Investigação de Er3+ nos dois sítios cristalográficos de Gd2SiO5 através da fotoluminescência resolvida no tempo

Gadolinium oxyortho-silicate, Gd2SiO5, presents a monoclinic structure with two crystallographic sites in which Gd3+ ions are equally distributed with coordination numbers CN, 7 and 9, respectively. By doping this host with Er3+ it is possible to distinguish and attribute the two sites by means of lifetime determination of the 4S3/2 state, (in this case, Er3+ substitutes Gd3+ ions). Samples doped with 0.1 and 5.0% molar Er3+ were prepared by solid state reaction and characterized by X-ray Diffractometry, Vibrational and Electronic Absorption Spectroscopies, and Time Resolved Photoluminescence. Based on the experimental results, it is possible to verify that, for the 5,0% doped sample, the lifetime value of the 4S3/2 state of the erbium ion inserted in site 1, (CN = 9), is 2.7 ± 0.1 mus, and for the one inserted in site 2, (CN = 7), it is 1.5 ± 0.1 mus.

Evidence for coseismic events of recurrent prehistoric deformation along the Alhama de Murcia fault, southeastern Spain

The Alhama de Murcia fault is a 85 km long oblique-slip fault, and is related to historical and instrumental seismic activity. A paleoseismic analysis of the Lorca-Totana sector of the fault containing MSK I=VIII historical earthquakes was made in order to identify and quantify its seismic potential. We present 1) the results of the neotectonic, structural and geomorphological analyses and, 2) the results of trenching. In the study area, the Alhama de Murcia fault forms a depressed corridor between two strands, the northwestern fault with morphological and structural features of a reverse component of slip, bounding the La Tercia range to the South, and the southeastern fault strand with evidence of sinistral oblique strike-slip movement. The offset along this latter fault trapped the sediments in transit from the La Tercia range towards the Guadalentín depression. The most recent of these sediments are arranged in three generations of alluvial fans and terraces. The first two trenches were dug in the most recent sediments across the southeastern fault strand. The results indicate a coseismic reverse fault deformation that involved the sedimentary sequence up to the intermediate alluvial fan and the Holocene terrace deposits. The sedimentary evolution observed in the trenches suggests an event of temporary damming of the Colmenar creek drainage to the South due to uplifting of the hanging wall during coseismic activation of the fault. Trench, structural and sedimentological features provide evidence of at least three coseismic events, which occurred after 125,000 yr. The minimum vertical slip rate along the fault is 0.06 mm/yr and the average recurrence period should not exceed 40,000 yr in accordance with the results obtained by fan topographic profiling. Further absolute dating is ongoing to constrain these estimates.

Active tectonics of the Alhama de Murcia fault, Betic Cordillera, Spain

We present an overview of the knowledge of the structure and the seismic behavior of the Alhama de Murcia Fault (AMF). We utilize a fault traces map created from a LIDAR DEM combined with the geodynamic setting, the analysis of the morphology, the distribution of seismicity, the geological information from E 1:50000 geological maps and the available paleoseismic data to describe the recent activity of the AMF. We discuss the importance of uncertainties regarding the structure and kinematics of the AMF applied to the interpretation and spatial correlation of the paleoseismic data. In particular, we discuss the nature of the faults dipping to the SE (antithetic to the main faults of the AMF) in several segments that have been studied in the previous paleoseismic works. A special chapter is dedicated to the analysis of the tectonic source of the Lorca 2011 earthquake that took place in between two large segments of the fault.

O papel dos programas interlaboratoriais para a qualidade dos resultados analíticos

Interlaboratorial programs are conducted for a number of purposes: to identify problems related to the calibration of instruments, to assess the degree of equivalence of analytical results among several laboratories, to attribute quantity values and its uncertainties in the development of a certified reference material and to verify the performance of laboratories as in proficiency testing, a key quality assurance technique, which is sometimes used in conjunction with accreditation. Several statistics tools are employed to assess the analytical results of laboratories participating in an intercomparison program. Among them are the z-score technique, the elypse of confidence and the Grubbs and Cochran test. This work presents the experience in coordinating an intercomparison exercise in order to determine Ca, Al, Fe, Ti and Mn, as impurities in samples of silicon metal of chemical grade prepared as a candidate for reference material.

