106 research outputs found

    A Hemispherical Contact Model for Simplifying 3D Occlusal Surfaces

    Get PDF
    Statement of problem Currently, dental articulators can recreate mandibular movements and occlusal contacts. However, whether virtual articulators can also provide information about occluding dental surfaces, functional movements, and the mandibular condyles is unclear. Purpose The purpose of this in vitro study was to evaluate the occluding surfaces on dental casts obtained from a patient and approximate them to a hemispherical contact model. Both models were tested by digitizing the Dentatus ARL dental articulator. Material and methods A combination of photogrammetry and structure from motion methods were used to scan a Dentatus ARL articulator and representative dental casts. Using computer-aided engineering and finite element analysis, contact points and action vectors to the forces on occluding surfaces and condyles were obtained for cast and hemispherical models. This experiment was performed using centric occlusion and 3 different condylar inclinations. The Kruskal-Wallis 1-way analysis of variance on ranks test was used to allow all pairwise comparisons between condylar inclination and mechanical action vector values in each location (α=.05). Results Action vectors from the cast model and each location of the hemispherical model were calculated to show the mechanical consequences and the similarity among models. Overall, no significant differences were observed for action vectors (A20 versus A40 versus A60) at each location (dental cast/hemisphere, right condylar, and left condylar) in the analysis of dental casts and the hemisphere model (.382≤P≤.999). Conclusions This study provided graphical information that may assist the dental professional in determining which occlusal contacts should be modified to attain condylar and balanced centric occlusion

    Understanding the open circuit voltage in organic solar cells on the basis of a donor-acceptor abrupt (p-n++) heterojunction

    Get PDF
    By using electrical characterization and classical solid state semiconductor device theory, we demonstrate that the open circuit voltage (V oc ) in organic solar cells based on non-intentional doped semiconductors is fundamentally limited by the built-in potential (V bi ) originated at a donor-acceptor abrupt (p-n ++ ) heterojunction in case of selective contacts. Our analysis is validated using P3HT:PCBM devices fabricated in our research group. We also demonstrate that such a result can be generalized using data already reported in literature for fullerene-based solar cells. Finally, we show that the dependence of V oc on the device contacts can be understood in terms of the potential barriers formed by the Fermi level alignment of semiconductors at the heterojunction and at the Schottky junctions

    Coloquio Nacional a diez años de la Ley Federal de Educación

    Get PDF
    Organizado por la Escuela de Ciencias de la Educación, la Secretaría de Extensión de la Facultad de Filosofía y Humanidades de la Universidad Nacional de Córdoba y el Equipo de Investigación de la Cátedra de Organización y Administración Educacional, se desarrolló un coloquio que nucleó a 250 investigadores de Universidades e Institutos de Formación Docente de todo el país, con el objetivo de realizar un balance de la implementación de la reforma educativa iniciada con la Ley Federal de Educación (LFE). Al cumplirse diez años de su sanción y poniendo entre signos de interrogación el lema que acompañó a la reforma: Mejor Educación para todos se expusieron gran cantidad de trabajos referidos a su implementación en las jurisdicciones. En general las presentaciones revistieron un tono crítico respecto a varias cuestiones básicas de la Ley y la Reforma

    Soluciones creativas de intervención

    Get PDF
    En este proyecto se trabajó con empresas socialmente responsables en la creación de vínculos con comunidades, organización y otros ámbitos de la sociedad para mejorar su entorno. Esto se logró a través de la creación de estrategias de comunicación e intervención social, con lo cual la empresa logra obtener un beneficio de posicionamiento y, a la vez, produce un beneficio social tangible

    Ethical preferences for influencing superiors: A 41-society study

    Get PDF
    With a 41-society sample of 9990 managers and professionals, we used hierarchical linear modeling to investigate the impact of both macro-level and micro-level predictors on subordinate influence ethics. While we found that both macro-level and micro-level predictors contributed to the model definition, we also found global agreement for a subordinate influence ethics hierarchy. Thus our findings provide evidence that developing a global model of subordinate ethics is possible, and should be based upon multiple criteria and multilevel variables

