Bilayer graphene spectral function in RPA and self-consistent GW

We calculate the single-particle spectral function for doped bilayer graphene in the low energy limit, described by two parabolic bands with zero band gap and long range Coulomb interaction. Calculations are done using thermal Green's functions in both the random phase approximation (RPA) and the fully self-consistent GW approximation. RPA (in line with previous studies) yields a spectral function which apart from the Landau quasiparticle peaks shows additional coherent features interpreted as plasmarons, i.e. composite electron-plasmon excitations. In GW the plasmaron becomes incoherent and peaks are replaced by much broader features. The deviation of the quasiparticle weight and mass renormalization from their non-interacting values is small which indicates that bilayer graphene is a weakly interacting system. The electron energy loss function, $Im[-\epsilon^{-1}_q(\omega)]$ shows a sharp plasmon mode in RPA which in GW approximation becomes less coherent and thus consistent with the weaker plasmaron features in the corresponding single-particle spectral function

Derivation of a poroelastic flexural shell model

In this paper we investigate the limit behavior of the solution to quasi-static Biot's equations in thin poroelastic flexural shells as the thickness of the shell tends to zero and extend the results obtained for the poroelastic plate by Marciniak-Czochra and Mikeli\'c. We choose Terzaghi's time corresponding to the shell thickness and obtain the strong convergence of the three-dimensional solid displacement, fluid pressure and total poroelastic stress to the solution of the new class of shell equations. The derived bending equation is coupled with the pressure equation and it contains the bending moment due to the variation in pore pressure across the shell thickness. The effective pressure equation is parabolic only in the normal direction. As additional terms it contains the time derivative of the middle-surface flexural strain. Derivation of the model presents an extension of the results on the derivation of classical linear elastic shells by Ciarlet and collaborators to the poroelastic shells case. The new technical points include determination of the 2 X 2 strain matrix, independent of the vertical direction, in the limit of the rescaled strains and identification of the pressure equation. This term is not necessary to be determined in order to derive the classical flexural shell model.Comment: 32 page

Pressure jump interface law for the Stokes-Darcy coupling: Confirmation by direct numerical simulations

It is generally accepted that the effective velocity of a viscous flow over a porous bed satisfies the Beavers-Joseph slip law. To the contrary, interface law for the effective stress has been a subject of controversy. Recently, a pressure jump interface law has been rigorously derived by Marciniak-Czochra and Mikeli\'c. In this paper, we provide a confirmation of the analytical result using direct numerical simulation of the flow at the microscopic level.Comment: 25 pages, preprin

Strategi Peningkatan Mutu Pembelajaran Di Madrasah Aliyah Tahfizul Qur’an Isykarima Kecamatan Karangpandan Kabupaten Karanganyar

Penelitian ini bertujuan untuk : (1) Mendeskripsikan model strategi peningkatan mutu pembelajaran di Madrasah Aliyah Tahfizhul Qur’an Isy Karima Kecamatan Karangpandan Kabupaten Karanganyar. (2) Mendeskripsikan Faktor- faktor keberhasilan dalam peningkatan mutu pembelajaran di Madrasah Aliyah Tahfizhul Qur’an Isy Karima Kecamatan Karangpandan Kabupaten Karanganyar. Penelitian dilakukan dengan mengunakan pendekatan kualitatif. Strategi yang digunakan adalah studi etnographi. Penelitian dilaksanakan di Madrasah Aliyah Tahfizul Qur’an Isykarima Kecamatan Karangpandan Kabupaten Karanganyar. Untuk memperoleh data dalam penelitian ini digunakan metode : wawancara mendalam, observasi dan mencatat dokumen. Untuk memperoleh keabsahan (validitas) data peneliti mengunakan metode triangulasi data, Dependabilitas dan Konfirmabilitas. Hasil penelitian ini menemukan beberapa hal penting yang berhubungan dengan fokus penelitian, antara lain: (1). Strategi peningkatan mutu pembelajaran yang dilakukan madrasah Aliyah Tahfizul Qur’an meliputi : a. Strategi penyampaian pembelajaran meliputi metode yang digunakan guru sebagai pengajar dalam kegiatan belajar mengajar. b. Strategi pengorganisasian pembelajaran adalah sebuah metode Mengorganisasikan isi bidang studi yang telah dipilih untuk pembelajaran Strategi pengorganisasian meliputi strategi makro dan strategi mikro.c. Strategi pengolahan pembelajaran meliputi interaksi media, materi dan siswa. (2) Faktor faktor keberhasilan dalam peningkatan mutu pembelajaran di Madrasah Aliyah Tahfizul Qur’an Isykarima terdiri dari bebrapa faktor yaitu : Kurikulum, Staf pengajar, Siswa, Sumber belajar, Lingkungan belajar, Penilaian dan Tehnologi informasi. Kata kunci : mutu pembelajaran, strategi pembelajaran, faktor pendukung pembelajara

