Firms’ growth, size and age: a nonparametric approach

This paper offers empirical evidence of firm failure rates as well as the mean of the distribution of realized growth rates, distinguishing between the sample of non-failing firms and the sample of all firms, failing and non-failing. Attention is directed at identifying a set of characteristics, in particular the size and age of firms, systematically related to the patterns of firm growth and exit, using a panel of Spanish manufacturing firms. The two main contributions of the paper are the use of nonparametric techniques and the analysis of issues ignored in other studies like the regression-to-the-mean bias and the measurement of learning effects. We find evidence that failure rates and the mean growth rate of successful firms decline with size and age. When failing firms are integrated, there are no significant differences in the mean growth rate across the age and size of firms. Regression-to-the-mean does not prove to be a substantial factor behind the negative relationship between size and growth of surviving firms

Erosión minera en la cuenca del arroyo Peñalén (Parque Natural del Alto Tajo, Guadalajara)

Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu

The Scope, Scale and Locational Preferences of Spanish Multinationals

This paper examines the relationship between firms’ heterogeneity and their multinational activity. We examine the scope and the scale of multinational firms following the insights of Yeaple’s (2009) model. The goal of the paper is to contribute to a better understanding of the activity of Spanish multinationals using a sample of Spanish multinational firms. Our dataset is built from two databases, SABI and ORBIS, both from the Bureau van Dijk. Our results confirm that more productive firms have a greater multinational activity in terms of both the scope (the number of foreign markets where they invest) and the scale (the volume of local sales by subsidiaries in foreign markets). The structure of Spanish multinational firms’ activity is also analysed from the perspective of host country characteristics (GDP, population, distance and language) using standard gravity equations. Country characteristics that are positively associated (GDP and common language) with the volume of multinational activity are negatively related to the productivity of firms that go abroad. This asymmetry also holds for bilateral characteristics as distance that appears negatively associated with the level of multinational activity

Las decisiones de localización, alcance y escala de las empresas multinacionales españolas

This research has been partially funded by the Spanish Ministry of Economy and Competitiveness (project ECO2014-52051-R and ECO2017-82445-R) and by the Autonomous Region of Madrid through project S2015HUM-3417 (INNCOMCON-CM), co-funded by the European Social Fund (European Union). The authors benefited from presentations at the 4th PhD-Student Workshop on Industrial and Public Economics (Reus, 2016), the Conference on International Economics (La Coruña, 2016) and especially from suggestions from Andrés Barge.This paper examines the relationship between firms’ heterogeneity and their multinational activity. We examine the scope and the scale of multinational firms following the insights of Yeaple’s (2009) model. The goal of the paper is to contribute to a better understanding of the activity of Spanish multinationals using a sample of Spanish multinational firms. Our dataset is built from two databases, SABI and ORBIS, both from the Bureau van Dijk. Our results confirm that more productive firms have a greater multinational activity in terms of both the scope (the number of foreign markets where they invest) and the scale (the volume of local sales by subsidiaries in foreign markets). The structure of Spanish multinational firms’ activity is also analysed from the perspective of host country characteristics (GDP, population, distance and language) using standard gravity equations. Country characteristics that are positively associated (GDP and common language) with the volume of multinational activity are negatively related to the productivity of firms that go abroad. This asymmetry also holds for bilateral characteristics as distance that appears negatively associated with the level of multinational activity.En este trabajo se analiza la relación entre la heterogeneidad de las empresas españolas y su actividad multinacional contrastando las predicciones del modelo de Yeaple (2009). Se utiliza una base de datos de empresas multinacionales españolas fusionando dos bases de datos, SABI y ORBIS. Los resultados confirman que las empresas más productivas tienen una mayor actividad multinacional tanto en términos de alcance (número de mercados extranjeros donde las empresas matrices invierten) y de escala (el volumen de las ventas de las subsidiarias en los mercados extranjeros). La estructura de la actividad de las empresas multinacionales también se analiza desde la perspectiva de las características del país receptor (PIB, población, distancia, lengua común…) usando ecuaciones de gravedad. Las características del país que están positivamente relacionadas (PIB y lengua común…) con el volumen de la actividad multinacional presentan una relación negativa con la productividad de las empresas que operan en el exterior. Este efecto asimétrico también se produce para otras variables como la distancia que está negativamente asociada con la actividad multinacional y positivamente con la productividad de las empresas multinacionales.DecanatoFac. de Ciencias Económicas y EmpresarialesTRUEMinisterio de Economía y Competitividad (MINECO)Comunidad de Madridunpu