    Revista de Vertebrados de la Estación Biológica de Doñana

    Get PDF
    Página 298 con error de impresiónEstudio cariológico en dos especies de Serránidos del Mediterráneo (Peces: PerciformesRelaciones morfométricas de Atherina boyeri Risso (Pisces: Atherinidae) de la laguna de Zoñar (Córdoba, España)Contribución al conocimiento de la biometríay osteología de Barbus barbus bocagei, Steindachner, 1866 (Pisces: CyprinidaeLa actividad de la salamandra, Salamandra salamandra (L.), en Galicia.Estudios sobre el sapo corredor (Bufo calamita) en el Sur de España.1. BiometríaEstudios sobre el sapo corredor (Bufo calamita) en el Sur de España. II. AlimentaciónBiología de la reproducción de Rana iberica Boulenger 1879 en zonas simpátridas con Rana temporaria Linneo, 1758Nuevos datos sobre la distribución geográfica de Lacerta monticola cantabrica Mertens, 1929. (Sauria, lacertidae).Datos sobre Lacerta monticola Boulenger, 1905 (Saurio: lacertidae)en el oeste del Sistema Central.Nueva especie de Anolis (lacertilia, Iguanidae) para CubaEtograma cuantificado del cortejo en Falco naumannOntogénesis del comportamiento predador en Falco naumanniContaminación xenobiótica del Parque Nacional de Doñana. 1. Residuos de insecticidas organoclorados, bifenilos policlorados y mercurio en anseriformes y gruiformesReproducción del críalo (Clamator glandarius) en Sierra Morena CentraNidificación de Picus viridis en taludes de arcilla en Ramblas de Guadix (Granada)Comportamiento del calamón Porphyrio porphyrio (Linnaeus, 1758) en Doñana, Marismas del GuadalquiviBiología y ecología de la malvasía (Oxyura leucocephala) en Andalucía.On the differential diet of Carnivora in islands:a method for analysing it and a particular case.Notas sobre la distribución pasada y actual del meloncillo Herpestes ichneumon (L.) en la Península IbéricaEstructuración de las interacciones en una camada de lobos (Canís lupus)Nuevos datos sobre la distribución del Cottus gobio L. (pisces, cottidae) en EspañaSobre la alimentación de Callopistes maculatus (Reptilia,teiidaeObservación de Lacerta lepida depredando un nido de Alectoris rufaNueva cita del galápago leproso Mauremys leprosa (Scheigger, 1812) en los pirineosPrimera cita de Psammodromus hispanicus (Fitzinger) para GaliciaSobre la presencia de Gallotia (=Lacerta) atlantica (Peters y Doria, 1882) en Gran CanariaNota sobre las Lacerta monticola Boulenger, 1905 de las zonas del norte de GaliciaPrimeras notas herpetológicas de la provincia de Soria.Datos sobre selección de hábitat y ecología alimenticia del porrón pardo (Aythya nyroca)Probable nueva área de cría del pechiazul (Luscinia svecica cyanecula) en el sistema central. PerisPredación de Falco peregrinus y Falco subbuteo sobre quirópterosResultados de la producción de Oxyura leucocephala en el año 1981 en las lagunas de Zóñar y el rincónAnálisis de la dieta de Tyto alba en un medio árido antropógeno de los alrededores de Almería¿Son Eudocimus ruber y E. albus distintas especies?EL Estornino pinto (Sturnus vulgaris) en Canarias: nueva especie nidifiante en el archipiélagoDatos sobre la alimentación otoñal del cárabo (Strix aluco) en la sierra de CádizObservación primaveral de rapaces y otras aves en el páramo del estado de Mérida (Venezuela).Murciélago hematófago (Desmodus rotundus) parasitando a un chigüire (Hidrochoerus hydrochaeris)Observaciones sobre la reproducción del zacatuche o teporinho Romerolagus diazi (Mammalia: lagomorpha)Estudio electroforético de hemoglobinas y esterasas sanguíneas en Rhinolophus ferrumequinum (Chiroptera: rhinolophidae) y de hemoglobinas en Tadaria taeniotis (chiroptera: molossidae)Peer reviewe

