An ab-initio evaluation of the local effective interactions in the superconducting compound Na_0.35CoO_2−1.3H_2O\rm Na\_{0.35} Co O\_2-1.3H\_2O

We used ab-initio quantum chemical methods, treating explicitly the strong correlation effects within the cobalt 3d shell, as well as the screening effects on the effective integrals, for accurately determining on-site and nearest-neighbor (NN) interactions in the $\rm Na\_{0.35} Co O\_2-1.3H\_2O$ superconducting compound. The effective ligand field splitting within the $t\_{2g}$ orbitals was found to be $\delta \sim 300 \rm meV$, the $a\_{1g}$ orbital being destabilized compared to the $e\_g^\prime$ ones. The effective Hund's exchange and Coulomb repulsion were evaluated to $J\_H\sim 280 \rm meV$ and $U\sim 4.1$--$4.8 \rm eV$. The NN hopping parameters were determined within the three $t\_{2g}$ orbitals and found to be of the same order of magnitude as the $t\_{2g}$ ligand field splitting, supporting the hypothesis of a three band model for this system. Finally we evaluated the NN effective exchange integral to be antiferromagnetic and $J=-66 \rm meV$

An ab-initio evaluation of the local effective interactions in the NaxCoO2\rm Na_{x} Co O_2 familly

We used quantum chemical ab initio methods to determine the effective parameters of Hubbard and $t-J$ models for the $\rm Na_{x}CoO_2$ compounds (x=0 and 0.5). As for the superconducting compound we found the $a_{1g}$ cobalt orbitals above the $e_g^\prime$ ones by a few hundreds of meV due to the $e_g^\prime$--$e_g$ hybridization of the cobalt $3d$ orbitals. The correlation strength was found to increase with the sodium content $x$ while the in-plane AFM coupling decreases. The less correlated system was found to be the pure $CoO_2$, however it is still strongly correlated and very close to the Mott transition. Indeed we found $U/t\sim 15$, which is the critical value for the Mott transition in a triangular lattice. Finally, one finds the magnetic exchanges in the $\rm CoO_2$ layers, strongly dependant of the weak local structural distortions

The crucial importance of the t2gt_{2g}--ege_g hybridization in transition metal oxides

We studied the influence of the trigonal distortion of the regular octahedron along the (111) direction, found in the $\rm CoO_2$ layers. Under such a distortion the $t_{2g}$ orbitals split into one $a_{1g}$ and two degenerated $e_g^\prime$ orbitals. We focused on the relative order of these orbitals. Using quantum chemical calculations of embedded clusters at different levels of theory, we analyzed the influence of the different effects not taken into account in the crystalline field theory; that is metal-ligand hybridization, long-range crystalline field, screening effects and orbital relaxation. We found that none of them are responsible for the relative order of the $t_{2g}$ orbitals. In fact, the trigonal distortion allows a mixing of the $t_{2g}$ and $e_g$ orbitals of the metallic atom. This hybridization is at the origin of the $a_{1g}$--$e_g^\prime$ relative order and of the incorrect prediction of the crystalline field theory

Trimer Formation and Metal-Insulator Transition in Orbital Degenerate Systems on a Triangular Lattice

As a prototypical self-organization in the system with orbital degeneracy, we theoretically investigate trimer formation on a triangular lattice, as observed in LiVO2. From the analysis of an effective spin-orbital coupled model in the strong correlation limit, we show that the previously-proposed orbital-ordered trimer state is not the lowest-energy state for a finite Hund's-rule coupling. Instead, exploring the ground state in a wide range of parameters for a multiorbital Hubbard model, we find an instability toward a different orbital-ordered trimer state in the intermediately correlated regime in the presence of trigonal crystal field. The trimer phase appears in the competing region among a paramagnetic metal, band insulator, and Mott insulator. The underlying mechanism is nesting instability of the Fermi surface by a synergetic effect of Coulomb interactions and trigonal-field splitting. The results are compared with experiments in triangularlattice compounds, LiVX2 (X=O, S, Se) and NaVO2.Comment: 4 pages, 4 figures, accepted for publication in J. Phys. Soc. Jp

Trichology: A Study of Hair and its Uses as Trace Evidence

The purpose of this research was to study the characteristics of hair for the use as trace evidence. These characteristics are being used to add validity and reliability from the use of hair to confirm the identity of a person. Eight different humans and one dog hair samples were collected and compared to identify a fictional suspect. All of the hairs, including the primary suspect’s, were collected from a fictional crime scene. The characteristics were analyzed using a polarized microscope to microscopically compare the hairs and a ForensicGEM® DNA Extraction Kit, ZyGEM was used to extract DNA from the samples. The extracted DNA was then forwarded to the Biology Department at Colorado State University for sequencing. The hypothesis was that a positive identification would be made using this combination of microscopy and mitochondrial DNA extraction

