Clumpy Disc and Bulge Formation

We present a set of hydrodynamical/Nbody controlled simulations of isolated gas rich galaxies that self-consistently include SN feedback and a detailed chemical evolution model, both tested in cosmological simulations. The initial conditions are motivated by the observed star forming galaxies at z ~ 2-3. We find that the presence of a multiphase interstellar media in our models promotes the growth of disc instability favouring the formation of clumps which in general, are not easily disrupted on timescales compared to the migration time. We show that stellar clumps migrate towards the central region and contribute to form a classical-like bulge with a Sersic index, n > 2. Our physically-motivated Supernova feedback has a mild influence on clump survival and evolution, partially limiting the mass growth of clumps as the energy released per Supernova event is increased, with the consequent flattening of the bulge profile. This regulation does not prevent the building of a classical-like bulge even for the most energetic feedback tested. Our Supernova feedback model is able to establish a self-regulated star formation, producing mass-loaded outflows and stellar age spreads comparable to observations. We find that the bulge formation by clumps may coexit with other channels of bulge assembly such as bar and mergers. Our results suggest that galactic bulges could be interpreted as composite systems with structural components and stellar populations storing archaeological information of the dynamical history of their galaxy.Comment: Accepted for publication in MNRAS - Aug. 20, 201

Polymer chain generation for coarse-grained models using radical-like polymerization

An innovative method is proposed to generate configurations of coarse grained models for polymer melts. This method, largely inspired by chemical ``radical polymerization'', is divided in three stages: (i) nucleation of radicals (reacting molecules caching monomers); (ii) growth of chains within a solvent of monomers; (iii) termination: annihilation of radicals and removal of residual monomers. The main interest of this method is that relaxation is performed as chains are generated. Pure mono and poly-disperse polymers melts are generated and compared to the configurations generated by the Push Off method from Auhl et al.. A detailed study of the static properties (gyration radius, mean square internal distance, entanglement length) confirms that the radical-like polymerization technics is suitable to generate equilibrated melts. The method is flexible, and can be adapted to generate nano-structured polymers, namely diblock and triblock copolymers.Comment: 9 pages, 12 figure

The Diversity of Design of TSOs

International audienceIt is puzzling today to explain diversity and imperfection of actual transmission monopoly designs in competitive electricity markets. We argue that transmission monopoly in competitive electricity markets has to be analysed within a Wilson (2002) modular framework. Applied to the management of electricity flows, at least three modules make the core of transmission design: 1° the short run management of network externalities; 2° the long run management of network investment; and 3° the coordination of neighboring Transmission System Operators for cross border trade. In order to tackle this diversity of designs of TSOs, we show that for each of these modules, three different basic ways of managing them are possible. Among the identified twenty seven options of organisation, we define an Ideal TSO. Second, we demonstrate that 1°monopoly design differs from this Ideal TSO and cannot handle these three modules irrespective of the “institutional” definition and allocation of property rights on transmission; while 2°definition and allocation of property rights on transmission cannot ignore the existing electrical industry and transmission network structure: they have to complement each other to be efficient. Some conclusions for regulatory issues of transmission systems operators are derived from this analysis of network monopoly organisation

Precipitation of niobium carbonitrides in ferrite: chemical composition measurements and thermodynamic modelling

High-resolution transmission electron microscopy and electron-energy loss spectroscopy have been used to characterize the structure and chemical composition of niobium carbonitrides in the ferrite of a Fe–Nb–C–N model alloy at different precipitation stages. Experiments seem to indicate the coexistence of two types of precipitates: pure niobium nitrides and mixed substoichiometric niobium carbonitrides. In order to understand the chemical composition of these precipitates, a thermodynamic formalism has been developed to evaluate the nucleation and growth rates (classical nucleation theory) and the chemical composition of nuclei and existing precipitates. A model based on the numerical solution of thermodynamic and kinetic equations is used to compute the evolution of the precipitate size distribution at a given temperature. The predicted compositions are in very good agreement with experimental results

