Can the standard impact tests become a true materials evaluation tool?

Impact resistance constitutes one of the most popular quality control tools for polymeric materials and plastic finished parts. There are a number of standard impact test methods devoted to evaluate the impact response of polymeric materials (e.g., tensile-impact, Charpy and Izod tests, falling weight, Gardner, etc.). Nevertheless, to the questions: which test to use? how the different toughness measurements are related between each other? straightforward answers cannot be given. The shortcomings of standardized impact tests were recognized long ago: these tests are unable to generate an ‘actual material property’.Fil: Frontini, Patricia Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Combination of indirect measurements to improve sigmal estimation

A form to combine two kinds of indirect measurements to be processed together is proposed for illconditioned problems. Linear individual measurements with unknown proportionality constants jointly considered determine a unique non-linear problem. To solve this problem a method that includes in a single step the recovery of the signal and the calculation of the regularization parameter according to the Generalized Cross Validation technique is proposed. In order to investigate the convenience of simultaneous versus individual processing, a set of synthetic experiments performed on suspensions of polystyrene particles is analyzed. The results clearly show that when the data are jointly processed the quality of the Particle Size Distribution estimated is highly superior. This work shows that simultaneous processing of experimental data from different sources seems to be a valid alternative to improve the quality of indirect measurements.Fil: Frontini, Gloria Lia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Elicabe, Guillermo Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Depth sensing indentation of organic-inorganic hybrid coatings deposited onto a polymeric substrate

PEO-Si/SiO2 hybrid coatings deposited onto a PVC substrate were micromechanically characterized using depth sensing indentation. The effect of curing time and coating thickness was investigated. Elastic moduli of coated systems determined by the Oliver–Pharr approach displayed a continuous decreasing trend with increasing indentation depth, reflecting that the hybrids are stiffer than the substrate. Aiming to extract coating-only elastic modulus a simple method based on FE simulations was developed. The method was applied to evaluate the moduli of the hybrid coatings and the values were compared with those obtained by applying different approaches available in literature. The elastic modulus of PEO-Si/SiO2 hybrids was proven to be practically independent of curing time after 24 h. However, large curing times resulted in coatings being more prone to failure.Fil: Fasce, Laura Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Seltzer, Rocío. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Frontini, Patricia Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Federalist rhetoric or political tactics? The what, where, who, when and why of Juncker’s call for a common European army. EPC Commentary, 12 March 2015

In an interview with the German newspaper Welt am Sonntag on 8 March 2015, the President of the European Commission, Jean-Claude Juncker, strongly advocated a common European army to consolidate peace in Europe, react to security threats both within the continent and in its neighbourhood, defend European values vis-à-vis aggressive powers, notably Russia, and create economies of scale by consolidating demand for military equipment

Ensuring the EU’s future as a security provider Five recommendations for the June European Council’s session on CSDP. EPC Commentary, 23 June 2015

On 25 and 26 June 2015, the Heads of State or Government of the European Union (EU) will convene to discuss the implementation of their Conclusions on the Common Security and Defence Policy (CSDP) from December 2013. A substantial and frank debate among EU leaders is urgently needed in order to forge a lasting and credible vision for CSDP

Some unpleasant arithmetics of regional unemployment in the EU. Are there any lessons for EMU?

Several studies have documented the weak response of regional wage differentials and labour mobility following region-specific (“idiosyncraticâ€) shocks in the average of the EU countries. This has been often taken as evidence of the rigidity of labour markets in European countries, as opposed to the flexibility of the USA. However, as such shocks by definition average to zero, one cannot make an explicit link between the (lack of) adjustment at regional level and aggregate unemployment. Moreover, the emphasis on the reaction to short-run idiosyncratic shocks is unlikely to explain the permanent differentials across regions, which characterise the regional distribution of unemployment in many EU countries. This paper tries to provide a better understanding of the regional distribution of unemployment and why region-specific shocks can matter for aggregate unemployment. It does so by explicitly considering the possibility of asymmetric reactions, so that unemployment rises more in poorer areas suffering an adverse shock than it declines in richer regions experiencing a favourable shock. The reason behind such asymmetries is the presence of a wage floor in the poorer regions resulting from policy centralisation, as for instance in the case of a national unemployment compensation system, which provides benefits that are uniform across regions. If such a mechanism is at work, aggregate unemployment tends to be “inflated†by region-specific shocks that are inequality- increasing. After presenting an illustrative model of the mechanism, the paper proposes a simple measure of the resulting “excess unemploymentâ€, based on the difference between the average (national) unemployment rate and the unemployment rate of the median region. It also examines the relationship between regional asymmetries in unemployment and the dispersion of productivity across regions, taken as proxy of the inequality-increasing shocks. The evidence, while not entirely conclusive, justifies two tentative policy conclusions, which are particularly relevant in the context of EMU: a) to avoid centralisation of labour market institutions at the EU level that may end up inflating aggregate unemployment; b) to effectively deploy regional policies to combat inequality- increasing shocks.regional policy, unemployment, disparities

Implementation of a new bi-directional solar modelling method for complex facades within the ESP-r building simulation program

This paper provides an overview of a new method for modelling the total solar energy transmittance. It is implemented in the ESP-r building simulation program to model complex façades such as double glazed façades with external, internal or integrated shading devices. This new model has been validated and tested for several cases. The new model required changes to the solar control simulation algorithm and the user interface, so a new “Advanced optics menu” was also introduced into ESP-r. The paper presents the interface development and application of the new technique to different simulation configurations (especially different complex façades with shading devices) in a standard office building

Diplomatic parade or last struggle against fatalism? - Making sense of the Paris ministerial meeting on the Middle East Peace Process. EPC Commentary, 16 June 2016

On 3 June, the French government convened an international meeting in Paris, gathering 28 high-level delegations from all around the world, from Norway to Japan, in order to discuss the state of play and future prospects of the enduring Israel-Palestine conflict. The first ministerial meeting of the “Initiative for the Peace in the Middle East”, as it was labelled by the Quai d’Orsay, provided an important political signal, and a potential diplomatic format, to help revive the long-stalled peace process. Yet, its concrete deliverables remain beset by considerable uncertainty

A historic reminder, an ever-present dilemma? - Assessing Brexit’s potential consequences for European security. EPC Commentary, 18 May 2016

On 9 May 2016, in a further attempt to discourage the British public opinion from opting for their country’s abandonment of the European Union (EU) in the ‘in/out’ referendum on 23 June, Prime Minister David Cameron stated that the UK has regretted "turning its back" on Europe in the past, and that the EU had "helped reconcile" countries and maintain peace on the Old Continent

‘Bibi strikes back’. Israeli elections in a transforming domestic and international landscape. EPC Commentary, 26 March 2015

On 17 March 2015 Israeli citizens massively headed to the polls to renew the composition of the Knesset, the country’s legislative body, thereby also electing a new government after the early termination of the ruling coalition elected in 2013