2,548 research outputs found
A Rational Expectations Model for Simulation and Policy Evaluation of the Spanish Economy
This paper describes a Rational Expectations Model of the Spanish economy, REMS, which is in the tradition of small open economy dynamic general equilibrium models, with a strongly microfounded system of equations. The model is built on standard elements, but incorporates some distinctive features to provide an accurate description of the Spanish economy. We contribute to the existing models of the Spanish economy by adding search and matching rigidities to a small open economy framework. Our model also incorporates habits in consumption and rule-of-thumb households. As Spain is a member of EMU, we model the interaction between a small open economy and monetary policy in a monetary union. The model is primarily constructed to serve as a simulation tool at the Spanish Ministry of Economic Affairs and Finance. As such, it provides a great deal of information regarding the transmission of policy shocks to economic outcomes. The paper describes the structure of the model in detail, as well as the estimation and calibration technique and some examples of simulations.general equilibrium, rigidities, policy simulations
The REMSDB Macroeconomic Database of The Spanish Economy
This paper presents a new macroeconomic database for the Spanish economy, REMSDB. The construction of this database has been oriented to conducting medium-term simulations for policy evaluation with the REMS model, a large Rational Expectations macroeconomic Model for Spain. The paper provides a detailed description of the data and documents its main statistical properties. The database is thought to be of major interest to related applications,whether strictly associated with the REMS model or, rather, with empirical macroeconomic studies.Spanish Data, Growth Data, Business Cycle Data, REMS
Approximate parametrization of plane algebraic curves by linear systems of curves
t is well known that an irreducible algebraic curve is rational (i.e. parametric) if and only if its genus is zero. In this paper, given a tolerance Ï”>0 and an Ï”-irreducible algebraic affine plane curve C of proper degree d, we introduce the notion of Ï”-rationality, and we provide an algorithm to parametrize approximately affine Ï”-rational plane curves by means of linear systems of (dâ2)-degree curves. The algorithm outputs a rational parametrization of a rational curve of degree d which has the same points at infinity as C. Moreover, although we do not provide a theoretical analysis, our empirical analysis shows that and C are close in practice
Generation of a porous scaffold with a starting composition in the CaO-SiO2-MgO-P2O5 system in a simulated physiological environment
Magnesium-based ceramics are involved in orthopedic applications such as bone scaffolds or implant coatings. They provide structural support to cells for bone ingrowth, but highly porous matrices cannot resist severe mechanical stress during implantation. In this study, the laser floating zone (LFZ) technique is used to prepare a dense crystalline material with composition in the CaO-SiO2-MgO-P2O5 system. This material, under physiological conditions, is able to generate a porous scaffold controlled by the dissolution of the MgO phase, meeting the mechanical advantages of a dense material and the biological features of a porous scaffold. FESEM (Field emission scanning electron microscopy), XRD (X-ray Diffraction), EDS (Energy Dispersive X-rays spectroscopy), and ICP ((Inductively Coupled Plasma) analysis were carried out in order to characterize the samples before and after immersion in simulated body fluid (SBF)
A dark energy multiverse
We present cosmic solutions corresponding to universes filled with dark and
phantom energy, all having a negative cosmological constant. All such solutions
contain infinite singularities, successively and equally distributed along
time, which can be either big bang/crunchs or big rips singularities.
Classicaly these solutions can be regarded as associated with multiverse
scenarios, being those corresponding to phantom energy that may describe the
current accelerating universe
Quantum Conductance Steps in Solutions of Multiwalled Carbon Nanotubes
We have prepared solutions of multiwalled carbon nanotubes in Aroclor 1254, a
mixture of polychlorinated biphenyls. The solutions are stable at room
temperature. Transport measurements were performed using a scanning--tunneling
probe on a sample prepared by spin--coating of the solution on gold substrates.