Present-day deformation of the Pyrenees revealed by GPS surveying and earthquake focal mechanisms until 2011

The Pyrenean mountain range is a slowly deforming belt with continuous and moderate seismic activity. To quantify its deformation field, we present the velocity field estimated from a GPS survey of the Pyrenees spanning 18 yr. The PotSis and ResPyr networks, including a total of 85 GPS sites, were installed and first measured in 1992 and 1995 1997, respectively, and remeasured in 2008 and 2010. We obtain a deformation field with velocities less than 1 mm yr−1 across the range. The estimated velocities for individual stations do not differ significantly from zero with 95 per cent confidence. Even so, we estimate a maximum extensional horizontal strain rate of 2.0 ± 1.7 nanostrain per year in a N S direction in the western part of the range. We do not interpret the vertical displacements due to their large uncertainties. In order to compare the horizontal strain rates with the seismic activity, we analyse a set of 194 focal mechanisms using three methods: (i) the 'r' factor relating their P and T axes, (ii) the stress tensors obtained by fault slip inversion and (iii) the strain-rate tensors. Stress and strain-rate tensors are estimated for: (i) the whole data set, (ii) the eastern and western parts of the range separately, and (iii) eight zones, which are defined based on the seismicity and the tectonic patterns of the Pyrenees. Each of these analyses reveals a lateral variation of the deformation style from compression and extension in the east to extension and strike-slip in the west of the range. Although the horizontal components of the strain-rate tensors estimated from the seismic data are slightly smaller in magnitude than those computed from the GPS velocity field, they are consistent within the 2σ uncertainties. Furthermore, the orientations of their principal axes agree with the mapped active faults.

Extending the roughness of the data via transitive closures of similarity indexes

One main assumption in the theory of rough sets applied to information tables is that the elements that exhibit the same information are indiscernible (similar) and form blocks that can be understood as elementary granules of knowledge about the universe. We propose a variant of this concept defining a measure of similarity between the elements of the universe in order to consider that two objects can be indiscernible even though they do not share all the attribute values because the knowledge is partial or uncertain. The set of similarities define a matrix of a fuzzy relation satisfying reflexivity and symmetry but transitivity thus a partition of the universe is not attained. This problem can be solved calculating its transitive closure what ensure a partition for each level belonging to the unit interval [0,1]. This procedure allows generalizing the theory of rough sets depending on the minimum level of similarity accepted. This new point of view increases the rough character of the data because increases the set of indiscernible objects. Finally, we apply our results to a not real application to be capable to remark the differences and the improvements between this methodology and the classical one

Estudio de alta resolución de las fallas activas y procesos sedimentarios asociados al Cañón de São Vicente, margen Sudoeste de Iberia

The Southwest Iberian Margin is caracterized by an intense and diffuse seismic activity due to the convergence between Eurasian and African plates...

Bromofenóis simples relacionados ao "flavor" de organismos marinhos

The perception of the flavor is an important attribute of quality in marine fish and other seafoods, being the first and main factor of discrimination for the evaluation, later acceptance and preference of the product by the consumer. Recently, the simple bromophenols have been considered an important group of key flavor compounds occurring in a wide variety of seafood species like fishes, mollusks, crustaceans and algae. When present in high concentration, in seafood, the bromophenols produce an undesirable flavor and are associated with inferior quality. Meanwhile, when present in low concentration levels (for example ng g-1) these compounds produce a desirable marine - or ocean-like - flavor and enhance the existing flavor in seafood. Indeed, simple bromophenols are widespread in seafood but virtually absent in freshwater fish. Herein we present a review on these flavor components found in the marine environment.

