First-principles electronic structure of the delafossites ABO(2) (A=Cu, Ag, Au; B=Al, Ga, Sc, In, Y): evolution of d(10)-d(10) interactions

While bonding between d(10) atoms and ions in molecular systems has been well studied, less attention has been paid to interactions between such seemingly closed shell species in extended inorganic solids. In this contribution, we present visualizations of the electronic structures of the delafossites ABO(2) (A = Cu, Ag, Au) with particular emphasis on the nature of d(10)-d(10) interactions in the close packed plane of the coinage metal ion. We find that on going from Cu to Ag to Au, the extent of bonding between A and A increases. However, the structures (in terms of distances) of these compounds are largely determined by the strongly ionic 13,11 0 interaction and for the larger B ions Sc, In and Y, the A atoms are sufficiently well-separated that A-A bonding is almost negligible. We also analyze some interesting differences between Ag and Au, including the larger A-O covalency of the Au. The trends in electronic structure suggest that the Ag and Au compounds are not good candidate transparent conducting oxides. (C) 2002 Editions scientifiques et medicales Elsevier SAS. All rights reserved.

Nucleation-Growth Mode of Cubic-Tetragonal Transition with Coexistence of Phases over a Wide Temperature Interval in the High Temperature Ferroelectric Systems PbTiO3-BiMeO3:Me = Sc , and Zn1/2Ti1/2

Temperature dependent X-ray powder diffraction and dielectric studies have been carried out on tetragonal compositions of (1-x) PbTiO 3(x) BiMeO 3; Me similar to Sc and Zn 1/2 Ti 1/2. The cubic and the tetragonal phases coexist over more than 100 degrees C for 0.70 PbTiO 30.3 Bi ( Zn 1/2 Ti 1/2) O 3 and 0.66 PbTiO 30.34 BiScO 3. The wide temperature range of phase coexistence is shown to be an intrinsic feature of the system, and is attributed to the increase in the degree of the covalent character of the ( Pb +Bi ) O bond with increasing concentration of Bi at the Pb -site. The d-values of the {111} planes of the coexisting phases are nearly identical, suggesting this plane to be the invariant plane for the martensitic type cubic-tetragonal transformation occurring in these systems.

The effect of minor addition of Ni on the microstructural evolution and mechanical properties of suction cast Al-0.14 at. pct Sc binary alloy

Aluminum scandium binary alloys represent a promising precipitation-hardening alloy system. However, the hardness of the binary alloys decreases with the rapid coarsening of Al3Sc precipitate during high-temperature aging. In the current study, we report a new approach to compensate for the loss of mechanical properties by combining rapid solidification with very small ternary addition of transition metal Ni. This addition yields dispersion, and at a critical concentration improves the mechanical properties. We explore additions of a maximum of 0.06 at. pct of Nickel to a binary Al-0.14 at. pct Sc alloy, which yield nickel-rich dispersions. We report two kinds of biphasic dispersions containing AlNi2Sc/Al9Ni2 and alpha-Al/Al9Ni2 phase combinations. The maximum improvement in mechanical properties occurs with the addition of 0.045 at. pct Ni with a yield strength of 239 +/- A 7 MPa for an aging treatment at 583 K (310 A degrees C) for 15 hours. DOI: 10.1007/s11661-013-1624-z (C) The Minerals, Metals & Materials Society and ASM International 2013

SC-FDMA for multiuser communication on the downlink

Single-carrier frequency division multiple access (SC-FDMA) has become a popular alternative to orthogonal frequency division multiple access (OFDMA) in multiuser communication on the uplink. This is mainly due to the low peak-to-average power ratio (PAPR) of SC-FDMA compared to that of OFDMA. Long-term evolution (LTE) uses SC-FDMA on the uplink to exploit this PAPR advantage to reduce transmit power amplifier backoff in user terminals. In this paper, we show that SC-FDMA can be beneficially used for multiuser communication on the downlink as well. We present SC-FDMA transmit and receive signaling architectures for multiuser communication on the downlink. The benefits of using SC-FDMA on the downlink are that SC-FDMA can achieve i) significantly better bit error rate (BER) performance at the user terminal compared to OFDMA, and ii) improved PAPR compared to OFDMA which reduces base station (BS) power amplifier backoff (making BSs more green). SC-FDMA receiver needs to do joint equalization, which can be carried out using low complexity equalization techniques. For this, we present a local neighborhood search based equalization algorithm for SC-FDMA. This algorithm is very attractive both in complexity as well as performance. We present simulation results that establish the PAPR and BER performance advantage of SC-FDMA over OFDMA in multiuser SISO/MIMO downlink as well as in large-scale multiuser MISO downlink with tens to hundreds of antennas at the BS.

