Metallic compounds of scandium-tellurium and related systems

Research contributions from our group have evinced significant progress in the solid-state chemistry of the rare-earth metal halides. This thesis presents results of the first extension of this progress into the scandium-tellurium and related ternary systems. The first evidence for the existence of metal-rich compounds in this system was the synthesis of Sc2Te. The internal metal-bonded features of the structure are double quasi-infinite chains of trans-edge-sharing metal octahedra, further augmented on each end by square-pyramids down the chain. These scandium chains have a blade-like shape and are spaced apart by tellurium atoms and a scandium zigzag chain. A second metal-rich compound was uncovered in Sc8Te3. Chains of trans-edge-sharing octahedra are again featured in much of the metal framework, but condensed into 2D sheets. In the Y8Te3 analog there is apparent disorder on some of the internal metal positions within the chains. The metal-richest compound synthesized in the scandium-tellurium system was Sc9Te 2. A higher degree of metal aggregation forms in four trans-edge-sharing metal octahedra chains condensed into 3 x 3 blocks, and linked together to form much thicker 2D sheets compared to Sc8Te3. Interesting distortions were analyzed with relationship to higher symmetry structures. The insertion of later transition metals into the earlier transition-metal framework results in the formation of the compounds Sc5Ni 2Te2, Sc6MTe2 (M = Mn, Fe, Co, Ni), Y5M2Te2 (M = Fe, Co, Ni) and the corresponding hydride, Y5Ni2TeH0.41(1). These compounds contain diverse sheet and columnar metal frameworks. Structural interrelationships among the many known ternary compounds are analyzed. The reaction of small amounts of aluminum into the scandium-tellurium systems revealed new substitution chemistry. The systems Sc5BxB\u27 3-x (B = Al or Ga; B\u27 = Sn, Sb or Te) contained varied amounts of the triel elements (B) substituted on the same sites for either the tetrel, pnictide or chalcogenide (B\u27), respectively. Analysis of the synthesis and structure of these compounds was used to incrementally improve the continuously evolving scientific answers about recurring structural features and structure/property relationships in solids

Making arm movements within different parts of space: dynamic aspects in the primate motor cortex

The activity of 176 individual cells in the arm area of motor cortex (areas 4 and 6) was studied while monkeys made arm movements of similar direction within different parts of extrapersonal space. The behavioral paradigm used was a 3-dimensional reaction-time task aimed at dissociating the direction of movement, which remained similar across the work space, from the patterns of muscular activity and the angular joint excursions necessary to perform these movements. In agreement with other studies (Georgopoulos et al., 1982; Schwartz et al., 1988), we found that, within a given part of space, the activity of 169 (96.0%) cells studied increased most for a given preferred direction and less for other directions of movement. This change was graded in an orderly fashion. We further analyzed the orientation in space of the cells' preferred directions under the differing conditions of the task. We found that, as movements with similar trajectories were made within different parts of space, the cells' preferred directions changed spatial orientation. This change was of different magnitudes for different cells, but at the level of the population, it followed closely the changes in orientation of the arm necessary to perform the movements required by the task. Movement population vectors (Georgopoulos et al., 1983, 1986, 1988) computed from cell activity proved to be good predictors of movement direction regardless of where in space the movements were performed. These results indicate that motor cortical cells can code direction of movement in a way which is dependent on the position of the arm in space. The data are discussed in relation to the existence of mechanisms which facilitate the transformation between extrinsic and intrinsic coordinates. These transformations are necessary to perform arm movements to visual targets in space

Ariel - Volume 4 Number 2

Editors David A. Jacoby Eugenia Miller Tom Williams Associate Editors Paul Bialas Terry Burt Michael Leo Gail Tenikat Editor Emeritus and Business Manager Richard J. Bonnano Movie Editor Robert Breckenridge Staff Richard Blutstein Mary F. Buechler Steve Glinks Len Grasman Alice M. Johnson J. D. Kanofsky Tom Lehman Dave Mayer Bernie Odd

