Atmospheric corrosion of quaternary bronzes (Cu-Sn-Zn-Pb): laboratory tests (accelerated ageing in wet & dry conditions)and field studies (the Bottego monument in Parma, Italy).

The interactions between outdoor bronzes and the environment, which lead to bronze corrosion, require a better understanding in order to design effective conservation strategies in the Cultural Heritage field. In the present work, investigations on real patinas of the outdoor monument to Vittorio Bottego (Parma, Italy) and laboratory studies on accelerated corrosion testing of inhibited (by silane-based films, with and without ceria nanoparticles) and non-inhibited quaternary bronzes are reported and discussed. In particular, a wet&dry ageing method was used both for testing the efficiency of the inhibitor and for patinating bronze coupons before applying the inhibitor. A wide range of spectroscopic techniques has been used, for characterizing the core metal (SEM+EDS, XRF, AAS), the corroded surfaces (SEM+EDS, portable XRF, micro-Raman, ATR-IR, Py-GC-MS) and the ageing solutions (AAS). The main conclusions were: 1. The investigations on the Bottego monument confirmed the differentiation of the corrosion products as a function of the exposure geometry, already observed in previous works, further highlighting the need to take into account the different surface features when selecting conservation procedures such as the application of inhibitors (i.e. the relative Sn enrichment in unsheltered areas requires inhibitors which effectively interact not only with Cu but also with Sn). 2. The ageing (pre-patination) cycle on coupons was able to reproduce the relative Sn enrichment that actually happens in real patinated surfaces, making the bronze specimens representative of the real support for bronze inhibitors. 3. The non-toxic silane-based inhibitors display a good protective efficiency towards pre-patinated surfaces, differently from other widely used inhibitors such as benzotriazole (BTA) and its derivatives. 4. The 3-mercapto-propyl-trimethoxy-silane (PropS-SH) additivated with CeO2 nanoparticles generally offered a better corrosion protection than PropS-SH

Optimizing Scan Homogeneity for Building Full-3D Lidars based on Rotating a Multi-Beam Velodyne Rangefinder

Multi-beam lidar (MBL) scanners are compact, light, and accessible 3D sensors with high data rates, but they offer limited vertical resolution and field of view (FOV). Some recent robotics research has profited from the addition of a degree-of-freedom (DOF) to an MBL to build rotating multi-beam lidars (RMBL) that can achieve high-resolution scans with full spherical FOV. In a previous work, we offered a methodology to analyze the complex 3D scan measurement distributions produced by RMBLs with a rolling DOF and no pitching. In this paper, we investigate the effect of introducing constant pitch angles in the construction of the RMBLs with the purpose of finding a kinematic configuration that optimizes scan homogeneity with a spherical FOV. To this end, we propose a scalar index of 3D sensor homogeneity that is based on the spherical formulation of Ripley's K function. The optimization is performed for the widely used Puck (VLP-16) and HDL-32 sensors by Velodyne.This work was partially funded by the Spanish project {DPI2015-65186-R}. The publication has received support from Universidad de Málaga, Campus de Excelencia Andalucía Tech

Aerodynamics measurements in a wind tunnel

2018/201

Early Cretaceous absolute geomagnetic paleointensities from Córdoba province (Argentina)

We present here new paleointensity and geochronology results from Early Cretaceous volcanic rocks of Sierra Chica de Cordoba (Argentina). The new K-Ar isotopic ages of 5 samples range from 136 to 122 Ma. Twenty five samples from 7 individual flows yielded acceptable paleointensity estimates. The mean paleointensity values per flow are ranging from 53.0±1.9 to 25.4±2.6 μT and the corresponding Virtual Dipole Moments (VDMs) are ranging from 9.3±1.3 to 4.6±0.5 (1022 Am2). This corresponds to the mean value of 7.3±1.7x1022 Am2, which is compatible to the present geomagnetic axial dipole. Currently available selected paleointensity data from 80 to 130 Ma suggest that geomagnetic field strength frequently fluctuated before and during the Cretaceous Normal Superchron while the magnetic polarity maintained stable. The mean paleointensities derived from Cordoba lavas agree remarkably well with those obtained from the Parana Magmatic Province (133-132 Ma). This reinforces the hypothesis about the unreliability of ‘Mesozoic Dipole Low'.Fil: Cejudo Ruiz, Ruben. Universidad Nacional Autónoma de México; MéxicoFil: Goguitchaichvili, Avto. Universidad Nacional Autónoma de México; MéxicoFil: Geuna, Silvana Evangelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Alva-Valdivia, Luis M.. Universidad Nacional Autónoma de México; MéxicoFil: Solé, Jesus. Universidad Nacional Autónoma de México; MéxicoFil: Morales, Juan. Universidad Nacional Autónoma de México; Méxic

Formulación de un plan de endomarketing para el fortalecimiento de la cultura organizacional en la empresa compañías asociadas de Gas S.A E.S.P de la ciudad de Bogotá

El pilar más importante de toda organización son sus empleados; si un empleado no está de acuerdo con la eficiencia o conveniencia de un producto, servicio o proyecto de la empresa, puede crear un efecto negativo a través de lo que haga en su trabajo o deje de hacer. Esto se convierte en un obstáculo más para la empresa y el producto en el camino de ser aceptados por el consumidor final externo. Por lo tanto, el endomarketing busca primero conquistar a los empleados a través de distintas actividades y demostraciones que los van comprometiendo más con los valores, objetivos, planes, productos, servicios y promociones de la empresa. Es indispensable para todas las organizaciones implementar estrategias de endomarketing que les permitan alcanzar la satisfacción de cada uno de los colaboradores, no solo en su cargo sino también en su vinculación y permanencia en la empresa, involucrando otros aspectos como el sistema retributivo, es decir, salario, recompensas e incentivos; el clima laboral, la imagen y posicionamiento de la empresa, sugestión, entre otros

Reconsiderando la metodología FAO sobre el cálculo del número de personas que pasan hambre en el mundo

FAO measure of undernourishment is calculated based on three main parameters: dietary energy supply (DES), minimum dietary energy requirement (MDER), and the coefficient of variation of dietary energy consumption (CV). In the current implementation of this methodology, the DES and the MDER change over time, as would be expected. The CV, however, remains constant. However, we expect the CV to change over time and be a function of income and prices. This paper discusses why the CV should change in response to changes in these variables, and suggests a practical way to estimate changes in the CV over time in the absence of survey data.Income, prices, consumption, undernourishment, Food Consumption/Nutrition/Food Safety, Food Security and Poverty, E21, O11, O19,