    La gestión de centros de enseñanza obligatoria en Iberoamerica - RedAGE

    Get PDF
    La presente aportación recoge la visión de los especialistas de once países iberoamericanos sobre aspectos de gestión relevantes en los niveles de la educación obligatoria. Muchas de las aportaciones se pueden calificar de ensayos, otras de investigaciones y algunas de análisis críticos sobre un aspecto considerado significativo. Su realización se vincula al encuentro de especialistas realizado durante los días 8 al 10 de junio de 2009 en el marco de la Red de Apoyo a la Gestión Educativa (Red AGE). Los representantes de las organizaciones miembro presentaron y debatieron durante el mismo documentos sobre la situación actual de la gestión educativa en sus respectivos países, que constituyen la base sobre la que se han realizado las aportaciones definitivas que recoge el presente texto

    A Twenty-First Century Assessment of Values Across the Global

    Get PDF
    This article provides current Schwartz Values Survey (SVS) data from samples of business managers and professionals across 50 societies that are culturally and socioeconomically diverse. We report the society scores for SVS values dimensions for both individual- and societallevel analyses. At the individual-level, we report on the ten circumplex values sub-dimensions and two sets of values dimensions (collectivism and individualism; openness to change, conservation, self-enhancement, and self- transcendence). At the societal-level, we report on the values dimensions of embeddedness, hierarchy, mastery, affective autonomy, intellectual autonomy, egalitarianism, and harmony. For each society, we report the Cronbach’s a statistics for each values dimension scale to assess their internal consistency (reliability) as well as report interrater agreement (IRA) analyses to assess the acceptability of using aggregated individual level values scores to represent country values. We also examined whether societal development level is related to systematic variation in the measurement and importance of values. Thus, the contributions of our evaluation of the SVS values dimensions are two-fold. First, we identify the SVS dimensions that have cross-culturally internally reliable structures and withinsociety agreement for business professionals. Second, we report the society cultural values scores developed from the twenty-first century data that can be used as macro-level predictors in multilevel and single-level international business research

    The 2017 Terahertz Science and Technology Roadmap

    Get PDF
    Science and technologies based on terahertz frequency electromagnetic radiation (100GHz-30THz) have developed rapidly over the last 30 years. For most of the 20th century, terahertz radiation, then referred to as sub-millimeter wave or far-infrared radiation, was mainly utilized by astronomers and some spectroscopists. Following the development of laser based terahertz time-domain spectroscopy in the 1980s and 1990s the field of THz science and technology expanded rapidly, to the extent that it now touches many areas from fundamental science to “real world” applications. For example THz radiation is being used to optimize materials for new solar cells, and may also be a key technology for the next generation of airport security scanners. While the field was emerging it was possible to keep track of all new developments, however now the field has grown so much that it is increasingly difficult to follow the diverse range of new discoveries and applications that are appearing. At this point in time, when the field of THz science and technology is moving from an emerging to a more established and interdisciplinary field, it is apt to present a roadmap to help identify the breadth and future directions of the field. The aim of this roadmap is to present a snapshot of the present state of THz science and technology in 2016, and provide an opinion on the challenges and opportunities that the future holds. To be able to achieve this aim, we have invited a group of international experts to write 17 sections that cover most of the key areas of THz Science and Technology. We hope that The 2016 Roadmap on THz Science and Technology will prove to be a useful resource by providing a wide ranging introduction to the capabilities of THz radiation for those outside or just entering the field as well as providing perspective and breadth for those who are well established. We also feel that this review should serve as a useful guide for government and funding agencies
    corecore