Wang Yang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 80-81). / Abstracts in English and Chinese. / Abstract --- p.i / 摘要 --- p.iii / Table of Contents --- p.iv / List of figures --- p.v / Introduction --- p.1 / Structuring analytical shape grammar --- p.1 / Shape grammar implementation --- p.5 / 3D ting tang generator --- p.7 / Chapter Chapter 1 --- Shape grammar: written grammar and implementations --- p.11 / Shape grammar --- p.11 / Written grammars --- p.12 / Analytical grammars --- p.13 / Shape grammar implementations --- p.14 / Chase's shape grammar system: user interaction mode and emergence --- p.15 / GEdit and Shaper 2D: graphic interface --- p.17 / Chapter Chapter 2 --- Understanding the task of creating ting tang --- p.20 / Model of work --- p.20 / Author of an shape grammar interpreter --- p.21 / What does this interpreter offer? --- p.22 / Before the interpreter: understanding ting tang and the ting tang grammar --- p.23 / The grammar by Li and the grammar for the generator --- p.24 / The process of creating a ting tang in the generator --- p.25 / Chapter Chapter 3 --- The interface and implementation --- p.30 / An illustrated example: --- p.30 / Stage one: --- p.32 / Stage two: --- p.50 / Stage three: install the 3-dimensional components --- p.58 / The two types of step: deterministic and nondeterministic steps --- p.65 / Stage one --- p.65 / Stage two --- p.70 / Stage three --- p.73 / The interface and user control --- p.73 / The back and forward buttons --- p.73 / The inquiry window --- p.74 / Chapter Chapter 4 --- Conclusion --- p.75 / Dynamic rules --- p.75 / Derivation and labels --- p.76 / The limited interface within AutoCAD --- p.77 / Fixed rules --- p.78 / References --- p.80

