Portfolio of compositions

This text contains a short general description of my experience at the University of Birmingham. This is an attempt to communicate how my perception in composing music has changed and evolved. The focus is to introduce briefly my experience before I arrived at the University of Birmingham, then go through all the compositions I have worked on during my PhD programme. This attempt is to explain the main processes I have used for composing, giving a wider view of the issues that I was interested in developing. Furthermore, I will consider some technical aspects with reference to facilities that the University of Birmingham offers to students. This appears to be the right opportunity for them to explore technology almost without any restrictions. I also give some information about other nonmusical issues, which I was interested in developing in order to look into personal aesthetic directions. My main reason for being at the University of Birmingham was to explore compositional processes different from my previous experiences, in order to enlarge my abilities and perspectives in music composition

Oxygen content variation and cation doping dependence of (La)1.4(Sr1-yCay)1.6Mn2O7 (y = 0, 0.25, 0.5) bilayered manganites properties

The results of the synthesis and characterization of the optimally doped (La)1.4(Sr1-yCay)1.6Mn2O7 solid solution with y=0, 0.25 and 0.5 are reported. By progressively replacing the Sr with the smaller Ca, while keeping fixed the hole-concentration due to the divalent dopant, the 'size effect' of the cation itself on the structural, transport and magnetic properties of the bilayered manganite has been analysed. Two different annealing treatments of the solid solution, in pure oxygen and in pure argon, allowed also to study the effect of the oxygen content variation. Structure and electronic properties of the samples have been investigated by means of X-ray powder diffraction and X-ray absorption spectroscopy measurements. Magnetoresistivity and static magnetization measurements have been carried out to complete the samples characterization. Oxygen annealing of the solid solution, that showed a limit for about y=0.5, induces an increase of the Mn average valence state and a transition of the crystal structure from tetragonal to orthorhombic while the argon annealing induces an oxygen under-stoichiometry and, in turn, a reduction of the Mn average valence state. Along with the Ca substitution, the Jahn-Teller distortion of the MnO6 octahedra is reduced. This has been directly connected to a general enhancement of the transport properties induced by the Ca-doping. For the same cation composition, oxygen over-stoichiometry leads to higher metal-insulator transition temperatures and lower resistivity values. Curie temperatures (TC) reduce by increasing the Ca-doping. The lower TC for all the annealed samples with respect to the 'as prepared' ones are connected to the strong influence on the magnetic interaction of the point defects due to the oxygen content variation.Comment: 49 pages, 13 figure

Wear rates in urban rail systems

A significant part of maintenance costs in urban rail systems (metro, tram, light rapid transit/light metro) is due to wheel-rail wear. Wear rates - measured for example as depth of wear per kilometre run (rolling stock) or per train passage (rails) - depend in a complex manner on several influence factors. Among the most important are key design factors of the rolling stock (wheel profiles, suspension characteristics), of the track (distribution of curve radii, characteristics of switches and crossings, rail profiles), of the wheel-rail interface (lubrication, materials in contact, ambient characteristics), and of operations (frequency of traction and braking, trainset inversion policy, maintenance policy etc.). When designing an urban rail system, all of these factors have to be under control in order to limit the costs due to wheel/rail reprofiling/grinding and replacement. The state of the art allows the calculation of wear rates given quantitative input regarding the above factors. However, it is difficult to find in the literature experimental values for calibration of wear models and indications on what is a reasonable state-of-the-art wear rate for any given type of urban rail system. In this paper we present a structured analysis of flange wear rates found in the literature and derived from the experience of the authors, for a variety of cases, including metros and mainline rail systems. We compare the wear rates and explain their relationship with the influence factors. We then relate the wear rates with the needs in terms of wheel reprofiling/replacement. We estimate ranges for the calibration coefficients of wear models. We present the results in a way as to allow the designer of urban rail systems to derive values for target wear rates according to their specific conditions without the need for complex simulations

Identificación de actividades futuras del Proyecto Atlas Digital de Costa Rica 2018

