980 resultados para Hudson


Relevância:

10.00% 10.00%

Publicador:

Resumo:

In this work, we study the effect of doping depth profile on the photocatalytic and surface properties of TiO(2) films. Two thin film layers of TiO(2) (200 nm) and Co (5 nm), respectively, were deposited by physical evaporation on glass substrate. These films were annealed for 1 s at 100 and 400 A degrees C and the Co layer was removed by chemical etching. Atomic force microscopy (AFM) phase images showed changes in the surface in function of thermal treatment. The grazing-incidence X-ray fluorescence (GIXRF) measurements indicated that the thermal treatment caused migration of Co atoms to below the surface, the depths found were between 19 and 29 nm. The contact angle showed distinct values in function of the doped profile or Co surface concentration. The UV-vis spectra presented a red shift with the increasing of thermal treatment. Photocatalytical assays were performed by methylene blue discoloration and the higher activity was found for TiO(2)-Co treated at 400 A degrees C, the ESI-MS showed the fragments formed during the methylene blue decomposition.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In order to evaluate the interactions between Au/Cu atoms and clean Si(l 11) surface, we used synchrotron radiation grazing incidence X-ray fluorescence analysis and theoretical calculations. Optimized geometries and energies on different adsorption sites indicate that the binding energies at different adsorption sites are high, suggesting a strong interaction between metal atom and silicon surface. The Au atom showed higher interaction than Cu atom. The theoretical and experimental data showed good agreement. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In this work, we studied the photocatalytic and the structural aspects of silicon wafers doped with Au and Cu submitted to thermal treatment. The materials were obtained by deposition of metals on Si using the sputtering method followed by fast heating method. The photocatalyst materials were characterized by synchrotron-grazing incidence X-ray fluorescence, ultraviolet-visible spectroscopy, X-ray diffraction, and assays of H(2)O(2) degradation. The doping process decreases the optical band gap of materials and the doping with Au causes structural changes. The best photocatalytic activity was found for thermally treated material doped with Au. Theoretical calculations at density functional theory level are in agreement with the experimental data.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We study the photoassociation of Bose-Einstein condensed atoms into molecules using an optical cavity field. The driven cavity field introduces a dynamical degree of freedom into the photoassociation process, whose role in determining the stationary behavior has not previously been considered. The semiclassical stationary solutions for the atom and molecules as well as the intracavity field are found and their stability and scaling properties are determined in terms of experimentally controllable parameters including driving amplitude of the cavity and the nonlinear interactions between atoms and molecules. For weak cavity driving, we find a bifurcation in the atom and molecule number occurs that signals a transition from a stable steady state to nonlinear Rabi oscillations. For a strongly driven cavity, there exists bistability in the atom and molecule number.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Electromagnetically induced transparency (EIT) is an important tool for controlling light propagation and nonlinear wave mixing in atomic gases with potential applications ranging from quantum computing to table top tests of general relativity. Here we consider EIT in an atomic Bose-Einstein condensate (BEC) trapped in a double-well potential. A weak probe laser propagates through one of the wells and interacts with atoms in a three-level Lambda configuration. The well through which the probe propagates is dressed by a strong control laser with Rabi frequency Omega(mu), as in standard EIT systems. Tunneling between the wells at the frequency g provides a coherent coupling between identical electronic states in the two wells, which leads to the formation of interwell dressed states. The macroscopic interwell coherence of the BEC wave function results in the formation of two ultranarrow absorption resonances for the probe field that are inside of the ordinary EIT transparency window. We show that these new resonances can be interpreted in terms of the interwell dressed states and the formation of a type of dark state involving the control laser and the interwell tunneling. To either side of these ultranarrow resonances there is normal dispersion with very large slope controlled by g. We discuss prospects for observing these ultranarrow resonances and the corresponding regions of high dispersion experimentally.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper uses Glister's interpretation of digital literacy whilst acknowledging that a computer is not the only means for the delivety of digital texts. I will explore how we can support student teachers to develop understandings about the teaching in the middle years in order to work with students in schools to successfully read digital texts, create digital texts, search, fmd and use information in the digital world and to become critical users of digital texts. Students in the middle years of schooling are facing increasingly sophisticated literacy demands of new technologies that go well beyond that of the traditional printed page as they interact with information communicated through a range of digital media both inside and outside of school. At best new technologies can open doors to students for researching and accessing a world far beyond their own environment, empowering them to direct and control their own learning and produce quality work.

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Resumo:

During the late eighteenth and early nineteenth centuries management accounting practices were transferred from London counting houses to the British North American fur trade. This transfer involved a set of practices that was more effective for implementing the strategy being pursued at the time than the set used with the previous strategy. London counting houses had developed management accounting practices to facilitate their backward integration strategies with America and the West Indies. Pivotal to this development was the requirement for sub-unit accountability and responsibility.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Purpose – Sir George Simpson, the Governor of the Hudson's Bay Company (HBC) from 1821 to his death in 1860, was the subject of numerous biographical works that described various facets of the man including his managerial abilities, literary prowess, physical stamina, abundant energy, extensive art collection and ethnological specimens. Two related aspects of his outstanding management style have been overlooked: the genesis of his management style and where it can be placed in the evolution of management practices during the 19th century.

Design/methodology/approach – Primary data from the Hudson's Bay Company archives plus secondary sources.

Findings – Simpson's management abilities came from his grammar school education and his apprenticeship to a counting house. More importantly, it can be attributed to his association with his mentor Andrew Wedderburn, his dedication to the HBC, and his high level of physical and intellectual energy. His information intensive management style was also a significant precursor to systematic management, which occurred later in the 19th century.

Research limitations/implications – Future research should examine other examples of the evolution of management during the 19th century, particularly the transition from sub-unit accountability to systematic management.

Originality/value – The paper emphasizes the importance of managers in making management systems work.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A literature review revealed no evidence-based guidelines specific to managing diabetes in the context of palliative care. The purpose of the current project was to describe the management practices of doctors and nurses caring for people with diabetes and advanced disease. Palliative care doctors, palliative care nurses, endocrinologists, and diabetes nurse educators participated in this study. A two-phase project was undertaken: 1) two focus groups, and 2) a cross-sectional survey using a self-completed questionnaire. The focus group and questionnaire data identified that doctors and nurses used a range of practices and blood glucose testing frequencies to control blood glucose based on experience and not according to a robust evidence base. Implications for practice include the importance of collaboration between diabetes and palliative care specialists, and the need to develop clinical management guidelines.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This white paper explores the role of organisational culture in either supporting or constraining the success of women in the workplace and investigates the benefits of gender diversity and what organisations can do to prevent ongoing gender bias.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Explores the impact of globalization upon citizenship, with special reference to the transitional challenge that globalisation poses. It also examines how different concepts, theories and practices of citizenship are evolving in response to globalisation and that seek to modify its impact. Australian authors.