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-08-29T19:55:47Z No. of bitstreams: 1 2016 - F?bio Silva de Figueiredo.pdf: 2186120 bytes, checksum: 5f3d5936d788a69c7a74b4e99a15f229 (MD5) / Made available in DSpace on 2018-08-29T19:55:47Z (GMT). No. of bitstreams: 1 2016 - F?bio Silva de Figueiredo.pdf: 2186120 bytes, checksum: 5f3d5936d788a69c7a74b4e99a15f229 (MD5) Previous issue date: 2016-03-30 / Managing organizational knowledge is still something challenging to the current public organizations. Manage it in internal consulting projects can be even more laborious. The public organization in question is a Federal University of southeastern Brazil that in recent years has developed internal consulting projects with its planning sector. This business model was born of the need to respond more effectively to organizational shortcomings that originated, above all, by the rapid expansion that this organization has suffered in recent years due to the REUNI program. They are related, especially, about complex administrative demands such as purchasing large-scale, and studies of administrative restructuring that require further analysis to its correct solution which escapes from the daily operating of the internal departments. However, this model has brought with it, beyond the actual benefits of the internal consultation, a significant increase of organizational knowledge which is now routinely created by this team. Thus, it was realized a strategic gap in determining a tool that was able to systematize this organizational knowledge. Thus, based on the knowledge conversion model (SECI model - socialization, externalization, combination, internalization) of Nonaka and Takeuchi (1997) and assuming that the practice of lessons learned is crucial and critical for the systematization of organizational knowledge in internal consulting projects, came to the formulation of the following research question: how the practice of lessons learned could systematize the organizational knowledge in projects developed by an internal consulting team in a federal institution of higher education? To get the answer to that question, it sought to investigate how internal consulting projects and knowledge management can take advantage of the lessons learned practices for effective management of organizational knowledge within these projects. This is an applied research, its nature is descriptive, it has a qualitative approach and uses the single case study method. As a result it was identified that the application of the lessons learned in knowledge management process is intrinsically linked to the dynamics of the interaction between tacit and explicit knowledge that this practice can provide, leading to the creation of organizational knowledge and also that it is an important organizational process asset that can avoid mistakes in future projects and promote the perpetuation of best practices in this team. Therefore, the conclusion is that the lessons learned systematize knowledge management in internal consulting teams at the moment this is a tool that create a dynamic of interactions among the team that permeates the whole spiral of knowledge creation in a upward and continuous movement. Finally, it is expected that this work adds value to the field of knowledge management in projects, notably in the public sector and will help to stimulate future studies on these subjects. / Gerenciar o conhecimento organizacional ainda ? algo desafiador para as organiza??es p?blicas atuais. Gerenci?-lo em projetos de consultoria interna pode ser ainda mais trabalhoso. A organiza??o p?blica em quest?o ? uma Universidade Federal do sudeste do Brasil que nos ?ltimos anos vem desenvolvendo projetos de consultoria interna junto ao seu setor de planejamento. Este modelo de gest?o nasceu da necessidade de se responder de maneira mais efetiva ?s car?ncias organizacionais que se originaram, acima de tudo, da r?pida amplia??o que esta organiza??o sofreu nos ?ltimos anos em virtude do programa REUNI. Esses projetos versam, sobretudo, acerca de demandas administrativas complexas, como compras de grande vulto e estudos de reestrutura??o administrativa que demandam uma an?lise mais aprofundada para a sua correta solu??o o que, em princ?pio, foge do cotidiano operacional dos ?rg?os internos. Entretanto, esse modelo trouxe consigo, al?m dos benef?cios pr?prios da consultoria interna, um expressivo aumento do conhecimento organizacional que passou a ser rotineiramente criado por essa equipe. Assim, percebeu-se uma lacuna estrat?gica na determina??o de uma ferramenta que fosse capaz de sistematizar este conhecimento organizacional. Desse modo, tendo como base o modelo de convers?o do conhecimento (modelo SECI ? Socializa??o, externaliza??o, combina??o, internaliza??o) de Nonaka e Takeuchi (1997) e partindo do pressuposto de que a pr?tica de li??es aprendidas ? determinante e cr?tica para a sistematiza??o do conhecimento organizacional em projetos de consultoria interna, chegou-se ? formula??o da seguinte pergunta de pesquisa: como a pr?tica de li??es aprendidas poderia sistematizar o conhecimento organizacional em projetos desenvolvidos por uma equipe de consultoria interna em uma institui??o federal de ensino superior? Para se obter a resposta a tal pergunta, buscou-se investigar como os projetos de consultoria interna e a gest?o do conhecimento podem se valer das pr?ticas de li??es aprendidas para efetiva gest?o do conhecimento organizacional no ?mbito desses projetos. A pesquisa ? aplicada, tem natureza descritiva, possui uma abordagem qualitativa e utiliza o m?todo de estudo de caso ?nico. Como resultado foi identificado que a aplica??o das li??es aprendidas ao processo de sistematiza??o do conhecimento est? intrinsecamente ligada ? din?mica da intera??o entre o conhecimento t?cito e expl?cito que esta pr?tica pode proporcionar, levando ? cria??o de conhecimento organizacional e tamb?m que ela ? um importante ativo de processo organizacional que pode, al?m de evitar erros em projetos futuros, promover a perpetua??o de melhores pr?ticas no contexto dessa equipe. Portanto, a conclus?o do estudo ? que as li??es aprendidas sistematizam a gest?o do conhecimento em equipes de consultoria interna no momento em que esta ? uma ferramenta capaz de criar uma din?mica de intera??es entre os indiv?duos que perpassa toda a espiral de cria??o do conhecimento em um movimento ascendente e cont?nuo. Por fim, espera-se, que este trabalho agregue valor ao campo da gest?o do conhecimento em projetos, notadamente no setor p?blico e contribua para estimular estudos futuros sobre estes temas.