Literární reflexe cestování časem v americké literatuře 40. a 50. let

Katedra anglického jazyka a literaturyPedagogická fakultaFaculty of Educatio

UVC Dose Mapping by Mobile Robots

As infeções adquiridas em ambientes hospitalares são um problema persistente e crescente e a sua prevenção envolve a desinfeção de áreas e superfícies. A necessidade de métodos de desinfeção eficazes aumentou muito em consequência da pandemia de Covid-19. Um método eficaz é a utilização de exposição UVC porque a radiação UVC é absorvida pelos ácidos nucleicos e, portanto, é capaz de inativar microrganismos. Este método também traz muitas vantagens quando comparado com os métodos tradicionais de desinfeção. A desinfeção UVC pode ser realizada por equipamentos fixos que têm de ser deslocados de um local para outro de modo a desinfetar toda uma área, ou por um equipamento móvel autónomo que requer intervenção humana mínima para desinfetar completamente um ambiente. Esta dissertação foca em robôs móveis que desinfetam um ambiente utilizando radiação UVC. Estes robôs móveis são capazes de se mover autonomamente enquanto mapeiam o ambiente à sua volta e simultaneamente o desinfetam. Os robôs mantêm registo da dose aplicada a cada área do ambiente de modo a construir um mapa da dose e diferenciar as áreas completamente desinfetadas das que não o estão. Esta solução tem a vantagem de o robô realizar a desinfeção UVC sem necessitar de parar em cada área nem ter conhecimentos prévios sobre o ambiente. A validação desta solução foi realizada utilizando o rviz, uma ferramenta do Robot Operating System (ROS), e a LiDAR Camera L515. A câmara foi utilizada para recolher a informação necessária para a criação do mapa do ambiente e o rviz foi utilizado para visualizar o mapa da dose.Hospital-acquired infections are a persistent and increasing problem and their prevention involves disinfecting areas and surfaces. The necessity for effective disinfection methods has highly increased in consequence of the Covid-19 pandemic. An effective method is using UVC exposure because UVC radiation is absorbed by nucleic acids and, therefore, is able to inactivate microorganisms. This method also brings many advantages when compared with traditional disinfection methods. UVC disinfection can be performed by fixed equipments that have to be moved from place to place to disinfect an entire area, or by an autonomous mobile equipment that requires minimal human intervention to completely disinfect an environment. This dissertation is focused on mobile robots that disinfect an environment using UVC radiation. These mobile robots are able to move autonomously while mapping the surrounding environment and simultaneously disinfect it. The robots keep track of the dose applied to each area of the environment in order to build a dose map and differentiate areas that are completely disinfected from those that are not. This solution has the advantage of the robot performing UVC disinfection without needing to stop in each area nor having previous knowledge of the environment. The validation of this solution was performed using rviz, a Robot Operating System (ROS) tool, and the LiDAR Camera L515. The camera was used to capture the necessary information for creating the map of the environment and rviz was used to visualize the dose map

Factores tecnológicos que afectan a las propiedades del queso, rendimiento y lactosuero generado a partir de leche cruda de oveja durante la producción de queso en pequeñas queserías rurales

258 p.El objetivo principal de esta Tesis Doctoral fue evaluar el impacto de las condiciones tecnológicas utilizadas durante la elaboración de queso en las características de los gránulos de cuajada, composición del lactosuero, y las propiedades y rendimiento del queso a lo largo de la época de producción de queso de oveja (Idiazabal) en pequeñas queserías rurales. Para ello se llevaron a cabo tres tipos de estudios: estudio observacional durante 2 años en ocho queserías rurales, estudio de intervención en dos queserías rurales, y estudio experimental a escala de laboratorio. Se investigó de forma específica el efecto de los parámetros tecnológicos utilizados durante el corte y recalentamiento de la cuajada, realizando un análisis profundo del tamaño, forma y distribución de los granos de cuajada generados, así como una caracterización de la microestructura, y los cambios que ocurren durante el proceso de elaboración en los gránulos de cuajada, y en el queso obtenido. Los resultados de la Tesis Doctoral muestran interesantes relaciones entre los parámetros tecnológicos utilizados y la composición y propiedades de la cuajada y el queso, así como con los valores de rendimiento y pérdidas de compuestos en el lactosuero. Así mismo, los resultados confirman que el proceso de elaboración que se realiza actualmente en las pequeñas queserías rurales podría mejorarse adaptando algunos de los parámetros tecnológicos estudiados y sin modificación de las propiedades del queso. La información aportada es especialmente útil para que los elaboradores puedan ajustar los parámetros tecnológicos en sus instalaciones, contribuyendo así a la sostenibilidad tanto económica como ambiental de las pequeñas queserías rurales

Association of Christians in the Mathematical Sciences Proceedings 2019

The conference proceedings of the Association of Christians in the Mathematical Sciences biannual conference, May 29-June 1, 2019 at Indiana Wesleyan University

Textual Entanglements: A Performative Approach towards Digital Literature

This thesis conducts a critical investigation into digital literature—a genre of literary expression that is integrated with, and articulated using, digital computing systems and infrastructures. Specifically, it presents a framework for evaluating the expressive capacities of this genre as it relates to particular conceptions of knowledge-making in the contemporary technocultural environment. This framework reveals how the generation of critical knowledge concerning digital literature, as crystallised through a reader’s material engagements with specific works, enacts a ‘performative’ conception of knowing and being, in which the observable world is treated as emerging in the real time of practice—as being articulated through the entanglement of human and nonhuman agencies, rather than existing as a fixed array of passive, unchanging primitives. Digital literature is presented subsequently as a model of this greater performative vision—as a means of evaluating the structures and processes that manifest it, particularly within digital systems, and for assessing its practical and political implications for art and culture more broadly. In so doing, this thesis aims to justify the value of engaging digital literature from a standpoint that is more expressly political, contending not only that these texts are revealing of key processes shaping digital activities, artefacts, and environments, but are enacting alternative vectors of thought and practice concerning them.AHR