Veus ignorades: representacions socials, subjectivitat i resiliència en persones grans amb pèrdua d’autonomia funcional

Els processos per a l’aprovació i la implementació de la Llei per a l’Autonomia personal i l’Atenció a les Persones en situació de Dependència (LAPAD) han donat lloc a un intens debat polític i social que, coincidint també amb les millores en la provisió de serveis i els avenços mèdics, ha contribuït a un procés de classificació i d’etiquetatge basats en els dèficits de les persones que es troben en aquestes circumstàncies. Aquesta visió anul·la el subjecte i la seva experiència singular i condiciona l’abordatge dels models d’atenció i de cura. L’estudi pretén fer una aproximació a les persones grans amb pèrdua d’autonomia funcional, fent emergir les seves veus, que expressen com perceben, interpreten, afronten i es reajusten a la nova situació. Partint d’un enfocament constructivista, basat en la subjectivitat, es fa un recorregut sobre els models de la discapacitat que han reeixit en l’activitat científica dels darrers anys, els mecanismes de regulació de les pèrdues que defensen les teories del cicle vital i les aportacions que s’han fet sobre el model de la resiliència aplicat a les persones que envelleixen. El resultats de l’estudi mostren com les representacions i els significats que les persones grans atribueixen a la seva experiència s’inscriuen en les seves trajectòries vitals, donant un sentit únic i singular a la forma de viure i de respondre a la pèrdua d’autonomia funcional i les seves conseqüències. Aquelles que expressen una vivència d’integritat respecte de la vida viscuda, amb predomini d’afectes positius envers un mateix i els altres, que conserven l’esperança i el desig de continuar vivint, s’ajusten a les pèrdues de manera més satisfactòria que aquelles que expressen desconfiança i una certa amargor respecte de la pròpia vida. D’això se’n deriva que els espais d’escolta i d’acompanyament poden ser un recurs vàlid i necessari en el qual, a través de la paraula i el testimoni narrat, el subjecte pugui repensar i resignificar les seves experiències.

Development of Color Difference Equations Matching to Human Vision System

Research on color difference evaluation has been active in recent thirty years. Several color difference formulas were developed for industrial applications. The aims of this thesis are to develop the color density which is denoted by comb g and to propose the color density based chromaticity difference formulas. Color density is derived from the discrimination ellipse parameters and color positions in the xy , xyY and CIELAB color spaces, and the color based chromaticity difference formulas are compared with the line element formulas and CIE 2000 color difference formulas. As a result of the thesis, color density represents the perceived color difference accurately, and it could be used to characterize a color by the attribute of perceived color difference from this color.

Testausmenetelmien ja testauksen lähestymistapojen valintaperusteet kirjallisuudessa

Testaustapausten valitseminen on testauksessa tärkeää, koska kaikkia testaustapauksia ei voida testata aika- ja raharajoitteiden takia. Testaustapausten valintaan on paljon eri menetelmiä joista eniten esillä olevat ovat malleihin perustuva valinta, kombinaatiovalinta ja riskeihin perustuva valinta. Kaikkiin edellä mainittuihin menetelmiin testaustapaukset luodaan ohjelman spesifikaation perusteella. Malleihin perustuvassa menetelmässä käytetään hyväksi ohjelman toiminnasta olevia malleja, joista valitaan tärkeimmät testattavaksi. Kombinaatiotestauksessa testitapaukset on muodostettu ominaisuuspareina jolloin yhden parin testaamisesta päätellään kahden ominaisuuden toiminta. Kombinaatiotestaus on tehokas löytämään virheitä, jotka johtuvat yhdestä tai kahdesta tekijästä. Riskeihin perustuva testaus pyrkii arvioimaan ohjelman riskejä ja valitsemaan testitapaukset niiden perusteella. Kaikissa menetelmissä priorisointi on tärkeässä roolissa, jotta testauksesta saadaan riittävä luotettavuus ilman kustannusten nousua.