Cycle by cycle NOx model for diesel engine control

[EN] This paper presents a model for on-line NOx estimation. The method uses both, low frequency components and high frequency components of in-cylinder pressure signal: it harnesses in-cylinder pressure resonance to estimate the trapped mass, and based on this measurement, a NOx model is adapted to estimate NOx emissions cycle by cycle. In addition of the in-cylinder pressure signal, the procedure only requires from lambda and air mass flow to estimate NOx, so it can give a direct estimation of NOx or improve transient response and aging of current NOx sensors. The method was validated on a CI engine with high pressure EGR loop under steady and transient conditions showing errors below 10% and cycle by cycle time response. (C) 2016 Elsevier Ltd. All rights reserved.Guardiola, C.; Martín, J.; Pla, B.; Bares-Moreno, P. (2017). Cycle by cycle NOx model for diesel engine control. Applied Thermal Engineering. 110:1011-1020. doi:10.1016/j.applthermaleng.2016.08.170S1011102011

Hacia una Minería Sostenible en el 95 entorno del Parque Natural del Alto Tajo. La escombrera experimental de la mina ‘El Machorro’(Poveda de la Sierra, Guadalajara)

Por su situación en el entorno de un espacio natural protegido, y sobre una ladera de pendiente y longitud elevadas, la restauración de la mina El Machorro constituye un importante reto científico y profesional. La empresa propietaria de esta mina, CAOBAR S.A., tiene entre sus objetivos demostrar la compatibilidad de la actividad minera con la conservación del medio ambiente. Por todo ello está acometiendo sucesivas revisiones de su Plan de Restauración del Espacio Natural (PREN), tratando de incorporar las mejores prácticas internacionales al respecto. Todo ello en colaboración con las universidades Complutense y de Alcalá (Madrid) y bajo la supervisión de la Dirección del Parque Natural del Alto Tajo. Una de las acciones más destacadas a ese respecto ha sido la construcción de una escombrera experimental, específicamente diseñada para mejorar la restauración de los terrenos afectados por la mina. En ella se estudia el comportamiento erosivo que tienen diferentes diseños de escombreras mediante la combinación de: (a) distintas topografías (cóncava y en terrazas); (b) distintos tipos de sustrato (estériles, coluviones y suelos originales); y (c) distintos tipos de revegetación (como hidrosiembras). En la comunicación se describen los detalles de la puesta en funcionamiento de esta escombrera experimental, así como los resultados obtenidos para el periodo 1 de noviembre de 2008 a 31 de marzo de 2009

Theory of strong coupling between quantum emitters and propagating surface plasmons

Under the terms of the Creative Commons Attribution License 3.0 (CC-BY).Here we present the theoretical foundation of the strong coupling phenomenon between quantum emitters and propagating surface plasmons observed in two-dimensional metal surfaces. For that purpose, we develop a quantum framework that accounts for the coherent coupling between emitters and surface plasmons and incorporates the presence of dissipation and dephasing. Our formalism is able to reveal the key physical mechanisms that explain the reported phenomenology and also determine the physical parameters that optimize the strong coupling. A discussion regarding the classical or quantum nature of this phenomenon is also presented. © 2013 American Physical Society.This work was supported by the Spanish MINECO (Contracts No.MAT2011-22997, No.MAT2011-28581-C02, and No. CSD2007-046-NanoLight.es) and CAM (Contract No. S-2009/ESP-1503). A. G.-T. and P. A.-H acknowledge FPU Grants No. AP2008-00101 and No. AP2008-00021, respectively, from the Spanish Ministry of Education. This work has been partially funded by the European Research Council (ERC-2011-AdG Proposal No. 290981).S-2009/ESP-1503/Q&C LIGHTPeer Reviewe

