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The structural, vibrational and electronic properties of the compressed beta-Sb2O3 polymorph, a.k.a. mineral valentinite, have been investigated in a joint experimental and theoretical study up to 23 GPa. The compressibility of the lattice parameters, unit-cell volume and polyhedral unit volume as well as the behaviour of its Raman- and IR-active modes under compression have been interpreted on the basis of ab initio theoretical simulations. Valentinite shows an unusual compressibility up to 15 GPa with four different pressure ranges, whose critical pressures are 2, 4, and 10 GPa. The pressure dependence of the main structural units, the lack of soft phonons, and the electronic density charge topology address the changes at those critical pressures to isostructural phase transitions of degree higher than 2. In particular, the transitions at 2 and 4 GPa can be ascribed to the changes in the interaction between the stereochemically-active lone electron pairs of Sb atoms under compression. The changes observed above 10 GPa, characterized by a general softening of several Raman- and IR-active modes, point to a structural instability prior to the 1st-order transition occurring above 15 GPa. Above this pressure, a tentative new high-pressure phase (s.g. Pcc2) has been assigned by single-crystal and powder X-ray diffraction measurements.

High-pressure X-ray diffraction studies on nanocrystals of the GdBO3 and YBO3 rare-earth orthoborates are herein reported up to 17.4(2) and 13.4(2) GPa respectively. The subsequent determination of the room-temperature pressure-volume equations of state is presented and discussed in the context of contemporary publications which contradict the findings of this work. In particular, the isothermal bulk moduli of GdBO3 and YBO3 are found to be 170(13) and 163(13) GPa respectively, almost 50% smaller than recent findings. Our experimental results provide an accurate revision of the high-pressure compressibility behaviour of GdBO3 and YBO3 which is consistent with the known systematics in isomorphic borates and previous ab initio calculations. Finally, we discuss how experimental/analytical errors could have led to unreliable conclusions reported elsewhere. © 2021 Elsevier B.V.

The structural stability and physical properties of CrVO4 under compression were studied by X-ray diffraction, Raman spectroscopy, optical absorption, resistivity measurements, and ab initio calculations up to 10 GPa. High-pressure X-ray diffraction and Raman measurements show that CrVO4 undergoes a phase transition from the ambient pressure orthorhombic CrVO4-type structure (Cmcm space group, phase III) to the high-pressure monoclinic CrVO4-V phase, which is isomorphic to the wolframite structure. Such a phase transition (CrVO4-type → wolframite), driven by pressure, also was previously observed in indium vanadate. The crystal structure of both phases and the pressure dependence in unit-cell parameters, Raman-active modes, resistivity, and electronic band gap, is reported. Vanadium atoms are sixth-fold coordinated in the wolframite phase, which is related to the collapse in the volume at the phase transition. Besides, we also observed drastic changes in the phonon spectrum, a drop of the band-gap, and a sharp decrease of resistivity. All the observed phenomena are explained with the help of first-principles calculations., Validerad;2020;Nivå 2;2020-07-10 (johcin)

There is marked trend to reduce education to a set of subjects oriented to intellectual development (reading and writing, mathematics, history, geography, natural sciences, and even religion and moral and civic edu-cation). This type of teaching privileges thinking and understates the role of emotions and the body in the social life of the individual. In the 19th century, as part of nation building, the Hispanic American republics felt urgent needs to discipline the body and to forge senses of identity, community, homeland and nation. The family became a key factor in this process as schooling was poor and non-compulsory. This paper examines the key role that music and dance had in the education of Hispanic American citizens in the 19th century., Existe una fuerte tendencia a reducir la educación a un conjunto de asignaturas destinadas a la formación inte-lectual de los individuos (lectura, escritura, matemáticas, historia, geografía, ciencias naturales, e incluso religión, educación moral y cívica). Este tipo de enseñanza privile-gia el pensamiento, ignorando la importancia del cuerpo y las emociones en el desempeño social del individuo. En el siglo XIX -periodo en el cual se constituyeron las repúbli-cas hispanoamericanas- disciplinar el cuerpo y forjar los sentimientos de identidad, comunidad, patria y nación, se constituían necesidades perentorias. Más allá de la escasa escolarización, y la falta de obligatoriedad de la misma, fue en el seno de las familias donde se produjo gran parte de este proceso. Este trabajo explora el papel fundamental que desempeñaron el baile y la música en la educación de los ciudadanos hispanoamericanos del siglo XIX.