FROM TOTAL INSTITUTION TO EXTITUTION? Discussions on the future of monastic life in the Benedictine women’s monasteries of Catalonia (Spain)

On the 50th anniversary of the creation of the Federation of Benedictine Women’s Monasteries of Catalonia (Spain), the five monasteries represented are discussing the following question: what will monastic life be like in the future? This question is added to the debate about “new forms of monasticism”, “urban monastic life” and, in a more general sense, to the modernisations and “the opening up” of the precepts and practices of monastic life at this time. Faced with the ambitious monastic questioning, the author responds with five deliberately provocative debates developed out of a consideration of various chapters of the Rule of St. Benedict that raise profound questions when it comes to responding to the question presented here. Having described these five debates, by way of a summary, the article presents three ideal types of monastery in relation to the current processes of deinstitutionalisation that represent, in an overall way, three provisional responses and serve as a focus for the question discussed here.Con motivo del 50 aniversario de la creación de la Federación de Monasterios Benedictinos de Cataluña, los cinco monasterios miembros se plantean la siguiente pregunta: ¿cómo será la vida monacal en el futuro? Esta cuestión se enmarca en los debates sobre las “nuevas formas de monaquismo”, “monaquismo urbano”, y, de forma más general, en la puesta al día de los preceptos y las prácticas de la vida monástica hoy. Ante la ambiciosa pregunta de los monasterios, el autor responde con cinco debates que se desarrollan partiendo de la Regla de San Benito. Estos cinco debates propuestos a las comunidades monásticas en una metodología cercana a la investigación —acción, desembocan a modo de resumen en la propuesta de tres modelos ideales de vida monástica en relación con los procesos de desinstitucionalización y extitucionalización que viven los mismos. Estos tres modelos ideales representan la respuesta provisional a los debates y a la vez son un nuevo punto de partida del debate con los monasterios sobre su realidad

Human Trafficking and Its Evolution into Cyberspace: How Has Technology Transformed Human Trafficking Over Time?

Over the past few years, with the rise of technology, human trafficking has transformed into one of the largest clandestine crimes globally. Though the relationship between human trafficking and technology has gained attention over recent years, the empirical research on this topic is still underdeveloped. As such, the relationship between technological developments and the rise of human trafficking remains unanswered. Within this frame of reference, this research aims to explore this relationship to better understand how human trafficking has flourished in cyberspace and is beginning to depend on technological advancements for predation by using a content analysis of newspaper articles. After outlining key terms concerning human trafficking in the context of sex trafficking, the present research then examines articles overtime to see the progression of human trafficking in cyberspace. News articles were chosen because they serve as the primary source of information about historical and current events

Italie et Italiens d’aujourd’hui dans le cinéma soci(ét)al d’Ivano De Matteo

Parmi les réalisateurs italiens dont les filmographies s’inscrivent aujourd’hui dans la veine d’un « nouveau » cinéma engagé figure le Romain Ivano De Matteo, auteur d’une trilogie « soci(ét)ale » : La bella gente (tourné en 2009 mais sorti en Italie durant l’été 2015), Gli equilibristi (2012) et I nostri ragazzi (2014) sont trois versions d’un rapport difficile à l’Autre, au Monde, à la société. Construits selon un même schéma global, ils sont la radiographie d’une société malade : dans la diégèse, l’équilibre établi se brise à l’arrivée d’un élément extérieur et inattendu, produit directement ou indirectement par la société. De Matteo insère dans ces trois volets la nécessité d’un questionnement sur le « Je » ; la construction formelle et l’écriture filmique sont elles aussi au service du propos, dans une démarche visant à impliquer puis responsabiliser le récepteur. Objets de critique « soci(ét)ale », à la fois films d’auteur(s) et de divertissement, les films du corpus retenu permettent une réflexion sur le monde à partir de procédés propres au cinéma dit « engagé ».Tra i registi italiani le cui filmografie si iscrivono oggi nel filone di un « nuovo » cinema impegnato c’è il romano Ivano De Matteo, autore di una trilogia « soci(et)ale » : La bella gente (girato nel 2009 ma uscito in Italia solo durante l’estate 2015), Gli equilibristi (2012) e I nostri ragazzi (2014) sono tre versioni di un rapporto difficile con l’Altro, con il Mondo, con la società. Costruiti secondo uno stesso schema globale, sono la radiografia di una società malata : nella diegesi, l’equilibrio si rompe con l’introduzione di un elemento esterno e inaspettato, prodotto direttamente o indirettamente dalla società. De Matteo inserisce in queste tre parti la necessità dell’interrogare il proprio « io » ; la costruzione formale e la scrittura filmica sono anche al servizio del discorso, in un progetto che mira a coinvolgere e responsabilizzare lo spettatore. Oggetti di critica « soci(et)ale », nel contempo film d’autore(i) e di divertimento, i film del corpus permettono una riflessione sul mondo a partire da processi relativi al cinema cosiddetto « impegnato »