Battery technology is a great candidate for energy storage applications. The need for high-performance and cost-effective batteries has motivated researchers to put much effort into improving battery performance. In this work, we attempt to understand the elements that affect the microstructure and performance of two battery systems. The first part of this work focuses on the investigation of transport and structural properties of porous electrodes in an alkaline electrolyte. A DC polarization method was deployed for tortuosity measurements. An apparatus was designed to flow specified current through and measure the voltage drop over the porous electrodes. Using a modified Ohm's law, effective diffusion coefficient and associated tortuosity were determined. Multiple compositions (different types and amounts of conductive additives) were tested to understand the effects of composition on the transport properties. As a validation and to further understand the tests, a model was developed and used for data analysis. The second part of this dissertation describes simulations of the manufacturing process of a Li-ion electrode. LAMMPS, a particle simulator, was used for this meso-scale particle-based simulation. The interactions between particles were understood by model-experiment comparisons of the macroscopic properties such as viscosity of the slurry and elasticity of the dried film. The microstructure created by this simulation was consistent with the one we observed in SEM/ FIB images. Although the emphasis was the drying process in this part, some preliminary coating and calendering simulations are presented. Finally, the effects of electrode heterogeneity were investigated by a Newman-type model and tomographic images. An electronic conductivity map was initially generated over a Li-ion cathode. Then SEM/FIB images of specified high, middle, and low conductivity regions were taken to confirm heterogeneity. For modeling purposes, three regions of high, middle, and low ionic resistance were considered connected in parallel, representing the real electrode heterogeneity. Multiple cases of heterogeneities such as non-uniform ionic resistance and active material loading at low, middle, and high charge-discharge rates were studied. The results show that higher rates increase non-uniformities of dependent properties such as temperature, current density, positive and negative electrodes states of charge, and charge and discharge capacities especially in charging cases.

Layered lithium transition-metal oxides (LMOs) are used as the positive electrode material in rechargeable lithium-ion batteries. Because transition metals undergo redox reactions when lithium ions intercalate in and disintercalate from the lattice, the selection and composition of transition metals largely influence the electrochemical performance of LMOs. Recently, a Ni-rich compound, LiNi0.8Co0.1Mn0.1O2 (NCM811), has drawn much attention. It is expected to replace its state-of-the-art cousins, LiCoO2 (LCO) and LiNi1/3Co1/3Mn1/3O2 (NCM111), because of its higher capacity, lower cost, and reduced toxicity. However, the excess Ni, as a transition-metal element in NCM811, can cause structural and cycling instability. Starting from NCM811, I modified the composition of transition metals by two approaches: 1) introducing cobalt deficiency and 2) substituting Ni, Co, and Mn with Zr. Their influences on the phase, structure, cycling performance, rate capability, and ionic transport were investigated by a variety of characterization techniques. I found that cobalt non-stoichiometry can suppress Ni2+/Li+ cation mixing, but simultaneously promotes the formation of oxygen vacancies, leading to rapid capacity fade and inferior rate capability compared to pristine NCM811. On the other hand, Zr can reside on and expand the lattice of NCM811, and form Li-rich lithium zirconates on their surfaces. In particular, 1% Zr substitution can increase the stability of NCM811 and facilitate Li-ion transport, resulting in enhanced cycling durability and high-rate performance. My studies help improve the understanding of the effects of transition metals on the degradation of the Ni-rich layered positive electrode material and provide modification strategies to enhance its performance and durability for Li-ion battery applications.

Ce travail concerne la recherche et le développement de nouveaux matériaux à base d'étain, pour une application comme électrode négative des batteries rechargeables lithium ion. Afin de comprendre la relation Structure-texture-propriétés permettant d'optimiser le matériau, un ensemble de techniques de caractérisation complémentaires (Diffraction des rayons X, Microscopie électronique à balayage, analyse thermiques et gravimétriques ATD-ATG, spectroscopie Mössbauer de 119Sn et absorption X) ont été associées pour caractériser l'ordre global et l'ordre local dans le matériau. Une analyse détaillée du mécanisme de fonctionnement du matériau composite [Sn-BPO4], réalisée en couplant des méthodes électrochimiques et spectroscopiques, a permis de comprendre la réversibilité du système et de mettre en évidence les intermédiaires réactionnels grâce notamment à la spectroscopie Mössbauer in situ de 119Sn. Le matériau composite testé dans des cellules de laboratoire, montre des caractéristiques électrochimiques intéressantes, une capacité massique de 500 mAh/g et une bonne tenue en cyclage. Ces performances sont liées fortement à la meilleure dispersion de l'élément électroactif et à un solide accrochage à la surface de la matrice grâce à une interface amorphe formée entre les deux composants. Le matériau optimisé a été testé dans des conditions industrielle proposées par la société SAFT-Bordeaux, dans le but d'étudier l'effet de la technologie d'électrode sur les performances électrochimiques