Exploring the Acculturation Experiences of Cuban Refugee Doctors and their Families in Miami: A Phenomenological Study

Since 1961, the Cuban government has used its medical missions worldwide for diplomatic, ideological, financial, and humanitarian purposes (Huish, 2014; Solano, 2019). Since the collapse of the Socialist Bloc, thousands of Cuban health workers have found a means of economic subsistence and exit from the island through these missions. The U.S. Department of State (2020) declared these medical missions to be forced labor and human trafficking, a move that had multiple consequences for these professionals and their families. From 2006 to 2017, more than 9,000 Cuban health workers entered the Unites States as refugee immigrants, with many settling in South Florida (Solidarity Without Borders, 2019). These doctors and families have experienced acculturation stress and substantial change intheir cultural identifications, practices, and values. Existing research has focused on individual perspectives, leaving a significant gap in the literature on theacculturation process from a family and systemic perspective. This study, using an Interpretative Phenomenological Analysis (IPA) design, explored the lived experiences of acculturation of five Cuban refugee doctors and a member of each doctor’s family. Research themes indicated that for these immigrants, thefamily was the main motivation to undertake their migratory and acculturation process. In the midst of separations and stressful situations, participants preserved the family unit and valued the decision to immigrate. Findings suggested that these Cuban immigrants and their families have developed flexible bicultural pathways, actively integrating and discarding components of both cultures in order to facilitate integration in Miami. Based on the results, the researcher presents implications of the study for family therapists working with this population and pathways for future research

The role of transmission investment in the coordination between generation and transmission in the liberalized power systems

This paper examines how transmission coordinates with generation to the long term in a liberalized power system. We rely on a modular analysis to separate the mechanisms of coordination between generation and transmission of electricity into distinct modules. The governance structure of transmission completes this analysis framework. We then show that in a logic of complementarity, this governance structure influences the options that TSO implements to manage effectively power flows. Although locational signals are necessary to guide the installation of new power plants, the governance structure explains that investment in network may be the only effective method of longterm coordination between generation and transmission.The diversity of design of TSOs

Anticipation for Efficient Electricity Transmission Network Investments

This paper proposes a model and preliminary results to evaluate the efficiency of anticipating the connection of power plants with shorter construction duration than the time needed to obtain the right to upgrade the network and finally to do this reinforcement. This evaluation is made in presence of a cost of anticipation related to the study of the project of network investment and to the administrative procedures needed to obtain the building agreement. This model compares a proactive TSO that anticipates the connection of new generators and then the required network reinforcement, with a reactive one that does not make any anticipation but that may then face greater congestion while the network is being reinforced. The efficiency of these behaviors is measured in terms of social cost. We find out that there exists a limit of probability for the connection of generators beyond which a proactive TSO is more efficient than a reactive one. Evaluated on a realistic case of connection, this limit of probability is found quite low, which indicates that the proactive behavior for a TSO shall generally be the optimal one.

The role of transmission investment in the coordination between generation and transmission in the liberalized power systems

This paper examines how transmission coordinates with generation to the long term in a liberalized power system. We rely on a modular analysis to separate the mechanisms of coordination between generation and transmission of electricity into distinct modules. The governance structure of transmission completes this analysis framework. We then show that in a logic of complementarity, this governance structure influences the options that TSO implements to manage effectively power flows. Although locational signals are necessary to guide the installation of new power plants, the governance structure explains that investment in network may be the only effective method of longterm coordination between generation and transmission.

Computation of topological phase diagram of disordered Pb1−x_{1-x}Snx_{x}Te using the kernel polynomial method

We present an algorithm to determine topological invariants of inhomogeneous systems, such as alloys, disordered crystals, or amorphous systems. Based on the kernel polynomial method, our algorithm allows us to study samples with more than $10^7$ degrees of freedom. Our method enables the study of large complex compounds, where disorder is inherent to the system. We use it to analyse Pb$_{1-x}$Sn$_{x}$Te and tighten the critical concentration for the phase transition.Comment: 4 pages + supplemental materia