Effect of turbulent fluctuations on the drag and lift forces on a towed sphere and its boundary layer

The impact of turbulent fluctuations on the forces exerted by a fluid on a towed spherical particle is investigated by means of high-resolution direct numerical simulations. The measurements are carried out using a novel scheme to integrate the two-way coupling between the particle and the incompressible surrounding fluid flow maintained in a high-Reynolds-number turbulent regime. The main idea consists in combining a Fourier pseudo-spectral method for the fluid with an immersed-boundary technique to impose the no-slip boundary condition on the surface of the particle. Benchmarking of the code shows a good agreement with experimental and numerical measurements from other groups. A study of the turbulent wake downstream the sphere is also reported. The mean velocity deficit is shown to behave as the inverse of the distance from the particle, as predicted from classical similarity analysis. This law is reinterpreted in terms of the principle of "permanence of large eddies" that relates infrared asymptotic self-similarity to the law of decay of energy in homogeneous turbulence. The developed method is then used to attack the problem of an upstream flow that is in a developed turbulent regime. It is shown that the average drag force increases as a function of the turbulent intensity and the particle Reynolds number. This increase is significantly larger than predicted by standard drag correlations based on laminar upstream flows. It is found that the relevant parameter is the ratio of the viscous boundary layer thickness to the dissipation scale of the ambient turbulent flow. The drag enhancement can be motivated by the modification of the mean velocity and pressure profile around the sphere by small scale turbulent fluctuations.Comment: 24 pages, 22 figure

Exploring Bs→Ds(∗)±K∓B_s \to D_s^{(*)\pm} K^\mp Decays in the Presence of a Sizable Width Difference ΔΓs\Delta\Gamma_s

The $B_s \to D_s^{(*)\pm} K^\mp$ decays allow a theoretically clean determination of $\phi_s+\gamma$, where $\phi_s$ is the $B^0_s$-$\bar B^0_s$ mixing phase and $\gamma$ the usual angle of the unitarity triangle. A sizable $B_s$ decay width difference $\Delta\Gamma_s$ was recently established, which leads to subtleties in analyses of the $B_s \to D_s^{(*)\pm} K^\mp$ branching ratios but also offers new "untagged" observables, which do not require a distinction between initially present $B^0_s$ or $\bar B^0_s$ mesons. We clarify these effects and address recent measurements of the ratio of the $B_s\to D_s^\pm K^\mp$, $B_s\to D_s^\pm\pi^\mp$ branching ratios. In anticipation of future LHCb analyses, we apply the SU(3) flavour symmetry of strong interactions to convert the $B$-factory data for $B_d\to D^{(*)\pm}\pi^\mp$, $B_d\to D_s^{\pm}\pi^\mp$ decays into predictions of the $B_s \to D_s^{(*)\pm} K^\mp$ observables, and discuss strategies for the extraction of $\phi_s+\gamma$, with a special focus on untagged observables and the resolution of discrete ambiguities. Using our theoretical predictions as a guideline, we make simulations to estimate experimental sensitivities, and extrapolate to the end of the planned LHCb upgrade. We find that the interplay between the untagged observables, which are accessible thanks to the sizable $\Delta\Gamma_s$, and the mixing-induced CP asymmetries, which require tagging, will play the key role for the experimental determination of $\phi_s+\gamma$.Comment: 21 pages, 7 figures, matches published versio

German Longings:A Dialogue on the Promises and Dangers of National Stereotypes

Germanness is always already entangled with the complicated and torn history of Germany, as it continues to be haunted by the specter of the war. This chapter engages with the issue of Germanness in popular music from two different personal perspectives, one Dutch, and one German, and it navigates between issues of national identity and stereotyping through the lens of popular music. It explores the fascination for, and struggle with, and at times, even longings for Germanness as it asks: What is German music, and how do we, as listeners with our specific classed, gendered, aged, and national biographies, negotiate such sounds? By first drawing on the Dutch perspective on Germanness as “exotic other,” the chapter provides an outside view on German stereotypes and irony in popular music as a means of reflecting on other national identifications, such as the author’s Dutchness. Secondly, this dialogic chapter questions stereotypes and irony as productive means of complicating national identification, while also problematizing the increasing banalization and naturalization of the German nation in contemporary German pop. Finally, this chapter argues for a continuous reflection on naturalized productions of togetherness and national belonging instead of alienation and strangeness, and a more reflexive stance towards the tropes of stereotypes and irony for their ambiguity and dangers of infelicitous appropriation. <br/