L'objectif de cette étude est de progresser dans la compréhension des évolutions microstrucutrales de deux alliages Al-Li-Cu de la série 2000 lors du revenu et de faire le lien entre les microstructures obtenues et les propriétés mécaniques résultantes. En s'appuyant sur des techniques de caractérisation telles que la diffusion centrale des rayons X et la microscopie électronique en transmission nous avons pu identifier les séquences de précipitation lors du revenu et mesurer les cinétiques de crois- sance des principales phases en présence dans les deux alliages, à savoir T1 (Al2CuLi) et δ' (Al3Li) ainsi que de caractériser leurs séquences de précipitation en fonction des conditions antérieures au revenu. Un modèle de cinétique de croissance de la phase T1 au cours du revenu est proposé. En parallèle, l'étude des évolutions de limite d'élasticité, de comportement plastique et de réversibilité du glissement lors du revenu ont permis de comprendre l'influence de la précipitation sur les évolutions des propriétés mécaniques, à l'aide d'un modèle décrivant l'écrouissage comme l'addition d'une composante isotrope et d'une compo- sante cinématique. Enfin, l'étude de la ténacité dans le sens travers court et de l'évo- lution des modes de rupture de l'alliage par des essais de déchirement ont mis en évidence une forte influence du temps de revenu sur l'évolution de la précipitation intergranulaire.

<p>Understanding lithium-ion insertion/extraction mechanisms in battery electrode materials is of crucial importance in developing new materials with better cycling performance. In this thesis, these mechanisms are probed for two different potential cathode materials by a combination of electrochemical and single-crystal X-ray diffraction studies. The materials investigated are V₆O₁₃and cubic LiMn₂O₄spinel.</p><p>Single-crystal X-ray diffraction studies of lithiated phases in the Li_xV₆O₁₃ system (x=2/3 and 1) exhibit superlattice phenomena and an underlying Li⁺ ion insertion mechanism which involves the stepwise addition of Li⁺ions into a two-dimensional array of chemically equivalent sites. Each successive stage in the insertion process is accompanied by a rearrangement of the Li⁺ ions together with an electron redistribution associated with the reduction of specific V-atoms in the structure. This results in the formation of electrochemically active sheets in the structure. A similar mechanism occurs in the LiMn₂O₄ delithiation process, whereby lithium is extracted in a layered arrangement, with the Mn atoms forming charge-ordered Mn³⁺/Mn⁴⁺ layers.</p><p>Lithium-ion insertion/extraction processes in transition-metal oxides would thus seem to occur through an ordered two-dimensional arrangement of lithium ions extending throughout the structure. The lithium ions and the host structure rearrange cooperatively to form superlattices through lithium and transition-metal ion charge-ordering. A picture begins to emerge of a universal two-dimensional lithium-ion insertion/extraction mechanism analogous to the familiar staging sequence in graphite.</p>

<p>Reliable ways of storing energy are crucial to support our modern way of life; lithium-ion batteries provide an attractive solution. The constant demand for higher energy density, thinner, lighter and even more mechanically flexible batteries has motivated research into new battery materials. Some of these will be explored in this thesis.</p><p>The main focus is placed on the development of new anode materials for lithium-ion batteries and the assessment of their electrochemical and structural characteristics. The materials investigated are: natural Swedish graphite, SnB₂O₄ glass and intermetallics such as: Cu₆Sn₅, InSb, Cu₂Sb, MnSb and Mn₂Sb. Their performances are investigated by a combination of electrochemical, <i>in si</i>tu X-ray diffraction and Mössbauer spectroscopy techniques, with an emphasis on the structural transformations that occur during lithiation.</p><p>The intermetallic materials exhibit a lithium insertion/metal extrusion mechanism. The reversibility of these reactions is facilitated by the strong structural relationships between the parent compounds and their lithiated counterparts. Lithiation of a majority of the intermetallics in this work proceeds via an intermediate ternary phase. The intermetallic electrodes provide high volumetric capacities and operate at slightly higher voltages vs. Li/Li⁺ than graphite. This latter feature forms the basis for a safer system.</p><p>Jet-milling of natural Swedish graphite results in decreased particle and crystallite size, leading to improved performance; the capacity is close to the theoretical capacity of graphite. Jet-milled graphite also shows an enhanced ability to withstand high charging rates.</p>