Proyecto de Investigación. Código del proyecto: 1801-085El proyecto Atlas Digital nace hace 16 años, con el objetivo de actualizar y adaptar la información geográfica de Costa Rica a los avances en cartografía digital. Los resultados del proyecto Atlas Digital de Costa Rica se han presentado a la comunidad nacional y mundial mediante medios masivos, y gracias a esta divulgación se han recibido propuestas y sugerencias para el perfeccionamiento futuro del Proyecto Atlas. Estas opciones y sugerencias deben analizarse y consultarse con los usuarios, con el fin de identificar cuáles de ellas son las que deben desarrollarse en los próximos años. El objetivo de esta actividad de fortalecimiento de la investigación fue identificar las opciones y proyectos futuros a desarrollar como continuación del proyecto Atlas Digital de Costa Rica. Se logró constatar que la mayoría de los usuarios del Atlas Digital de Costa Rica utilizan el Atlas en actividades de manejo y conservación de recursos naturales, ordenamiento territorial, y manejo de recursos forestales. Sin embargo, a la vez el 45% opinan que el Atlas debe seguir como hasta ahora proveyendo todo tipo de información geográfica. Por otro lado el 81,0% opina que también debería usarse la información del Atlas en el desarrollo de aplicaciones específicas, como el desarrollo de una aplicación “app” para la enseñanza de la geografía de Costa Rica. En esta iniciativa se logró también identificar las capas de datos de mayor uso, así como aquellas capas de datos nuevas que debieran incluirse en futuras actualizaciones del Atlas según la opinión de los usuarios. Al evaluar las alternativas de desarrollo futuro del proyecto Atlas se idéntica que debe especializarse en la producción de capas de datos de utilidad para el manejo y conservación de recursos naturales, pero sin dejar de lado la incorporación y actualización de datos geográficos de uso general del país. Siguiendo estos resultado se preparó una nueva propuesta de investigación y desarrollo que fue presentada a la Ronda de proyectos VIE-2017, y se espera poder preparar otras propuestas derivadas de esta para concursar por fondos externos

Complex railway systems: capacity and utilisation of interconnected networks

Introduction Worldwide the transport sector faces several issues related to the rising of traffic demand such as congestion, energy consumption, noise, pollution, safety, etc. Trying to stem the problem, the European Commission is encouraging a modal shift towards railway, considered as one of the key factors for the development of a more sustainable European transport system. The coveted increase in railway share of transport demand for the next decades and the attempt to open up the rail market (for freight, international and recently also local services) strengthen the attention to capacity usage of the system. This contribution proposes a synthetic methodology for the capacity and utilisation analysis of complex interconnected rail networks; the procedure has a dual scope since it allows both a theoretically robust examination of suburban rail systems and a solid approach to be applied, with few additional and consistent assumptions, for feasibility or strategic analysis of wide networks (by efficiently exploiting the use of Big Data and/or available Open Databases). Method In particular the approach proposes a schematization of typical elements of a rail network (stations and line segments) to be applied in case of lack of more detailed data; in the authors’ opinion the strength points of the presented procedure stem from the flexibility of the applied synthetic methods and from the joint analysis of nodes and lines. The article, after building a quasiautomatic model to carry out several analyses by changing the border conditions or assumptions, even presents some general abacuses showing the variability of capacity/utilization of the network’s elements in function of basic parameters. Results This has helped in both the presented case studies: one focuses on a detailed analysis of the Naples’ suburban node, while the other tries to broaden the horizon by examining the whole European rail network with a more specific zoom on the Belgium area. The first application shows how the procedure can be applied in case of availability of fine-grained data and for metropolitan/regional analysis, allowing a precise detection of possible bottlenecks in the system and the individuation of possible interventions to relieve the high usage rate of these elements. The second application represents an on-going attempt to provide a broad analysis of capacity and related parameters for the entire European railway system. It explores the potentiality of the approach and the possible exploitation of different ‘Open and Big Data’ sources, but the outcomes underline the necessity to rely on proper and adequate information; the accuracy of the results significantly depend on the design and precision of the input database. Conclusion In conclusion, the proposed methodology aims to evaluate capacity and utilisation rates of rail systems at different geographical scales and according to data availability; the outcomes might provide valuable information to allow efficient exploitation and deployment of railway infrastructure, better supporting policy (e.g. investment prioritization, rail infrastructure access charges) and helping to minimize costs for users.The presented case studies show that the method allows indicative evaluations on the use of the system and comparative analysis between different elementary components, providing a first identification of ‘weak’ links or nodes for which, then, specific and detailed analyses should be carried out, taking into account more in depth their actual configuration, the technical characteristics and the real composition of the traffic (i.e. other elements influencing the rail capacity, such as: the adopted operating systems, the station traffic/route control & safety system, the elastic release of routes, the overlap of block sections, etc.)

Reconstructing the galaxy density field with photometric redshifts: II. Environment-dependent galaxy evolution since z≃3z \simeq 3