Entry and exit patterns of "toxic" firms

We pair an establishment-level dataset from Texas with public information available in the Toxics Release Inventory (TRI) to evaluate the standing of dirty industries in Texas census tracts with a focus on environmental justice concerns. The share of nonwhite residents in a tract is positively correlated with the number of TRI-reporting firms and an inverse-U-shaped relationship characterizes the number of TRI-reporting firms and a tract's median income. Even after controlling for factor prices and other covariates which might drive firm location decisions, entrants that report to the TRI are more likely to locate in areas with a higher share of nonwhite residents. Firms that report to the TRI are also more likely to enter areas with a low share college graduates. In contrast, the number of entrants from industries which do not have TRI reporters is negatively related to the percent of nonwhite residents in a tract. Firms in these non-reporting industries are also more likely to enter areas with a high share of college graduates. Polluters appear to agglomerate, raising concerns about both chemical releases being concentrated in certain tracts and also affecting nonwhite-dense areas disproportionately. The strength of these effects often depend on an urban/rural classification, with rural areas experiencing the most pronounced concerns. Moreover, TRI-reporting firms are less likely to exit the market relative to their peers which operate in the same industry but do not need to file TRI reports, suggesting releases may affect a region in the long-run

Desarrollo de estructura analítica para la calificación y certificación de sustentabilidad en arquitectura

Este trabajo presenta el desarrollo y contenidos de una estructura de asesoramiento y soporte a la calificación y certificación de sustentabilidad en el diseño arquitectónico. El objetivo de dicha estructura es proporcionar conceptos básicos y pautas específicas en el desarrollo de proyectos de arquitectura sustentable, así como elaborar su inserción en la propuesta académica a implementar en los talleres de la Carrera de Arquitectura. A tal fin, el trabajo presenta una introducción en los conceptos y criterios de sustentabilidad, aspectos de innovación en la producción de hábitat construido sustentable, verificación de rubros específicos según etapas y su integración en el proceso de desarrollo de proyectos de arquitectura. Se presenta una síntesis de los rubros clave para la calificación y acreditación de sustentabilidad en arquitectura.This paper presents the development and contents of an assessment and support structure to promote the qualification and certification of sustainability in architectural design. The object of this structure is to provide basic concepts and specific guidelines for the development of sustainable architecture projects, as well as prepare the insertion in the academic proposal to be implemented in the design studios of architectural courses. With this aim, the paper presents an introduction to sustainable concepts and criteria, project innovation in the production of sustainable built environment and specific verification requirements, according to project stages and integration. The paper includes a synthesis the key aspects of qualification and accreditation of sustainability in architecture.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Desarrollo de estructura analítica para la calificación y certificación de sustentabilidad en arquitectura

Este trabajo presenta el desarrollo y contenidos de una estructura de asesoramiento y soporte a la calificación y certificación de sustentabilidad en el diseño arquitectónico. El objetivo de dicha estructura es proporcionar conceptos básicos y pautas específicas en el desarrollo de proyectos de arquitectura sustentable, así como elaborar su inserción en la propuesta académica a implementar en los talleres de la Carrera de Arquitectura. A tal fin, el trabajo presenta una introducción en los conceptos y criterios de sustentabilidad, aspectos de innovación en la producción de hábitat construido sustentable, verificación de rubros específicos según etapas y su integración en el proceso de desarrollo de proyectos de arquitectura. Se presenta una síntesis de los rubros clave para la calificación y acreditación de sustentabilidad en arquitectura.This paper presents the development and contents of an assessment and support structure to promote the qualification and certification of sustainability in architectural design. The object of this structure is to provide basic concepts and specific guidelines for the development of sustainable architecture projects, as well as prepare the insertion in the academic proposal to be implemented in the design studios of architectural courses. With this aim, the paper presents an introduction to sustainable concepts and criteria, project innovation in the production of sustainable built environment and specific verification requirements, according to project stages and integration. The paper includes a synthesis the key aspects of qualification and accreditation of sustainability in architecture.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES