Chemisorption and reactivity of furan on Pd{111}

XPS, HREELS, ARUPS and Delta phi data show that furan chemisorbs non-dissociatively on Pd{111} at 175 K, the molecular plane being significantly tilted with respect to the surface normal. Bonding involves both the oxygen lone pair and significant a interaction with the substrate. The degree of decomposition that accompanies molecular desorption is a strong function of coverage: similar to 40% of the adsorbate desorbs molecularly from the saturated monolayer. Decomposition occurs via decarbonylation to yield COa and H-a followed by desorption rate limited loss of H-2 and CO. It seems probable that an adsorbed C3H3 species formed during this process undergoes subsequent stepwise dehydrogenation ultimately yielding H-2 and C-a.

Long-Range Lateral Dopant Diffusion in Tungsten Silicide Layers

Novel diode test structures have been manufactured to characterize long-range dopant diffusion in tungsten silicide layers. A tungsten silicide to p-type silicon contact has been characterized as a Schottky barrier rectifying contact with a silicide work function of 4.8 eV. Long-range diffusion of boron for an anneal at 900 °C for 30 min has been shown to alter this contact to become ohmic. Long-range diffusion of phosphorus with a similar anneal alters the contact to become a bipolar n-p diode. Bipolar diode action is demonstrated experimentally for anneal schedules of 30 min at 900 °C, indicating long-range diffusion of phosphorus (~38 µm), SIMS analysis shows dopant redistribution is adversely affected by segregation to the silicide/oxide interface. The concept of conduit diffusion has been demonstrated experimentally for application in advanced bipolar transistor technology. © 2009 IEEE.

BUCKLED LAYER STRUCTURE FOR ATOMIC ADSORPTION ON W(100) - THE (ROOT-2X-ROOT-2)R45-DEGREES NITROGEN STRUCTURE FROM ATLEED

Adsorption of 0.5 monolayer of N adatoms on W{100} results in a sharp (root 2 X root 2)R45 degrees LEED pattern. The only previous quantitative LEED study of this system gave a simple overlayer model with a Pendry R-factor of 0.55. An exhaustive search has been made of possible structures, including a novel vacancy reconstruction, displacive reconstructions and underlayer adsorption. From this work a new overlayer structure is derived with an R(p) value of 0.22, displaying a considerable buckling of 0.27 +/- 0.05 Angstrom within the second W layer and consequently involving large changes in the interlayer spacings of the surface. The N adatom is pseudo-five-fold coordinated to the W surface, bonding to a second-layer W atom with a nearest-neighbour bond length of 2.13 Angstrom and with the four next-nearest-neighbour W atoms in the surface plane at 2.27 Angstrom. The structure does not resolve the work function anomaly observed on this surface.

Multiphysics Simulation of Nanostructured Semiconductor Devices

Thesis (Ph.D.)--University of Washington, 2013

Acompanhamento da III fase do aterro sanitário da Meia Serra

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização de Hidráulica

Structure et propriétés électroniques de nanotubes de carbone en solution polyélectrolyte

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

A review of the theoretical basis for bulk mass flux convective parameterization

Most parameterizations for precipitating convection in use today are bulk schemes, in which an ensemble of cumulus elements with different properties is modelled as a single, representative entraining-detraining plume. We review the underpinning mathematical model for such parameterizations, in particular by comparing it with spectral models in which elements are not combined into the representative plume. The chief merit of a bulk model is that the representative plume can be described by an equation set with the same structure as that which describes each element in a spectral model. The equivalence relies on an ansatz for detrained condensate introduced by Yanai et al. (1973) and on a simplified microphysics. There are also conceptual differences in the closure of bulk and spectral parameterizations. In particular, we show that the convective quasi-equilibrium closure of Arakawa and Schubert (1974) for spectral parameterizations cannot be carried over to a bulk parameterization in a straightforward way. Quasi-equilibrium of the cloud work function assumes a timescale separation between a slow forcing process and a rapid convective response. But, for the natural bulk analogue to the cloud-work function (the dilute CAPE), the relevant forcing is characterised by a different timescale, and so its quasi-equilibrium entails a different physical constraint. Closures of bulk parameterization that use the non-entraining parcel value of CAPE do not suffer from this timescale issue. However, the Yanai et al. (1973) ansatz must be invoked as a necessary ingredient of those closures.

Born-Oppenheimer failure in the separation of low frequency vibrations

Changes in the effective potential function of a low-frequency large-amplitude molecular vibration, resulting from excitation of a high-frequency vibration, are discussed. It is shown that in some situations a significant contribution to such changes may arise from failure of the Born-Oppenheimer separation of the low-frequency mode. In the particular example of the HF dimer, recent evidence that the tunneling barrier increases on exciting either of the H-stretching vibrations is probably due to this effect.

Spectroscopy of ultrathin epitaxial rutile TiO[sub 2](110) films grown on W(100)

Epitaxial ultrathin titanium dioxide films of 0.3 to similar to 7 nm thickness on a metal single crystal substrate have been investigated by high resolution vibrational and electron spectroscopies. The data complement previous morphological data provided by scanned probe microscopy and low energy electron diffraction to provide very complete characterization of this system. The thicker films display electronic structure consistent with a stoichiometric TiO2 phase. The thinner films appear nonstoichiometric due to band bending and charge transfer from the metal substrate, while work function measurements also show a marked thickness dependence. The vibrational spectroscopy shows three clear phonon bands at 368, 438, and 829 cm(-1) (at 273 K), which confirms a rutile structure. The phonon band intensity scales linearly with film thickness and shift slightly to lower frequencies with increasing temperature, in accord with results for single crystals. (c) 2007 American Institute of Physics.

Finite departure from convective quasi-equilibrium: periodic cycle and discharge-recharge mechanism

A simple self–contained theory is proposed for describing life cycles of convective systems as a discharge–recharge process. A closed description is derived for the dynamics of an ensemble of convective plumes based on an energy cycle. The system consists of prognostic equations for the cloud work function and the convective kinetic energy. The system can be closed by intro ducing a functional relationship between the convective kinetic energy and the cloud–base mass flux. The behaviour of this system is considered under a bulk simplification. Previous cloud–resolving mo delling as well as bulk statistical theories for ensemble convective systems suggest that a plausible relationship would be to assume that the convective kinetic energy is linearly proportional to the cloud–base mass flux. As a result, the system reduces to a nonlinear dynamical system with two dependent variables, the cloud–base mass flux and the cloud work function. The fully nonlinear solution of this system always represents a periodic cycle regardless of the initial condition under constant large–scale forcing. Importantly, the inclusion of energy dissipation in this model does not in itself lead the system to an equilibrium.

Generalized convective quasi-equilibrium principle

A generalization of Arakawa and Schubert's convective quasi-equilibrium principle is presented for a closure formulation of mass-flux convection parameterization. The original principle is based on the budget of the cloud work function. This principle is generalized by considering the budget for a vertical integral of an arbitrary convection-related quantity. The closure formulation includes Arakawa and Schubert's quasi-equilibrium, as well as both CAPE and moisture closures as special cases. The formulation also includes new possibilities for considering vertical integrals that are dependent on convective-scale variables, such as the moisture within convection. The generalized convective quasi-equilibrium is defined by a balance between large-scale forcing and convective response for a given vertically-integrated quantity. The latter takes the form of a convolution of a kernel matrix and a mass-flux spectrum, as in the original convective quasi-equilibrium. The kernel reduces to a scalar when either a bulk formulation is adopted, or only large-scale variables are considered within the vertical integral. Various physical implications of the generalized closure are discussed. These include the possibility that precipitation might be considered as a potentially-significant contribution to the large-scale forcing. Two dicta are proposed as guiding physical principles for the specifying a suitable vertically-integrated quantity.

Adequação do currículo do curso de pedagogia: habilitação em administração escolar e orientação educacional: ao mercado de trabalho