Although extensively investigated, the role of the environment in galaxy formation is still not well understood. In this context, the Galaxy Stellar Mass Function (GSMF) is a powerful tool to understand how environment relates to galaxy mass assembly and the quenching of star-formation. In this work, we make use of the high-precision photometric redshifts of the UltraVISTA Survey to study the GSMF in different environments up to $z \sim 3$, on physical scales from 0.3 to 2 Mpc, down to masses of $M \sim 10^{10} M_{\odot}$. We witness the appearance of environmental signatures for both quiescent and star-forming galaxies. We find that the shape of the GSMF of quiescent galaxies is different in high- and low-density environments up to $z \sim 2$ with the high-mass end ($M \gtrsim 10^{11} M_{\odot}$) being enhanced in high-density environments. On the contrary, for star-forming galaxies a difference between the GSMF in high- and low density environments is present for masses $M \lesssim 10^{11} M_{\odot}$. Star-forming galaxies in this mass range appear to be more frequent in low-density environments up to $z < 1.5$. Differences in the shape of the GSMF are not visible anymore at $z > 2$. Our results, in terms of general trends in the shape of the GSMF, are in agreement with a scenario in which galaxies are quenched when they enter hot gas-dominated massive haloes which are preferentially in high-density environments.Comment: 18 pages, 10 figures. Accepted for publication in Monthly Notices of the Royal Astronomical Societ

Absence of Long Range Magnetic Order in the La1.4Sr0.8Ca0.8Mn2O7 Bilayered Manganite

In this work we studied, by means of high-resolution neutron diffraction as a function of temperature, the La1.4Sr0.8Ca0.8Mn2O7 bilayered manganite for two different annealing treatments. Out data allowed us to shown, for the first time, the absence of long-range magnetic order in this optimally doped bilayered manganite where the A-site of the structure is doped with equal proportions of different isovalent cations (Ca and Sr). The system, however, presents defined IM transitions which suggest that the transport properties are not linked to the evolution of long-range order and that two dimensional spin ordering in the layers of the perovskite blocks may be sufficient to 'assist' the hole hopping. Possible reason for the suppression of magnetic order induced by the Ca doping is a size effect coupled to the cation size mismatch between the Sr and Ca ions.Comment: 24 pages, 7 figure

Feeding behaviour of larval European sea bass (Dicentrarchus labrax L.) in relation to temperature and prey density

The feeding behaviour of larval European sea bass (Dicentrarchus labrax, L.) was analysed in relation to temperature and prey density under controlled laboratory conditions with the aim to assess the ability of larval fish to change the feeding tactic as a response to environmental changes. Larvae were acclimated for 20 days at three different temperatures (19, 22 and 26°C), and their feeding behaviour was then video-recorded in experimental trials, at two prey densities, consisting of swarms of 400/l and 1440/l Artemia nauplii. Results showed that there was a significant effect of the interaction between temperature and prey density on the proportion of swimming activity that was reduced at the high temperature-high prey density combination. This suggested a switching in the larval feeding behaviour from an active to an ambush tactic, when the temperature reached 26°C and the prey density was 1440 /l Artemia nauplii. These results are consistent with the current literature on fish larval behaviour in showing that the foraging tactic can be modulated by the interaction of different abiotic and biotic factors characterising the rearing environment

Novel Physical Vapor Deposition Approach to Hybrid Perovskites: Growth of MAPbI3 Thin Films by RF-Magnetron Sputtering

Solution-based methods represent the most widespread approach used to deposit hybrid organic-inorganic perovskite films for low-cost but efficient solar cells. However, solution-process techniques offer limited control over film morphology and crystallinity, and most importantly do not allow sequential film deposition to produce perovskite-perovskite heterostructures. Here the successful deposition of CH3NH3PbI3 (MAPI) thin films by RF-magnetron sputtering is reported, an industry-tested method to grow large area devices with precisely controlled stoichiometry. MAPI films are grown starting from a single-target made of CH3NH3I (MAI) and PbI2. Films are single-phase, with a barely detectable content of unreacted PbI2, full surface coverage and thickness ranging from less than 200 nm to more than 3 {\mu}m. Light absorption and emission properties of the deposited films are comparable to as-grown solution-processed MAPI films. The development of vapor-phase deposition methods is of interest to advance perovskite photovoltaic devices with the possibility of fabricating perovskite multijunction solar cells or multicolor bright light-emitting devices in the whole visible spectrum

Effect of gibberellic acid and temperature on germination of Vitex montevidensis Cham.

This work aims to evaluate treatments that may help improve speed and uniformity of germination in fruit tree species tarumã. Data were obtained from pyrenes (stones) of ripe fruits which in turn were picked from adult trees in the municipality of Vera Cruz do Oeste-PR. Treatments consisted of applying GA3 solutions at various concentrations (zero, 50 mg L-1, 100 mg L-1 or 200 mg L-1) to pyrenes via immersion for 47 hours, and thermoperiods of alternate 20ºC and 30ºC (8 hours at 20ºC in light conditions, and 16 hours at 30ºC in dark conditions) and constant 30ºC with the same photoperiod. The combination of alternate temperatures of 20ºC and 30ºC with a 200 mg L-1 GA3 solution resulted in an increase both in germination percentage, from 19.2% to 56.2%, and in the germination speed index, from 0.19 to 3.12, with resulting normal, uniform seedlings