The economics of child well-being

This paper presents an integrated economic approach that organizes and interprets the evidence on child development. It also discusses the indicators of child well-being that are used in international comparisons. Recent evidence on child development is summarized, and policies to promote child well-being are discussed. The chapter concludes with some open questions and suggestions for future research

Subwavelength optical spatial solitons and three-dimensional localization in disordered ferroelectrics: towards metamaterials of nonlinear origin

We predict the existence of a novel class of multidimensional light localizations in out-of-equilibrium ferroelectric crystals. In two dimensions, the non-diffracting beams form at arbitrary low power level and propagate even when their width is well below the optical wavelength. In three dimensions, a novel form of subwavelength light bullets is found. The effects emerge when compositionally disordered crystals are brought to their metastable glassy state, and can have a profound impact on super-resolved imaging and ultra-dense optical storage, while resembling many features of the so-called metamaterials, as the suppression of evanescent waves.Comment: 4 pages, 3 figure

Evaluation of thermal insulation materials

Data was obtained on silicone-bonded fiberglass, isocyanurate foam, and two dozen other insulators. Materials were selected to withstand heat sterilization, outer space, and the Martian atmosphere. Significant environmental parameters were vibration, landing shock, and launch venting

A microscopic model for solidification

We present a novel picture of a non isothermal solidification process starting from a molecular level, where the microscopic origin of the basic mechanisms and of the instabilities characterizing the approach to equilibrium is rendered more apparent than in existing approaches based on coarse grained free energy functionals \`a la Landau. The system is composed by a lattice of Potts spins, which change their state according to the stochastic dynamics proposed some time ago by Creutz. Such a method is extended to include the presence of latent heat and thermal conduction. Not only the model agrees with previous continuum treatments, but it allows to introduce in a consistent fashion the microscopic stochastic fluctuations. These play an important role in nucleating the growing solid phase in the melt. The approach is also very satisfactory from the quantitative point of view since the relevant growth regimes are fully characterized in terms of scaling exponents.Comment: 7 pages Latex +3 figures.p

On the generation and the nonlinear dynamics of X-waves of the Schroedinger equation

The generation of finite energy packets of X-waves is analysed in normally dispersive cubic media by using an X-wave expansion. The 3D nonlinear Schroedinger model is reduced to a 1D equation with anomalous dispersion. Pulse splitting and beam replenishment as observed in experiments with water and Kerr media are explained in terms of a higher order breathing soliton. The results presented also hold in periodic media and Bose-condensed gases.Comment: 18 pages, 6 figures, corrected version to be published in Physical Review

Homogenization in magnetic-shape-memory polymer composites

Magnetic-shape-memory materials (e.g. specific NiMnGa alloys) react with a large change of shape to the presence of an external magnetic field. As an alternative for the difficult to manifacture single crystal of these alloys we study composite materials in which small magnetic-shape-memory particles are embedded in a polymer matrix. The macroscopic properties of the composite depend strongly on the geometry of the microstructure and on the characteristics of the particles and the polymer. We present a variational model based on micromagnetism and elasticity, and derive via homogenization an effective macroscopic model under the assumption that the microstructure is periodic. We then study numerically the resulting cell problem, and discuss the effect of the microstructure on the macroscopic material behavior. Our results may be used to optimize the shape of the particles and the microstructure.Comment: 17 pages, 4 figure

The RD53 Collaboration's SystemVerilog-UVM Simulation Framework and its General Applicability to Design of Advanced Pixel Readout Chips

The foreseen Phase 2 pixel upgrades at the LHC have very challenging requirements for the design of hybrid pixel readout chips. A versatile pixel simulation platform is as an essential development tool for the design, verification and optimization of both the system architecture and the pixel chip building blocks (Intellectual Properties, IPs). This work is focused on the implemented simulation and verification environment named VEPIX53, built using the SystemVerilog language and the Universal Verification Methodology (UVM) class library in the framework of the RD53 Collaboration. The environment supports pixel chips at different levels of description: its reusable components feature the generation of different classes of parameterized input hits to the pixel matrix, monitoring of pixel chip inputs and outputs, conformity checks between predicted and actual outputs and collection of statistics on system performance. The environment has been tested performing a study of shared architectures of the trigger latency buffering section of pixel chips. A fully shared architecture and a distributed one have been described at behavioral level and simulated; the resulting memory occupancy statistics and hit loss rates have subsequently been compared.Comment: 15 pages, 10 figures (11 figure files), submitted to Journal of Instrumentatio

Linearons: highly non-instantaneous solitons in liquid-core photonic crystal fibers

The nonlinear propagation of light pulses in liquid-filled photonic crystal fibers is considered. Due to the slow reorientational nonlinearity of some molecular liquids, the nonlinear modes propagating inside such structures can be approximated, for pulse durations much shorter than the molecular relaxation time, by temporally highly-nonlocal solitons, analytical solutions of a linear Schroedinger equation. The physical relevance of these novel solitary structures, which may have a broad range of applications, is discussed and supported by detailed numerical simulations.Comment: 4 pages, 3 figure

The Jurassic pleurotomarioidean gastropod Laevitomaria and its palaeobiogeographical history

The genus Laevitomaria is reviewed and its palaeobiogeographical history is reconstructed based on the re-examination of its type species L. problematica, the study of material stored at the National Natural History Museum of Luxembourg, and an extensive review of the literature. The systematic study allows ascribing to Laevitomaria a number of Jurassic species from the western European region formerly included in other pleurotomariid genera. The following new combinations are proposed: Laevitomaria allionta, Laevitomaria amyntas, Laevitomaria angulba, Laevitomaria asurai, Laevitomaria daityai, Laevitomaria fasciata, Laevitomaria gyroplata, Laevitomaria isarensis, Laevitomaria joannis, Laevitomaria repeliniana, Laevitomaria stoddarti, Laevitomaria subplatyspira, and Laevitomaria zonata. The genus, which was once considered as endemic of the central part of the western Tethys, shows an evolutionary and palaeogeographical history considerably more complex than previously assumed. It first appeared in the Late Sinemurian in the northern belt of the central western Tethys involved in the Neotethyan rifting, where it experienced a first radiation followed by an abrupt decline of diversity in the Toarcian. Species diversity increased again during Toarcian\u2013Aalenian times in the southernmost part of western European shelf and a major radiation occurred during the Middle Aalenian to Early Bajocian in the northern Paris Basin and southern England. After a latest Bajocian collapse of diversity, Laevitomaria disappeared from both the central part of western Tethys and the European shelf. In the Bathonian, the genus appeared in the south-eastern margin of the Tethys where it lasted until the Oxfordian