O objetivo deste trabalho foi o de estudar o currículo do Curso de Pedagogia (habilitação em Administração Escolar e Orientação Educacional) da Faculdade de Educação da Universidade do Amazonas. Procurou-se examinar também a relação existente entre a formação e as condições de desempenho de Administradores Escolares e Orientadores Educacionais atuando nas Escolas Estaduais de 1º e 2º graus, na cidade de Manaus, Estado do Amazonas. O trabalho consta de duas etapas: a primeira contém a importância do estudo, as hipóteses que fundamentaram o mesmo e a fundamentação teórica, onde nos detivemos principalmente nas figuras dos dois especialistas: o Adm.Esc. e o O.E., em seus aspectos teóricos e atribuições legais; a segunda constitue-se de uma Pesquisa de campo, onde foram utilizados três instrumentos, abrangendo as seguites áreas: avaliação dos cursos; metodologia; estágio supervisionado; avaliação do rendimento; realidade social e condições de atuação. A população estudada consta de 80 elementos exercendo as funções de Diretores, Administradores Escolares e Orientadores Educacionais. Os resultados obtidos evidenciaram um hiato entre a formação oferecida pela Faculdade de Educação da Universidade do Amazonas, e as condições de atuaçao dos profissionais em estudo. Os Adm. Esc. (em função de Assessor) estão exercendo funções para as quais não necessitam formação em nível superior; os O.E. não dispõem de condições para uma atuação efetiva, dentro do que é preconizado pelos teóricos da Orientação Educacional; os profissionais estudados apontam como principal ponto de estrangulamento em seu desempenho o distanciamento entre a teoria e a prática oferecidas nos cursos de graduação; notou-se que os O.E. mostraram-se mais críticos quanto à formação recebida, do que os Adm. Esc. Sugere-se no final do trabalho, pesquisas que visem aprofundar o conhecimento da realidade educacional pesquisada.

O educando com síndrome de down: um estudo sobre a relação entre pais e profissionais na escola regular

This work makes a documental analise about the relationship between families of Down syndrome students and professionals of who teach them, in order to improve the process of developing teaching-learning, in an inclusive perspective. For this, we use a qualitative approach, because we believe that the object of research is not a passive and neutral knowledge, since it has meanings and relationships whose can be better interpreted and understood by the researcher in a real and active situation. For the development of this research, a bibliographical review was made about the subject, and a case studied in two regular education schools, both of them at the city of Natal/RN, one public and another one particular. We work on these educational institutions with professionals and parents of Down syndrome students. As an instrument of building information we used a semi-structured interview and to analise the results a qualitative method. Crossing the stages, we noticed: the pedagogical coordinators who made up both analyzed schools showed interest about doing an effective work with parents, regardless of Educational Policy Project of each school, predict or not the participation on educational undertaken process; On teachers discourses, reporting the relationship with the family, we realize that one of those teachers try to keep a good relationship with parents, permeated by learning exchanges, guidance and knowledge, in relation to another one, even existing an apparent openness to dialogue, when parents have any suggestions or criticism, that attitude is not always well coming. From the parents interviews, we can emphasize, first of all, that both of them recognize the benefits of inclusion, with regard to socialization - in general from the coexistence with pairs and the process of teaching and learning, as shown in a consistent way. Regarding school meetings with teachers, the studied parents agree about importance of such appointments and try to attend them, besides the other events organized by the school, beyond keeping individual touch with the teacher, when necessary. They are always present, looking for get envolved in everything that happens at school, in order to know better what is being done, listening and may suggest alternatives to improving the educational process. We perceive, from the study undertaken, that although the school inclusion is not an easy process to be built, is something that could be achieved. For this, is necessary that professionals of education and families recognize their functions in the educational process and act jointly on this direction

Análise operacional e econômica do processamento de madeira de Eucalitpo com Hypro em região montanhosa

O processo constante de avaliação técnica e econômica dos sistemas de colheita de madeira é intrínseco às empresas florestais, devido ao fato de corresponder a uma fase de suma importância que despende elevado investimento financeiro. No experimento deste trabalho, estudaram-se o rendimento operacional e custos operacionais e de produção do processador florestal Hypro. A análise técnica englobou estudos de tempos e movimentos pelo método de tempo contínuo. O rendimento operacional foi determinado através do volume, em metros cúbicos de madeira processada. A análise econômica incorporou os parâmetros do custo operacional, custo de processamento da madeira e rendimento energético. A análise dos dados evidenciou que o rendimento operacional por hora efetiva de trabalho foi de 38 árvores e, em metros cúbicos sem casca por hora efetiva de trabalho, de 11,68 m³ h-1, com custo de processamento de madeira sem casca de US$ 6.85 por metro cúbico.

Influência do relevo na produtividade e custos do harvester

Among the several variables that influence timber harvesting is the slope, which influences the productivity of forest machines. In this experiment the harvester was evaluated technically and economically while cutting and processing eucalyptus activity on different slope classes. The technical analysis included a study of time and movements by the method of continuous time; productivity was determined by the volume in cubic meters of wood processing. The economic analysis included the parameters of operational cost, production cost and energy consumption. The analysis of the data showed that productivity decreased according to the increase of the percent slope inclination, resulting in an effective work hour productivity increase from 18.72 to 39.71 m(3)sc, with a mean of operating cost of US$ 78.78 per work hour.