Energy Efficiency and Renewable Energy Management with Multi-State Power-Down Systems

A power-down system has an on-state, an off-state, and a finite or infinite number of intermediate states. In the off-state, the system uses no energy and in the on-state energy it is used fully. Intermediate states consume only some fraction of energy but switching back to the on-state comes at a cost. Previous work has mainly focused on asymptotic results for systems with a large number of states. In contrast, the authors study problems with a few states as well as systems with one continuous state. Such systems play a role in energy-efficiency for information technology but are especially important in the management of renewable energy. The authors analyze power-down problems in the framework of online competitive analysis as to obtain performance guarantees in the absence of reliable forecasting. In a discrete case, the authors give detailed results for the case of three and five states, which corresponds to a system with on-off states and three additional intermediate states “power save”, “suspend”, and “hibernate”. The authors use a novel balancing technique to obtain optimally competitive solutions. With this, the authors show that the overall best competitive ratio for three-state systems is 95 role= presentation style= box-sizing: border-box; max-height: none; display: inline; line-height: normal; text-align: left; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative; \u3e95 and the authors obtain optimal ratios for various five state systems. For the continuous case, the authors develop various strategies, namely linear, optimal-following, progressive and exponential. The authors show that the best competitive strategies are those that follow the offline schedule in an accelerated manner. Strategy “progressive” consistently produces competitive ratios significantly better than 2

Florentino Ariza's Loneliness Which Leads Into Self-Actualization in Love in the TIME of Cholera Movie

Loneliness is the condition when one lack of social relationship, particularly love or intimate relationship. The effect of loneliness can be varied. It must be painful but for some people it is the chance to deeply know about them so that they can achieve self actualization.Love In The Time Of Cholera is the film dealing mostly with loneliness issues. It tells about a man who is loyal to wait for his lover , Fermina Daza. In waiting his lover he suffers from loneliness yet he wants to be a respected man in society so that Fermina Daza will regard his presence as an honourable man. This study employs qualitative research which uses Psychological Approach. The concepts used in exploring Love in the Time of Cholera Movie are Self-concept, Loneliness, and Existential Approach and combined with Self Actualization theory proposed by Abraham Maslow. The analysis of the movie is based on the script and picture in the movie. That is why; it is worth also to use mise en scene studies to strengthen the analysis. This research reveals how Florentino Ariza can achieve his self actualization within his loneliness. Since he cannot bear on the pain, he gets rid of his loneliness by having sex with 622 women. Yet, he still feels lonely since his love need cannot be fulfilled. Actually, his sex habit only satisfies his physiological need which is the basic need in Maslow's hierarchy. Meanwhile, his loneliness which comes from his need of love will never be fulfilled if he cannot win Fermina's heart again because he also builds his self-concept to be an eternal love for Fermina Daza

Statistiques et visibilité des bibliothèques numériques : quelles stratégies de diffusion ?

7 p.We compared statistics of major digital libraries and we tried to see if there is a relationship between the volume of digital libraries and online visibility of each digitized document. Finally, we analyzed the consequences of the diffusion strategies of French digital libraries. The statistics were obtained by survey, gray literature, alexa.com, and Google Trends.Cet article compare les statistiques de consultation des principales bibliothèques numériques, interroge sur l'existence d'une relation entre le volume des entrepôts numériques et la visibilité sur Internet de chaque document numérisé, et analyse les conséquences des stratégies de diffusion des bibliothèques numériques françaises. Les données statistiques ont été obtenues par des moyens classiques (enquête, littérature grise) et plus originaux (alexa.com, Google Trends)

Asymptotic analysis of the Poisson-Boltzmann equation describing electrokinetics in porous media

We consider the Poisson-Boltzmann equation in a periodic cell, representative of a porous medium. It is a model for the electrostatic distribution of $N$ chemical species diluted in a liquid at rest, occupying the pore space with charged solid boundaries. We study the asymptotic behavior of its solution depending on a parameter $\beta$ which is the square of the ratio between a characteristic pore length and the Debye length. For small $\beta$ we identify the limit problem which is still a nonlinear Poisson equation involving only one species with maximal valence, opposite to the average of the given surface charge density. This result justifies the {\it Donnan effect}, observing that the ions for which the charge is the one of the solid phase are expelled from the pores. For large $\beta$ we prove that the solution behaves like a boundary layer near the pore walls and is constant far away in the bulk. Our analysis is valid for Neumann boundary conditions (namely for imposed surface charge densities) and establishes rigorously that solid interfaces are uncoupled from the bulk fluid, so that the simplified additive theories, such as the one of the popular Derjaguin, Landau, Verwey and Overbeek (DLVO) approach, can be used. We show that the asymptotic behavior is completely different in the case of Dirichlet boundary conditions (namely for imposed surface potential)