The topical theory is one of the most successful and widespread theories of current musicology. Initially formulated within the English-speaking academy for the study of the classical period, its use has been extended to other schools, eras and musical styles. In Latin America it has been cultivated with assiduity, since it allows to explain plausibly and with particular efficiency some typical phenomena of great importance in the continent, such as musical nationalism or the complex links between jazz and local music. This article aims to show some of the problems that arise when topical theory is applied to music of a different nature for which it was originally conceived, as is the case of Latin American music as a whole. These problems seem clearly linked to the semiotic drift acquired by the topical theory. In this sense, we intend to analyze these problems, and propose a different approach based on Discourse Analysis Studies. To do this, we will examine some concrete examples where the theory –as it has been formulated so far– results inoperative; we will also criticize what we have called “extended topical theory”; we will examine the musical topic in the light of pragmatics and the theory of relevance; and we will offer a small final exercise that shows why a topic cannot be considered a sign, but a function that derives from the interaction between emitters, receivers and text., A teoria das tópicas é uma das mais bem-sucedidas e difundidas da musicologia atual. Inicialmente formulada no seio da academia de língua inglesa para o estudo do período clássico, foi posteriormente estendida a outras escolas, épocas e estilos musicais. Na América Latina, ela é usada com alguma frequência, pois permite explicar de maneira plausível e com particular eficácia, alguns fenômenos de grande importância no continente, como o nacionalismo musical ou as complexas fusões entre jazz e música local. Este artigo tenta explicar alguns dos problemas que surgem ao aplicar os princípios da teoria das tópicas à música de uma ordem diferente para a qual ela foi originalmente concebida, como é o caso da música latino-americana como um todo. Esses problemas parecem claramente ligados à deriva semiótica que, com o tempo, adquiriu a teoria das tópicas. Nesse sentido, pretendemos analisar esses problemas e propor uma abordagem diferente, baseada em estudos de análise de discurso. Para isso, examinaremos alguns exemplos concretos em que a teoria – tal como foi formulada até agora – é inoperante; estabeleceremos uma crítica ao que chamamos de “teoria tópica estendida”; examinaremos a tópica musical à luz da pragmática e da teoria da relevância; e faremos um pequeno exercício final que procura demonstrar a razão pela qual uma tópica não é um sinal, mas uma função que deriva da interação entre emissores, receptores e texto., La teoría tópica constituye una de las más exitosas y difundidas de la musicología actual. Formulada inicialmente en el seno de la academia de habla inglesa para el estudio del período clásico, su uso se ha extendido a otras escuelas, épocas y estilos musicales. En América Latina se la ha cultivado con asiduidad, dado que permite explicar plausiblemente y con particular eficacia algunos fenómenos propios, como el nacionalismo musical o las complejas fusiones habidas entre el jazz y las músicas locales, de mucha importancia en el continente. El presente artículo procura dar cuenta de algunos de los problemas que se presentan a la hora de aplicar los postulados de la teoría tópica a músicas de un orden diferente para las que fue originalmente concebida, como es el caso de la música latinoamericana en su conjunto. Estos problemas parecen claramente vinculados a la deriva semiótica que con el tiempo fue adquiriendo la teoría tópica. En tal sentido, pretendemos analizarlos y proponer un enfoque distinto a partir de los estudios de Análisis del discurso. Para ello, examinaremos algunos ejemplos concretos donde la teoría –tal como se ha formulado hasta ahora– resulta inoperante; haremos una crítica a lo que hemos llamado “teoría tópica extendida”; examinaremos el tópico musical a la luz de la pragmática y la teoría de la relevancia; y haremos un pequeño ejercicio final que evidencia por qué un tópico no puede ser considerado como un signo, sino una función que deriva de la interacción entre emisores, receptores y texto

We report a joint experimental and theoretical investigation of the high pressure structural and vibrational properties of terbium sesquioxide (Tb2O3). Powder X-ray diffraction and Raman scattering measurements show that cubic Ia3̅ (C-type) Tb2O3 undergoes two phase transitions up to 25 GPa. We observe a first irreversible reconstructive transition to the monoclinic C2/m (B-type) phase at ∼7 GPa and a subsequent reversible displacive transition from the monoclinic to the trigonal P3̅m1 (A-type) phase at ∼12 GPa. Thus, Tb2O3 is found to follow the well-known C → B → A phase transition sequence found in other cubic rare earth sesquioxides with cations of larger atomic mass than Tb. Our ab initio theoretical calculations predict phase transition pressures and bulk moduli for the three phases in rather good agreement with experimental results. Moreover, Raman-active modes of the three phases have been monitored as a function of pressure, while lattice-dynamics calculations have allowed us to confirm the assignment of the experimental phonon modes in the C- and A-type phases as well as to make a tentative assignment of the symmetry of most vibrational modes in the B-type phase. Finally, we extract the bulk moduli and the Raman-active mode frequencies together with their pressure coefficients for the three phases of Tb2O3. These results are thoroughly compared and discussed in relation to those reported for rare earth and other related sesquioxides as well as with new calculations for selected sesquioxides. It is concluded that the evolution of the volume and bulk modulus of all the three phases of these technologically relevant compounds exhibit a nearly linear trend with respect to the third power of the ionic radii of the cations and that the values of the bulk moduli for the three phases depend on the filling of the f orbitals.