Conductance steps were clearly seen. An histogram of a high number of traces
shows maximum peaks at integer values of the conductance quantum , demonstrating ballistic transport at room temperature along the carbon
nanotube over distances longer than .Comment: 4 pages and 2 figure
CaracterizaciĂłn quĂmica y cuantificaciĂłn del rendimiento de extracciĂłn de pigmento en siete accesiones mexicanas de Bixa orellana
Achiote (Bixa orellana) is a plant used for obtaining a natural dye rich on carotenoids (mainly bixin and norbixin); it is also the plant species with the highest content of tocotrienols in nature. In the present work, the pigment extraction yield of seven Mexican accessions of Bixa orellana was quantified. Also color parameters and content of tocotrienols, tocopherols, norbixin, bixin, total phenolic compounds and antioxidant capacity were evaluated in the corresponding annatto extracts. The highest percentage of pigment extraction yield was obtained with KOH (4.84%). Accessions 43 (L*= 4.01 ± 0.79, C*= 7.33 ± 1.07, h= 25.76 ± 6.35) and 50 (L*= 3.17 ± 0.64, C*= 6.81 ± 0.53, h= 26.41 ± 4.41) had the lowest color values, meaning these accessions had a darker and redder color. Four accessions showed the highest content of bixin: accession 48 (3.1%), 45 (2.6%) 43 (2.4%) and 47 (2.2%). Accession 50 had showed the highest content of total phenolic compounds and of tocotrienols (T3), mainly the isoform ÎŽ-T3 (5.03 ± 0.64 mg gâ1 Seed Dry Weight), as well as the highest antioxidant capacity.El achiote (Bixa orellana) es una planta utilizada para obtener un colorante natural rico en carotenoides (principalmente bixina y norbixina); ademĂĄs, es la especie vegetal con el mayor contenido de tocotrienoles. En este trabajo, se determinĂł el rendimiento de extracciĂłn de pigmento de siete accesiones mexicanas de Bixa orellana. TambiĂ©n se evaluaron los parĂĄmetros de color y el contenido de tocotrienoles, tocoferoles, norbixina, bixina, compuestos fenĂłlicos totales y la capacidad antioxidante en extractos de annato. El mayor porcentaje de rendimiento de extracciĂłn de pigmento fue obtenido con KOH (4.847905%). Las accesiones 43 (L*= 4.01 ± 0.79, C*= 7.33 ± 1.07, h= 25.76 ± 6.35) y 50 (L*= 3.17 ± 0.64, C*= 6.81 ± 0.53, h= 26.41 ± 4.41) presentaron los valores mĂĄs bajos de los pĂĄrametros de color, lo que significa que estas accesiones tuvieron un color mĂĄs oscuro y mĂĄs rojo. Cuatro accesiones mostraron el mayor contenido de bixina: accesiĂłn 48 (3.1%), 45 (2.6%) 43 (2.4%) and 47 (2.2%). La accession 50 mostrĂł el mayor contenido de compuestos fenĂłlicos totales y de tocotrienoles (T3), principalmente la isoforma ÎŽ-T3 (5.03 ± 0.64 mg g-1 Peso Seco), asĂ como tambiĂ©n la mayor capacidad antioxidante.Fil: Raddatz Mota, D.. Universidad AutĂłnoma Metropolitana; MĂ©xicoFil: PĂ©rez Flores, L. J.. Universidad AutĂłnoma Metropolitana; MĂ©xicoFil: Carrari, Fernando Oscar. Instituto Nacional de TecnologĂa Agropecuaria. Centro de InvestigaciĂłn en Ciencias Veterinarias y AgronĂłmicas. Instituto de BiotecnologĂa; ArgentinaFil: Insani, Ester Marina. Instituto Nacional de TecnologĂa Agropecuaria. Centro de InvestigaciĂłn en Ciencias Veterinarias y AgronĂłmicas. Instituto de BiotecnologĂa; ArgentinaFil: Asis, RamĂłn. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico CĂłrdoba. Centro de Investigaciones en BioquĂmica ClĂnica e InmunologĂa; ArgentinaFil: Mendoza Espinoza, J. A.. Universidad Nacional AutĂłnoma de MĂ©xico; MĂ©xicoFil: DĂaz de LeĂłn SĂĄnchez, F.. Universidad AutĂłnoma Metropolitana; MĂ©xicoFil: Rivera Cabrera, F.. Universidad AutĂłnoma Metropolitana; MĂ©xic
Ballistic resistivity in aluminum nanocontacts
One of the major industrial challenges is to profit from some fascinating
physical features present at the nanoscale. The production of dissipationless
nanoswitches (or nanocontacts) is one of such attractive applications.
Nevertheless, the lack of knowledge of the real efficiency of electronic
ballistic/non dissipative transport limits future innovations. For multi-valent
metallic nanosystems -where several transport channels per atom are involved-
the only experimental technique available for statistical transport
characterization is the conductance histogram. Unfortunately its interpretation
is difficult because transport and mechanical properties are intrinsically
interlaced. We perform a representative series of semiclassical molecular
dynamics simulations of aluminum nanocontact breakages, coupled to full quantum
conductance calculations, and put in evidence a linear relationship between the
conductance and the contact minimum cross-section for the geometrically favored
aluminum nanocontact configurations. Valid in a broad range of conductance
values, such relation allows the definition of a transport parameter for
nanomaterials, that represents the novel concept of ballistic resistivity
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