7,130 research outputs found

    Review on bibliography related to antimicrobials

    Get PDF
    In this report, a bibliographic research has been done in the field of antimicrobials.In this report, a bibliographic research has been done in the field of antimicrobials. Not all antimicrobials have been included, but those that are being subject of matter in the group GBMI in Terrassa, and others of interest. It includes chitosan and other biopolymers. The effect of nanoparticles is of great interest, and in this sense, the effect of Ag nanoparticles and antibiotic nanoparticles (nanobiotics) has been revised. The report focuses on new publications and the antimicrobial effect of peptides has been considered. In particular, the influence of antimicrobials on membranes has deserved much attention and its study using the Langmuir technique, which is of great utility on biomimetic studies. The building up of antimicrobials systems with new techniques (bottom-up approach), as the Layer-by-Layer technique, can also be found in between the bibliography. It has also been considered the antibiofilm effect, and the new ideas on quorem sensing and quorum quenching.Preprin

    Parallel eigensolvers in plane-wave Density Functional Theory

    Full text link
    We consider the problem of parallelizing electronic structure computations in plane-wave Density Functional Theory. Because of the limited scalability of Fourier transforms, parallelism has to be found at the eigensolver level. We show how a recently proposed algorithm based on Chebyshev polynomials can scale into the tens of thousands of processors, outperforming block conjugate gradient algorithms for large computations

    Multiple Scattering Formulation of Two Dimensional Acoustic and Electromagnetic Metamaterials

    Full text link
    This work presents a multiple scattering formulation of two dimensional acoustic metamaterials. It is shown that in the low frequency limit multiple scattering allows us to define frequency-dependent effective acoustic parameters for arrays of both ordered and disordered cylinders. This formulation can lead to both positive and negative acoustic parameters, where the acoustic parameters are the scalar bulk modulus and the tensorial mass density and, therefore, anisotropic wave propagation is allowed with both positive or negative refraction index. It is also shown that the surface fields on the scatterer are the main responsible of the anomalous behavior of the effective medium, therefore complex scatterers can be used to engineer the frequency response of the effective medium, and some examples of application to different scatterers are given. Finally, the theory is extended to electromagnetic wave propagation, where Mie resonances are found to be the responsible of the metamaterial behavior. As an application, it is shown that it is possible to obtain metamaterials with negative permeability and permittivity tensors by arrays of all-dielectric cylinders and that anisotropic cylinders can tune the frequency response of these resonances

    New human resource management systems in non-based-knowledge firms: Applications for decision making on the business performance

    Get PDF
    The aim of this paper is double. First, it provides a conceptual framework and modelling of the relationship between human resource management (HRM) systems and non-based-knowledge firms. Second, using survey data on 1.518 Catalan firms (in Spain, with capital in Barcelona), the paper: 1) identify two system of HRM (in progress HRM system and non-HRM developed system); 2) build a causal model of determinants of HRM systems; and 3) describe the association links between in progress HRM system and firm's performance. Using factor and cluster analysis, we find that only one-third of firms use in progress HRM system. Using logit binomial analysis, we find that features which are structural, technological, strategic, organisational and performance-related explain the adoption of in progress HRM system. Finally, using association analysis, we find that firms that adopt in progress HRM system: 1) are more internationalised and show greater ability to adapt to the changing environment, to innovate and to collaborate; 2) focus on product/service differentiation strategy enhancing quality; 3) apply a greater degree of new forms of work organization; 4) have more technological equipment and use IT more intensively; and 5) invest more in training their employees, than firms with non-HRM system developed

    Using problem-based learning for introducing producer theory and market structure in intermediate microeconomics

    Get PDF
    This paper shows how instructors can use the problem-based learning method to introduce producer theory and market structure in intermediate microeconomics courses. The paper proposes a framework where different decision problems are presented to students, who are asked to imagine that they are the managers of a firm who need to solve a problem in a particular business setting. In this setting, the instructors’ role is to provide both guidance to facilitate student learning and content knowledge on a just-in-time basis.

    A new approach to local hardness

    Full text link
    The applicability of the local hardness as defined by the derivative of the chemical potential with respect to the electron density is undermined by an essential ambiguity arising from this definition. Further, the local quantity defined in this way does not integrate to the (global) hardness - in contrast with the local softness, which integrates to the softness. It has also been shown recently that with the conventional formulae, the largest values of local hardness do not necessarily correspond to the hardest regions of a molecule. Here, in an attempt to fix these drawbacks, we propose a new approach to define and evaluate the local hardness. We define a local chemical potential, utilizing the fact that the chemical potential emerges as the additive constant term in the number-conserving functional derivative of the energy density functional. Then, differentiation of this local chemical potential with respect to the number of electrons leads to a local hardness that integrates to the hardness, and possesses a favourable property; namely, within any given electron system, it is in a local inverse relation with the Fukui function, which is known to be a proper indicator of local softness in the case of soft systems. Numerical tests for a few selected molecules and a detailed analysis, comparing the new definition of local hardness with the previous ones, show promising results.Comment: 30 pages (including 6 figures, 1 table
    • …
    corecore