Weak and Strong coupling regimes in plasmonic-QED

We present a quantum theory for the interaction of a two level emitter with surface plasmon polaritons confined in single-mode waveguide resonators. Based on the Green's function approach, we develop the conditions for the weak and strong coupling regimes by taking into account the sources of dissipation and decoherence: radiative and non-radiative decays, internal loss processes in the emitter, as well as propagation and leakage losses of the plasmons in the resonator. The theory is supported by numerical calculations for several quantum emitters, GaAs and CdSe quantum dots and NV centers together with different types of resonators constructed of hybrid, cylindrical or wedge waveguides. We further study the role of temperature and resonator length. Assuming realistic leakage rates, we find the existence of an optimal length at which strong coupling is possible. Our calculations show that the strong coupling regime in plasmonic resonators is accessible within current technology when working at very low temperatures (<4K). In the weak coupling regime our theory accounts for recent experimental results. By further optimization we find highly enhanced spontaneous emission with Purcell factors over 1000 at room temperature for NV-centers. We finally discuss more applications for quantum nonlinear optics and plasmon-plasmon interactions.Comment: published as Phys. Rev. B 87, 115419 (2013

Saturated fat in the diet of Spanish children: relationship with anthropometric, alimentary, nutritional and lipid profiles

OBJECTIVE: To compare the anthropometric, alimentary, nutritional and lipid profiles and global diet quality of Spanish children according to saturated fat intake. DESIGN: This was a cross-sectional study. Food data were collected using a food-frequency questionnaire. SUBJECTS AND METHODS: The sample included 1112 children of both sexes, aged between 6 and 7 years, selected by means of random cluster sampling in schools. The plasma lipid profile included measurements of low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides, apolipoprotein A1 (apoA1) and apolipoprotein B (apoB). Global diet quality was evaluated by the Dietary Variety Index (DVI) and the Healthy Eating Index (HEI). RESULTS: Energy intake, DVI and HEI of children from the lower quartile of saturated fat intake (LL) were higher (P<001) than in the remaining children (UL). However, there were no significant differences in average height or weight between groups. The UL children had lower intakes of meat, fish, vegetables, fruits and olive oil and a higher intake of dairy products (P<0.001). The intakes of fibre, vitamins C, D, B6, E and folic acid were higher in the LL children, who had lower intakes of vitamin A and calcium. The ratios LDL-C/HDL-C and apoB/apoA1 were lower (P=0.04) in the LL children (1.87 and 0.52, respectively) than in the UL children (2.02 and 0.54, respectively). CONCLUSIONS: The growth rate of children does not seem to be affected by the level of saturated fat intake. Furthermore, at the levels of intake observed in this study, diets with less saturated fat are associated with better alimentary, nutritional and plasma lipid profiles.This study was partly funded by grants from the Fondo deInvestigacio ́n Sanitaria (FIS 020994, FIS02/3104) and theMinisterio Agricultura Pesca y Alimentacio ́n. We thankAlexander G Borun for manuscript revisionS

A template method to measure the tt polarisation

This work is supported by the Spanish Research Agency (Agencia Estatal de Investigacion) through the grant IFT Centro de Excelencia Severo Ochoa SEV-2016-0597, by the projects PID2019-110058GB-C21, PID2019-110058GB-C22 from MICINN/AEI/ERDF, and by projects CERN/FIS-PAR/0004/2019, CERN/FIS-PAR/0029/2019 from FCT. The work of P.M.R. is supported through the FPI grant BES-2016-076775. The work of M.C.N.F. was supported by the PSC-CUNY Awards 63096-00 51 and 64031-00 52.We develop a template method for the measurement of the polarisation of tt¯ pairs produced in hadron collisions. The method would allow to extract the individual fractions of tLt¯ L, tRt¯ R, tLt¯ R and tRt¯ L pairs with a fit to data, where L, R refer to the polarisation along any axis. These polarisation fractions have not been independently measured at present. Secondarily, the method also provides the net polarisation of t and t¯ , as well as their spin correlation for arbitrary axes.IFT Centro de Excelencia Severo Ochoa PID2019-110058GB-C21, PID2019-110058GB-C22, SEV-2016-0597PSC-CUNY 63096-00 51, 64031-00 52Spanish Research AgencyFamily Process Institute BES-2016-076775Ministerio de Ciencia e InnovaciónEuropean Regional Development Fund CERN/FIS-PAR/0004/2019, CERN/FIS-PAR/0029/2019Fundació Catalana de TrasplantamentAgencia Estatal de Investigació