A formação em Química discutida com base nos modelos proposto por estudantes de pós-graduação para o fenômeno de dissolução

Mental models play an important role in the evolution of an individual's so-called knowledge. Using such representations, students can explain, foresee, and attribute causality to observed phenomena. In the case of Chemistry, the ability to work mentally with models assumes great importance, due to the microscopic component that is characteristic of this science. With the objective of exploring students' ability to work with models, 27 students of the Chemistry Institute of UNESP were asked to describe the mechanisms of dissolution, in water, of NaCl, HCl and HCN, as well as the partial dissolution of I2. Due to difficulties of access to complex descriptors of these processes, each student was asked to explain the phenomena using words and drawings. The results of these investigations were analyzed, and enabled construction of a framework representing the Chemistry students' theoretical training, especially with respect to their most important transferred skill: an ability to model the physical world.

The effect of institutional settings on accounting conservatism – Empirical evidence from the Nordic countries and the transitional economies of Europe

The purpose of the dissertation is to investigate how different institutional settings affect accounting conservatism. These aspects are of interest because prior studies show that accounting quality is influenced not only by accounting standards, but also by incentives from the financial reporting environment. Accounting quality could be defined as the usefulness of financial reporting to investors and other parties in contractual relationships with the firm. In this thesis it is measured by a single, but important attribute, accounting conservatism. Conservatism is understood as asymmetric timeliness of loss and gain recognition. The study examines the role and the users of financial statements, and how changes in both respectively affect accounting conservatism. These two questions are explored in two different research environments, the Nordic countries and the transitional economies of Europe. The results of the dissertation indicate that the degree of accounting conservatism increases the closer the financial statement comes to fulfilling the informational role of financial reporting. Secondly, it is also implied that foreign investors demand conservative accounting numbers in order to mitigate the problem of information asymmetry. Overall, the findings suggest that earnings conservatism is useful and increases the quality of financial information for the purpose of decision-making and contracting. These results are of relevance to managers, investors and other users of financial reporting information, as well as to standard setters.

Costs and Benefits of a Shared Digital Long-Term Preservation System

Paper presented at the 40th Annual Conference of LIBER (Ligue des Bibliothèques Européennes de Recherche - Association of European Research Libraries) on July 1st, 2011; with the slides used at the presentation.

Integrating user experience into early phases of software development

The value and benefits of user experience (UX) are widely recognized in the modern world and UX is seen as an integral part of many fields. This dissertation integrates UX and understanding end users with the early phases of software development. The concept of UX is still unclear, as witnessed by more than twenty-five definitions and ongoing argument about its different aspects and attributes. This missing consensus forms a problem in creating a link between UX and software development: How to take the UX of end users into account when it is unclear for software developers what UX stands for the end users. Furthermore, currently known methods to estimate, evaluate and analyse UX during software development are biased in favor of the phases where something concrete and tangible already exists. It would be beneficial to further elaborate on UX in the beginning phases of software development. Theoretical knowledge from the fields of UX and software development is presented and linked with surveyed and analysed UX attribute information from end users and UX professionals. Composing the surveys around the identified 21 UX attributes is described and the results are analysed in conjunction with end user demographics. Finally the utilization of the gained results is explained with a proof of concept utility, the Wizard of UX, which demonstrates how UX can be integrated into early phases of software development. The process of designing, prototyping and testing this utility is an integral part of this dissertation. The analyses show statistically significant dependencies between appreciation towards UX attributes and surveyed end user demographics. In addition, tests conducted by software developers and industrial UX designer both indicate the benefits and necessity of the prototyped Wizard of UX utility. According to the conducted tests, this utility meets the requirements set for it: It provides a way for software developers to raise their know-how of UX and a possibility to consider the UX of end users with statistical user profiles during the early phases of software development. This dissertation produces new and relevant information for the UX and software development communities by demonstrating that it is possible to integrate UX as a part of the early phases of software development.