<p>Nanomaterials have attracted great interest in recent years, and are now also being considered for battery applications. Reducing the particle size of some electrode materials can increase battery performance considerably, especially with regard to capacity, power and rate capability. This thesis presents a study focused on the performance of such a material, vanadium oxide nanotubes, as cathode material for rechargeable lithium batteries.</p><p>These nanotubes were synthesized by a sol-gel process followed by hydrothermal treatment. They consist of vanadium oxide layers separated by structure-directing agents, normally amines or metal ions, e.g., Na⁺, Ca²⁺, Mn²⁺ and Cu²⁺. The layers are arranged in a scroll-like manner, allowing the interlayer structure to expand and contract, depending on the size of the embedded guest. This tubular form of vanadium oxide was able to insert lithium ions reversibly, making it a candidate cathode material. The structural and electrochemical response to lithium ion insertion was carefully studied to define optimal performance criteria and probe the lithium insertion mechanism. This was done using several characterization techniques, including X-ray diffraction, a variety of spectroscopic methods and electrochemical testing. Galvanostatic measurements show that the material can be charged and discharged reversibly for >100 cycles with a capacity of 150-200 mAh/g. The electrochemical performance is, however, dependent on the electrode film preparation technique, the choice of salt in the electrolyte and the nature of the embedded guest. Results from photoelectron spectroscopy, and soft X-ray emission and absorption spectroscopy confirm that vanadium is reduced during lithium insertion and that three oxidation states (V⁵⁺, V⁴⁺and V³⁺) co-exist at potentials below 2.0 V. <i>In situ</i> X-ray diffraction, performed during potential stepping, identifies two separate processes during lithium insertion: a fast decrease of the interlayer distance followed by a slow two-dimensional relaxation of the vanadium oxide layers. </p>

<p>Li-ion batteries are not only a technology for the future, they are indeed already the technology of choice for today’s mobile phones, laptops and cordless power tools. Their ability to provide high energy densities inexpensively and in a way which conforms to modern environmental standards is constantly opening up new markets for these batteries. To be able to maintain this trend, it is imperative that all issues which relate safety to performance be studied in the greatest detail. The surface chemistry of the electrode-electrolyte interfaces is intrinsically crucial to Li-ion battery performance and safety. Unfortunately, the reactions occurring at these interfaces are still poorly understood. The aim of this thesis is therefore to increase our understanding of the surface chemistries and stability phenomena at the electrode-electrolyte interfaces for three novel Li-ion battery electrode materials.</p><p>Photoelectron spectroscopy has been used to study the surface chemistry of the anode material AlSb and the cathode materials LiFePO₄ and Li₂FeSiO₄. The cathode materials were both carbon-coated to improve inter-particle contact. The surface chemistry of these electrodes has been investigated in relation to their electrochemical performance and X-ray diffraction obtained structural results. Surface film formation and degradation reactions are also discussed.</p><p>For AlSb, it has been shown that most of the surface layer deposition occurs between 0.50 and 0.01 V <i>vs.</i> Li°/Li⁺ and that cycling performance improves when the lower cut-off potential of 0.50 V is used instead of 0.01 V. For both LiFePO₄ and Li₂FeSiO₄, the surface layer has been found to be very thin and does not provide complete surface coverage. Li₂CO₃ was also found on the surface of Li₂FeSiO₄ on exposure to air; this was found to disappear from the surface in a PC-based electrolyte. These results combine to give the promise of good long-term cycling with increased performance and safety for all three electrode materials studied.</p>