La historia de la cumbia no se desarrolla de forma lineal. Aunque la «tradición» impide considerar fenómenos por fuera del relato secuencial, también trae consigo una preocupación por los discursos que la legitiman. La cumbia en Latinoamérica debe entenderse como un asunto virulento, de intercambios y pactos, más que como un lazo genitivo de filiación. Por ello, este libro busca conocer los procesos de contagio e inoculación del fenómeno, casi siempre promovidos por estrategias de difusión comercial, intereses de configuración simbólica y discursos ideológicos. Así, antes de hablar de la cumbia en Latinoamérica, se hace referencia a «las cumbias», en plural, ya que se trata de variaciones y transformaciones que definen trayectorias y construyen imaginarios.

Sol de América (1981-1982) is a composition for narrator, choir and orchestra by the Uruguayan composer Antonio Mastrogiovanni (1936-2010). The present study adopts the hermeneutic method (Nattiez, 1990) to give an account of this work based on the analysis of its orchestration. In this case, textures, timbres and sonorities are given precedence over harmony, pitch or form, parameters that are usually prioritized in most analytical methods. As a result, an unprecedented vision of music is obtained from a perspective that permits the discovery of the strongly cohesive properties of the orchestration, Sol de América (1981-1982) es una composición para narrador, coro y orquesta del compositor uruguayo Antonio Mastrogiovanni (1936-2010). El presente estudio utiliza el método hermenéutico (Nattiez, 1990) para dar cuenta de esta obra a partir del análisis de su orquestación. En este caso, se le da preeminencia a las texturas, timbres y sonoridades por encima de la armonía, las alturas o la forma, parámetros que usualmente se priorizan en la mayoría de los métodos analíticos. Como resultado se obtiene una visión inédita de la música, desde una perspectiva que permite descubrir las propiedades fuertemente cohesivas de la orquestación.

Metavalent or resonant bonding is a recently proposed new class of bonding that is intermediate between p-type covalent bonding and metallic bonding. It characterizes a new family of materials known as “incipient metals” [1]. Metavalent bonding occurs in materials where there is a deficiency of valence electrons in the unit cell to form a large number of bonds, such as in octahedrally-coordinated rocksalt-related structures occurring in GeTe, SnTe, PbSe, PbTe, Sb2Te3, Bi2Te3, Bi2Se3, Sb, Bi and AgSb2Te4. The main characteristics of metavalent bonding are: i) a much higher cation coordination than that assumed with the 8-N rule; ii) very high Born effective charge and optical dielectric constant as compared to typical covalent materials; iii) high mode Grüneisen parameters of phonons and low wavenumbers of optical phonons as compared to typical covalent materials; and iv) a moderately high electrical conductivity caused by thesmall bandgap which stems from the partial delocalization of electrons between several bonds

Pressure is an important thermodynamic parameter, allowing the increase of matter density by reducing interatomic distances that result in a change of interatomic interactions. In this context, the long range in which pressure can be changed (over six orders of magnitude with respect to room pressure) may induce structural changes at a much larger extent than those found by changing temperature or chemical composition. In this article, we review the pressure-induced phase transitions of most sesquioxides, i.e., A2O3 compounds. Sesquioxides constitute a big subfamily of ABO3 compounds, due to their large diversity of chemical compositions. They are very important for Earth and Materials Sciences, thanks to their presence in our planet’s crust and mantle, and their wide variety of technological applications. Recent discoveries, hot spots, controversial questions, and future directions of research are highlighted.

The appearance in 2012 of some videos in the Estudiantina Komaba channel on YouTube, where we see students from the University of Tokyo performing Venezuelan popular music, executed proficiently in native instruments such as cuatro, harp, maracas and bandola, caused a deep impression in the country, unleashing a series of comments in the media as well as social networks. In this paper we are interested in examining the discourses and arguments people use to justify the exclusivity of the musical manifestations they consider native to their culture, and their astonishment and perplexity with the ability others show to emulate the music they feel belongs to them. In this specific case, the immediacy offered by social networks allows the possibility of observing the phenomenon practically in real time, documenting how these changes and transformations influence deeply the sensibilities of persons and communities. We will try a discursive analysis of the electronic commentaries and the dialogue that arise in the Estudiantina Kobama Youtube’s website, concentrating specifically on topics such as the identity, the nationalism, the autochthonous, the local and the global culture, and the appropriation of cultural assets., La aparición en 2012 de una serie de videos en el canal de la Estudiantina Komaba en Youtube donde se muestra a estudiantes de la Universidad de Tokio interpretando música popular venezolana, ejecutada de la manera más proficiente en instrumentos autóctonos como cuatro, arpa llanera, maracas y bandola, causó una profunda impresión en Venezuela, desatando una serie de comentarios en los medios de comunicación así como en las redes sociales. En este trabajo nos interesa examinar los discursos y argumentos que utilizan las personas para justificar la exclusividad de las manifestaciones musicales que consideran autóctonas de su cultura, y el asombro y perplejidad que muestran frente a la capacidad de otros por emular la música que sienten les pertenece. En el caso que nos ocupa, la inmediatez que ofrecen las redes sociales permite observar el fenómeno prácticamente en tiempo real, documentando cómo estos cambios y transformaciones influyen profundamente en las sensibilidades de la gente y sus comunidades. Ensayaremos para ello un análisis discursivo de los comentarios electrónicos y el diálogo que ellos suscitan en la página de Youtube de la Estudiantina Kobama, concentrándonos específicamente en tópicos como la identidad, lo nacional, lo autóctono, lo local y lo global, la cultura y la apropiación de bienes culturales.

