)

Analisa Gelombang Kejut Dan Pengaruhnya Terhadap Arus Lalu Lintas Di Jalan Sarapung Manado

Hubungan antara volume, kepadatan dan kecepatan merupakan elemen yang paling penting dalam teori arus lalu lintas. Ada banyak model yang menyatakan hubungan antara ketiga elemen sebagai unsur-unsur utama lalu lintas. Tiga model yang paling umum digunakan dalam praktek rekayasa lalu lintas adalah Greenshields, Greenberg dan Underwood. Karakteristik arus lalu lintas akan diperoleh berdasarkan model yang dipilih untuk mewakili data lapangan, kemudian menggunakan informasi tersebut untuk membuat analisa skenario insiden gelombang kejut.Penentuan model terpilih untuk perhitungan gelombang kejut didasarkan pada kriteria nilai uji R2 yang paling besar atau R2 > 0,5. Hasil analisa regresi diperoleh menggunakan bantuan software SPSS maupun dihitung dengan cara manual. Hasil yang diperoleh yaitu model Grenshield = 0,899, model Greenberg = 0,871, dan model Underwood = 0,928. Namun, disamping R2 perlu juga melihat karakteristik yang ditawarkan berdasarkan pada Kenyataan di lapangan. Hasil model harus benar secara logika dan statistik. Model Underwood tidak akan bekerja secara akurat ketika kondisi lalu lintas mengalami kemacetan. Oleh karena itu dipilih model Greenshields.Dari analisa yang dilakukan diperoleh hasil nilai Δt3-t2, QM dan Δt4-t yang dihitung tiap penambahan 5 menit (5, 10, 15, …, 60 menit.). Panjang antrian yang dapat terjadi selama durasi 5 menit adalah 980 meter (0,98 km). Waktu yang diperlukan kendaraan ketika memasuki kondisi macet dari kondisi normal adalah 5,64 menit, sedangkan waktu yang diperlukan untuk kembali ke keadaan normal dari kondisi macet adalah 5.839 menit

On Iterated Twisted Tensor Products of Algebras

We introduce and study the definition, main properties and applications of iterated twisted tensor products of algebras, motivated by the problem of defining a suitable representative for the product of spaces in noncommutative geometry. We find conditions for constructing an iterated product of three factors, and prove that they are enough for building an iterated product of any number of factors. As an example of the geometrical aspects of our construction, we show how to construct differential forms and involutions on iterated products starting from the corresponding structures on the factors, and give some examples of algebras that can be described within our theory. We prove a certain result (called ``invariance under twisting'') for a twisted tensor product of two algebras, stating that the twisted tensor product does not change when we apply certain kind of deformation. Under certain conditions, this invariance can be iterated, containing as particular cases a number of independent and previously unrelated results from Hopf algebra theory.Comment: 44 pages, 21 figures. More minor typos corrections, one more example and some references adde

Relation between antimicrobial use and resistance in Belgian pig herds

The aim of this study was to determine the link between the characteristics of antimicrobial therapy and occurrence of antimicrobial resistance in Escherichia coli of clinically healthy pigs exposed to antimicrobial treatments. A total of 918 Escherichia coli isolates were obtained from faecal samples, collected from 50 pig herds at the end of the fattening period and susceptibility was tested towards 15 different antimicrobial agents, using the disk diffusion method

Prevalensi Penyakit Gondok Endemik Pada Anak-anak Sekolah Dasar Di Beberapa Daerah Di Sumatera, Jawa Dan Bali

Suatu penyelidikan gondok endemik pada anak-anak Sekolah Dasar dilakukan di empat propinsi di beberapa daerah yang dikenal sebagai daerah endemik dalam bulan Juli dan Nopember 1972. Pemeriksaan dilakukan terhadap sejumlah 6703 anak-anak sekolah dari 46 Sekolah Dasar yang terdapat di 39 desa diberbagai tempat di propinsi Sumatera Utara, Sumatera Barat, Jawa Timur dan Bali.Penyelidikan ini menunjukkan bahwa angka prevalensi penyakit gondok pada anak sekolah di keempat propinsi berkisar antara 62.1% di Sumatera Utara dan 89.4% di Sumatera Barat. Walaupun Sumatera Barat menunjukkan angka prevalensi tertinggi, persentase gondok yang tampak pada anak-anak di Jawa Timur adalah yang tertinggi. Tidak seorangpun dari anak-anak yang diperiksa mempunyai gondok yang tergolong tingkat 3.Penelitian yang mendalam dan intensif dianjurkan sebelum dilaksanakan program pencegahan gondok endemik dengan iodisasi garam

Deformation of Curved BPS Domain Walls and Supersymmetric Flows on 2d K\"ahler-Ricci Soliton

We consider some aspects of the curved BPS domain walls and their supersymmetric Lorentz invariant vacua of the four dimensional N=1 supergravity coupled to a chiral multiplet. In particular, the scalar manifold can be viewed as a two dimensional K\"ahler-Ricci soliton generating a one-parameter family of K\"ahler manifolds evolved with respect to a real parameter, $\tau$. This implies that all quantities describing the walls and their vacua indeed evolve with respect to $\tau$. Then, the analysis on the eigenvalues of the first order expansion of BPS equations shows that in general the vacua related to the field theory on a curved background do not always exist. In order to verify their existence in the ultraviolet or infrared regions one has to perform the renormalization group analysis. Finally, we discuss in detail a simple model with a linear superpotential and the K\"ahler-Ricci soliton considered as the Rosenau solution.Comment: 19 pages, no figures. Typos corrected. Published versio

Invariant measures of the 2D Euler and Vlasov equations

We discuss invariant measures of partial differential equations such as the 2D Euler or Vlasov equations. For the 2D Euler equations, starting from the Liouville theorem, valid for N-dimensional approximations of the dynamics, we define the microcanonical measure as a limit measure where N goes to infinity. When only the energy and enstrophy invariants are taken into account, we give an explicit computation to prove the following result: the microcanonical measure is actually a Young measure corresponding to the maximization of a mean-field entropy. We explain why this result remains true for more general microcanonical measures, when all the dynamical invariants are taken into account. We give an explicit proof that these microcanonical measures are invariant measures for the dynamics of the 2D Euler equations. We describe a more general set of invariant measures, and discuss briefly their stability and their consequence for the ergodicity of the 2D Euler equations. The extension of these results to the Vlasov equations is also discussed, together with a proof of the uniqueness of statistical equilibria, for Vlasov equations with repulsive convex potentials. Even if we consider, in this paper, invariant measures only for Hamiltonian equations, with no fluxes of conserved quantities, we think this work is an important step towards the description of non-equilibrium invariant measures with fluxes.Comment: 40 page

Large deviation techniques applied to systems with long-range interactions

We discuss a method to solve models with long-range interactions in the microcanonical and canonical ensemble. The method closely follows the one introduced by Ellis, Physica D 133, 106 (1999), which uses large deviation techniques. We show how it can be adapted to obtain the solution of a large class of simple models, which can show ensemble inequivalence. The model Hamiltonian can have both discrete (Ising, Potts) and continuous (HMF, Free Electron Laser) state variables. This latter extension gives access to the comparison with dynamics and to the study of non-equilibri um effects. We treat both infinite range and slowly decreasing interactions and, in particular, we present the solution of the alpha-Ising model in one-dimension with $0\leq\alpha<1$