First principles study of adsorbed Cu_n (n=1-4) microclusters on MgO(100): structural and electronic properties

We present a density functional study of the structural and electronic properties of small Cu_n (n=1,4) aggregates on defect-free MgO(100). The calculations employ a slab geometry with periodic boundary conditions, supercells with up to 76 atoms, and include full relaxation of the surface layer and of all adsorbed atoms. The preferred adsorption site for a single Cu adatom is on top of an oxygen atom. The adsorption energy and Cu-O distance are E_S-A = 0.99 eV and d_S-A = 2.04 Angstroems using the Perdew-Wang gradient corrected exchange correlation functional. The saddle point for surface diffusion is at the "hollow" site, with a diffusion barrier of around 0.45 eV. For the adsorbed copper dimer, two geometries, one parallel and one perpendicular to the surface, are very close in energy. For the adsorbed Cu_3, a linear configuration is preferred to the triangular geometry. As for the tetramer, the most stable adsorbed geometry for Cu_4 is a rhombus. The adsorption energy per Cu atom decreases with increasing the size of the cluster, while the Cu-Cu cohesive energy increases, rapidly becoming more important than the adsorption energy.Comment: Major revision, Latex(2e) document, 23 pages, 11 figures, accepted for publication in J. of Chem. Phys., paper available at http://irrmawww.epfl.ch/vm/vm_wor

Sensitivity of Equivalent Circuits on the Extraction Procedure

The present paper proposes an approach to evaluate the “quality” of equivalent circuits of complex devices obtained by a novel technique based on constitutive sub circuits and an Particle Swarm Optimization. In particular the robustness of the obtained circuits is evaluated by a sensitivity analysis, which leads to the identification of the range of variation of its frequency response, since different runs of the global extraction procedure lead to slightly different equivalent circuits (yet topologically coincident). The analysis of the numerical results give an insight on the robustness of as single case and at the same time attest the efficiency of the extraction technique

Lymphocyte Subsets and Inflammatory Cytokines of Monoclonal Gammopathy of Undetermined Significance and Multiple Myeloma

Almost all multiple myeloma (MM) cases have been demonstrated to be linked to earlier monoclonal gammopathy of undetermined significance (MGUS). Nevertheless, there are no identified characteristics in the diagnosis of MGUS that have been helpful in differentiating subjects whose cancer may progress to a malignant situation. Regarding malignancy, the role of lymphocyte subsets and cytokines at the beginning of neoplastic diseases is now incontestable. In this review, we have concentrated our attention on the equilibrium between the diverse lymphocyte subsets and the cytokine system and summarized the current state of knowledge, providing an overview of the condition of the entire system in MGUS and MM. In an age where the therapy of neoplastic monoclonal gammopathies largely relies on drugs capable of acting on the immune system (immunomodulants, immunological checkpoint inhibitors, CAR-T), detailed knowledge of the the differences existing in benign and neoplastic forms of gammopathy is the main foundation for the adequate and optimal use of new drugs

Numerical 3D simulation of a full system air core compulsator-electromagnetic rail launcher

Multiphysics problems represent an open issue in numerical modeling. Electromagnetic launchers represent typical examples that require a strongly coupled magnetoquasistatic and mechanical approach. This is mainly due to the high velocities which make comparable the electrical and the mechanical response times. The analysis of interacting devices (e.g., a rail launcher and its feeding generator) adds further complexity, since in this context the substitution of one device with an electric circuit does not guarantee the accuracy of the analysis. A simultaneous full 3D electromechanical analysis of the interacting devices is often required. In this paper a numerical 3D analysis of a full launch system, composed by an air-core compulsator which feeds an electromagnetic rail launcher, is presented. The analysis has been performed by using a dedicated, in-house developed research code, named "EN4EM" (Equivalent Network for Electromagnetic Modeling). This code is able to take into account all the relevant electromechanical quantities and phenomena (i.e., eddy currents, velocity skin effect, sliding contacts) in both the devices. A weakly coupled analysis, based on the use of a zero-dimensional model of the launcher (i.e., a single loop electrical equivalent circuit), has been also performed. Its results, compared with those by the simultaneous 3D analysis of interacting devices, show an over-estimate of about 10-15% of the muzzle speed of the armature

Null-Flux Coils in Permanent Magnets Bearings

In this paper, the stability analysis of a new permanent magnets (PMs) bearings is presented and discussed. The suspension is assured by the repulsive force of properly shaped PMs placed on both the stator and the rotor. Then, exploiting currents induced on a system of null-flux coils attached to the stator, a stabilizing force for the translation of the center of mass of the rotor is obtained. The performance of the proposed bearing is investigated by a research code, previously developed at DESTEC and capable to simulate six degrees of freedom electromechanical devices

Residential Location, Mobility, and Travel Time: A Pilot Study in a Small-Size Italian Metropolitan Area

This research concerns the topic of Land Use and Transport Interaction (LUTI) models. In particular, the patterns between residential households' location and mobility choices are analyzed and simulated. The attributes that influence household residential location choices belong to four categories: socioeconomic and mobility attributes of households and/or of their components; land use; real-estate market; transport system. The paper presents the results of a pilot study on households' location and mobility patterns in the metropolitan area of Reggio Calabria (Southern Italy). The pilot study is divided into two stages. In the first stage, a survey allowed to collect information and identify existing patterns about residential and mobility choices of a sample of households. In the second stage, a residential location model is proposed and some preliminary calibrations are presented in a prototypal way. The pilot study could be extended and improved in terms of spatial extension and sample dimension in order to allow a complete specification-calibration-validation process of the model. The model development can support the land use-transport planning process in the Metropolitan City of Reggio Calabria

Mapping the danger to life in flash flood events adopting a mechanics based methodology and planning evacuation routes

Extreme flood events are becoming more frequent and challenging due to climate change. Key objectives of this study are to evaluate different criteria used in assessing the hazard to people during flood events and, once determined, the most suitable method is then used to assess the hazard and the safest route(s) for evacuation during a flood event and for a particular case study. The results of the application of two criteria are analysed in terms of the flood hazard assessment with the two criteria being based on a widely used empirical approach and a mechanics based approach. Both criteria are used to assess the flood hazard to people during an extreme flash flood, which occurred on 16th August 2004 in Boscastle (UK). Results obtained for this study have highlighted that the mechanics based criteria are preferable in identifying the ideal escape routes, when considering the flood characteristics and the corresponding response of a human body. The main novelty of this study lies in linking the flood hazard rating with the human body characteristics, when determining the safest route and with a revised formula being developed, which includes the effects of ground slope in the application to a real case study

Intracranial hematopoiesis in a patient with aids-related central nervous system lymphoma and severe pancytopenia

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