In this research, I publish for the first time, four Venezuelan unpublished pieces for guitar from the 19th century, written by Eloy Galavís (1837-1902). These pieces add up to the practically nonexistent repertory for solo guitar from the 19th century in Venezuela, so that they are a very important input to the history of the guitar in this country. I take advantage of an academic debate between Hugo Quintana and Alejandro Bruzal, which already exceeds twenty years, precisely in relation to the Venezuelan guitar in the 19th century. I reexamine the evidence handled by both musicologists and try to reinterpret it from a new point of view, which will allow to unblock a diatribe already obsolete and with no new elements to offer. Finally, I offer the reproduction of the manuscript sources, as well as a musical edition of these pieces, in order to make them public among musicologists and music players., Publico por primera vez en este trabajo cuatro piezas venezolanas inéditas del siglo XIX para guitarra, del compositor tachirense Eloy Galavís (1837-1902). Estas piezas vienen a sumarse al prácticamente inexistente repertorio para guitarra sola de esa centuria en Venezuela, por lo que constituyen un insumo relevante a la hora de considerar la historia de la guitarra en el país. Aprovechando la extraordinaria oportunidad que me brinda este hecho, dedico buena parte del trabajo a examinar un debate académico entre Hugo Quintana y Alejandro Bruzual que supera ya los veinte años, relativo precisamente a la guitarra decimonónica venezolana. Reexamino las evidencias aportadas por ambos, y procuro su reinterpretación a partir de un nuevo paradigma, que permita destrancar una diatriba que ya luce agotada y sin nuevos elementos que ofrecer. Finalmente, brindo la reproducción de las fuentes manuscritas, así como la edición de las obras, a objeto de hacerlas conocer entre musicólogos e intérpretes.

The spatial distribution of Sr0.5Ba0.5Nb2O6 nanocrystals is analyzed in a borate-based glass-ceramic by a synchrotron hard X-ray nanoimaging tool. Based on X-ray excited optical luminescence, we examined 2D projections of the Nd3+ optically active ions in the Sr0.5Ba0.5Nb2O6 nanocrystals, as well as in the glassy phase where they are embedded. Our findings reveal areas of agglomerations and/or clusters of nanocrystals ascribed to the diffusion coefficients of their constituent elements. They are characterized by high Nd3+ concentrations that may act as heterogeneous agents for the nucleation and growth of these nanocrystals.

In this work we study the pressure behaviour of the orpiment (monoclinic) and anorpiment (triclinic) layered structures of As2S3 by means of ab initio calculations performed within the density functional theory, as part of an ongoing theoretical and experimental joint effort to provide a comprehensive picture of the bonding of this interesting material and the evolution of its structural, electronic, and vibrational properties under pressure. © Published under licence by IOP Publishing Ltd.

Antimony trisulfide (Sb2S3), found in nature as the mineral stibnite, has been studied under compression at room temperature from a joint experimental and theoretical perspective. X-ray diffraction and Raman scattering measurements are complemented with ab initio total-energy, lattice-dynamics, and electronic structure calculations. The continuous changes observed in the volume, lattice parameters, axial ratios, bond lengths, and Raman mode frequencies as a function of pressure can be attributed to the different compressibility along the three orthorhombic axes in different pressure ranges, which in turn are related to the different compressibility of several interatomic bond distances in different pressure ranges. The structural and vibrational properties of Sb2S3 under compression are compared and discussed in relation to isostructural Bi2S3 and Sb2Se3. No first-order phase transition has been observed in Sb2S3 up to 25 GPa, in agreement with the stability of the Pnma structure in Bi2S3 and Sb2Se3 previously reported up to 50 GPa. Our measurements and calculations do not show evidence either for a pressure-induced second-order isostructural phase transition or for an electronic topological transition in Sb2S3. © 2016 American Chemical Society.