Challenges and perspectives for the protection of masonry structures in historic centers: the role of innovative materials and techniques

Lessons learned from natural events which caused severe damage to existing constructions have repeatedly shown the high vulnerability of historically important masonry, often worsened by inaccurate or dubious applications of modern or innovative interventions. Especially in the field of new technologies and materials applied to historical assets, experimental validation integrated at multi-disciplinary level is essential, to implement correct choices able to balance the respect of tradition and the requirements of innovation. The common objective is the transmission of educational values through the conservation of the historical identity of constructions which have survived over time and are still functional today. Planning agreements among academic and industrial research, management and governing bodies constitute preconditions for selecting consistent strategies for the protection of the built environment. However, the effects of technical advances and trends on historical assets should be carefully evaluated when influencing common practices, before recommendations, standards or execution protocols based on sufficiently long-lasting experience are available. This paper discusses a series of issues involved in the complex process of methodological and operative options currently feasible in the field of historical masonry structures. It also focuses on the progressive role of composite materials and the consequent implications on the implementation of preservation criteria

Heat Flow Density in a region with Hot Springs- NW of Portugal and SW of Galicia (Spain)

Heat flow density and temperature are studied in a region characterized by a very marked topography and the existence of thermal springs. The work was made with results obtained in studies involving heat sources in the region due to the decay of radioactive elements and detailed structure of the upper and middle crust, obtained with seismic data (receiver functions). Heat flow density and hot springs data used were obtained in the Atlas of Geothermal Resources in Europe. Gravity and magnetic data in the region were also used. Three groups of thermal springs were identified and studied. The heat flow density values in the region were analyzed and integrated in the region taking into account measurement depths of temperature, existing aquifers in the region (water reservoirs near the surface) and respective porosities. Temperatures and heat flow distribution in the region presents some differences from results obtained for the same region in other works previously publishe

The effect of concentration on the Surface-Enhanced Raman Scattering of p-Aminothiophenol

The organic compound p-aminothiophenol (pATP, HS-Ph-NH2) has become very popular because it is often used for checking the enhancement capability of each new SERS substrate due to its very intense SERS spectra. SERS of pATP on silver electrode is significantly different from its ordinary Raman spectra and it is very dependent on the particular conditions of the SERS experiment. In this work the effect of adsorbate concentration on the potential dependent SERS spectra of pATP recorded on a silver electrode has been studied using NaClO4 as electrolyte. On the other hand, MS-CASPT2 have been performed in order to help the analysis of the experimental results by computing resonance Raman spectra of selected structural models of the metal−adsorbate surface complex. It is found that the spectra are dependent on adsorbate concentration and dominated by a resonant charge transfer (CT) mechanism, where the charge is always transferred from the adsorbate to the metal. The relative SERS enhancements are due to Franck−Condon factors related to the CT process, and there are not intensified bands through Herzberg−Teller contributions. Furthermore, the Raman signals of the SERS recorded at low concentration arise from at least three different molecular species: (i) pATP bonded to silver electrode through sulfur atom (Agn-S−-Ph-NH2); (ii) pATP bonded to silver electrode through both sulfur and nitrogen atoms (Agn-S−-PhNH2-Agm); (iii) The azo derivative p,p′-dimercaptoazobenzene (or its nitrene precursor).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Mengoli's mathematical ideas in Leibniz's excerpts

In the seventeenth century many changes occurred in the practice of mathematics. An essential change was the establishment of a symbolic language, so that the new language of symbols and techniques could be used to obtain new results. Pietro Mengoli (1626/7–86), a pupil of Cavalieri, considered the use of symbolic language and algebraic procedures essential for solving all kinds of problems. Following the algebraic research of Viète, Mengoli constructed a geometry of species, Geometriae Speciosae Elementa (1659), which allowed him to use algebra in geometry in complementary ways to solve quadrature problems, and later to compute the quadrature of the circle in his Circolo (1672). In a letter to Oldenburg as early as 1673, Gottfried Wilhelm Leibniz (1646–1716) expressed an interest in Mengoli's works, and again later in 1676, when he wrote some excerpts from Mengoli's Circolo. The aim of this paper is to show how in these excerpts Leibniz dealt with Mengoli's ideas as well as to provide new insights into Leibniz's mathematical interpretations and commentsPeer ReviewedPostprint (author's final draft

Detection of different species of p-aminothiophenol on silver nanoparticles by Surface-Enhanced Raman Spectroscopy (SERS)

In the present work we have analyzed the experimental and theoretical SERS spectra of the organic compound p-aminothiophenol (pATP, HS-Ph-NH2) recorded on silver nanoparticles. DFT calculations have been performed to support the experimental results in order to estimate the adsorption specie and the corresponding Raman bands assignment. It is found a different adsorption behavior of pATP not only by changing the concentration of the adsorbate but also by exciting the sample at different wavelengths.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Random Walk Tests for the Lisbon Stock Market

This paper reports the results of tests on the weak-form market efficiency applied to the PSI-20 index prices of the Lisbon Stock Market from January 1993 to December 2006. As an emerging stock market, it is unlikely that it is fully information-efficient, but we show that the level of weak-form efficiency has increased in recent years. We use a serial correlation test, a runs test, an augmented Dickey-Fuller test and the multiple variance ratio test proposed by Lo and MacKinlay (1988) for the hypothesis that the stock market index follows a random walk. Non-trading or infrequent trading is not an issue because the PSI-20 only includes the 20 most traded shares. The tests are performed using daily, weekly and monthly returns for the whole period and for five sub-periods which reflect different trends in the market. We find mixed evidence, but on the whole, our results show that the Portuguese stock market index has been approaching a random walk behavior since year 2000, with a decrease in the serial dependence of returns.

Philosophical Theology and Christian Doctrines

This contribution discusses Leibniz’s views on key Christian doctrines which were surrounded, in the early modern period, by particularly lively debates. The first section delves into his defence of the Trinity and the Incarnation against the charge of contradiction, and his exploration of metaphysical models capacious enough to accommodate these mysteries. The second section focuses on the resurrection and the Eucharist with special regard to their connections with Leibniz’s metaphysics of bodies. The third section investigates Leibniz’s position on predestination, grace, salvation, and damnation. It comes to the conclusion that salvation, for Leibniz, does not ultimately depend on believing a set of true doctrines, but on a practical attitude: the love of God above all things. Leibniz’s theology is thus fundamentally a theology of love which is ultimately practical, and tries to be both universalist and Christian

Is the Dividend Puzzle Solved?

Since the 1960’s, there is an ongoing debate on dividend policy, which remains a controversial issue to this day. Why do firms pay dividends? The academics have not been able to agree on any convincing explanation, and the same time, many even claim that firms should not pay dividends, and so we have a “dividend puzzle”. The purpose of this paper is to summarize the main findings of two more recent fields of research, and to discuss why they seem to be the most promising avenues for further research, to solve the “dividend puzzle”, and to build a complete payout policy theory. These fields are: (i) the agency theory and (ii) the lifecycle theory. Besides being very intuitive, these theories are consistent with most empirical facts on U.S. firms’ payout policy.