Teología, 2001, Tomo XL nº 077 (número completo)

Libros, bibliotecas, control de lecturas e imprentas rioplatenses en los siglos XVI al XVIII / Ernesto J. A. Maeder -- Archivos para la historia de la Iglesia en la Argentina / Ana María Martínez de Sánchez -- Itinerario espiritual y teología de los estados. En diálogo con K. Rahner y H. U. von Balthasar / Virginia Raquel Azcuy -- La dimensión existencial de la esperanza en un poema de Charles Péguy / Cecilia Inés Avenatti de Palumbo -- Tiempo e historia: un aporte bibliográfico al diálogo interdisciplinario / Francisco García Bazán -- Notas bibliográficas

Poner el cuerpo. Mujeres y política estatal en Mari (Siglo XVIII a.c.)

Women and men are subjects defined both by their physical-natural reality and their socio-cultural environment. In this way they are reified, and many such examples can be found throughout history. We are interested in the situation of women in Ancient Mesopotamia, particularly the daughters of Zimrî-Lîm, king of the city of Mari, the archaeological site of Tell Hariri, modern Syria, during the 18th century BC. Zimrî- Lîm made marriages a policy of the state. He himself married foreign women and married their joint daughters to other important kings as well. This marital policy was another, more extended, way of dominion where women were a nexus between Mari and other states. In this paper, we will analyze the roles which were assigned and developed by royal women from a political level via a comprehensive approach. These women are presented generally as political objects, though, in extreme cases also they were taking forward actions as subjects and by it they were visualized as “the other,” the foreigner and, in some cases, the enemy.

Manifesto do Reyno de Portugal : no qual se declara o direito a causas, & o modo, que teve para eximirse da obediencia del Rey de Castella, & tomar a voz do Serenissimo Dom Ioam IV, do nome, & XVIII, entre os Reys verdadeiros deste Reyno

O século XVII foi, para Portugal, um tempo de lutas. Tanto na Europa como no Brasil e na África. Foi, ainda, um período de reorganização jurídica e econômica da sociedade. Para Portugal, o principal acontecimento do século foi a restauração da sua monarquia por Dom João IV, através de uma guerra com a Espanha, em 1640. A guerra com a Espanha foi objeto de relações e notícias, que são as primeiras manifestações do jornalismo em língua portuguesa. O primeiro documento oficial da Restauração foi o “Manifesto do Reyno de Portugal”, que apresenta a argumentação jurídica em favor do que foi , na realidade, um golpe de estado contra a coroa espanhola.

Las élites vascas en el gobierno de la monarquía borbónica : redes sociales, carreras y hegemonía en el siglo XVIII (1700-1746)

815 p. : il., graf.

Labores forestales en Gipuzkoa durante los siglos XVI-XVIII

Número monográfico publicado bajo el título:" Mendia, gizartea eta kultura. Montaña, sociedad y cultura. Montagne, societé et culture".

Euskarazko irakaskuntza Goierrin XVIII. mendeko bigarren erdian

Kolokioaren agiriak : XVIII.mendea Euskal Herrian letretan eta historian: Baionan 2004ko azaroaren 18 eta 19an, Bonnat museoan / Actes du Colloque:Le XVIIIe siècle au Pays Basque à travers les lettres et l'histoire, Musée Bonnat, Bayonne, 18-19 novembre 2004.

Conflictos entre el Corregidor y la Provincia de Guipúzcoa por la jurisdicción sobre los bosques durante el siglo XVIII: lo excepcional del caso guipuzcoano

[ES]Si hasta mediados del siglo XVIII la jurisdicción sobre los bosques guipuzcoanos fue acumulativa y a prevención entre las instituciones provinciales, los alcaldes, el Corregidor y las instituciones de Marina, la Real Cédula de 28 de junio de 1749 inauguró un nuevo período en el que la Provincia la detentó de forma privativa y excluyente, lo que provocó un choque frontal con el Corregidor, quien se resistía a dejar de ejercer sus prerrogativas.