Esta tese investigou como o uso do Sistema de Controle Gerencial influencia na gestão da resiliência organizacional de uma empresa brasileira. A escolha pelo modelo teórico \"Levers of Control\" de Robert Simons (1995, 2000) está vinculada ao seu objetivo que é analisar quais são os sistemas de controle gerencial utilizados pela organização para promover a renovação da estratégia organizacional, com isto auxiliar na gestão da resiliência estratégica da organização. Desenvolveu-se um survey single entity em uma empresa do setor de comércio de derivados de petróleo, com estrutura, porte e sistema de controle gerencial demandados para a investigação. A empresa escolhida foi conveniente pois, no momento da pesquisa, estava vivenciando um momento de tensão em relação a sua estrutura e modo de funcionamento. O levantamento dos dados ocorreu a partir de um questionário enviado aos executivos de diversas áreas da organização abrangendo uma amostra de 64 gestores organizacionais. Os resultados suportam a hipótese de que o uso do sistema de controle gerencial impacta positivamente na resiliência estratégica porque permite uma visão estruturada para ação e reação das organizações. Observou-se que elevados níveis do uso do sistema de controle gerencial nas formas de sistemas de crenças, restrições, uso diagnóstico e uso interativo aumentam a capacidade da organização para a resiliência ao atuarem de forma proativa, com visão estratégica frente às adversidades do cenário empresarial, proporcionando a renovação da estratégica proposta por Simons (1995). Dentre as contribuições da pesquisa, destacam-se: (i) a discussão sobre o sistema de controle gerencial sob o prisma das alavancas de controle gerencial de Simons (1995, 2000) no cenário nacional e sua associação com a teoria da resiliência organizacional; (ii) o desenvolvimento e a validação de uma ferramenta para mensurar resiliência estratégica no nível empresarial; e (iii) do ponto de vista prático, este estudo auxilia os gerentes a decidirem qual padrão de controle melhor se adequa às circunstâncias em que operam e aos seus desafios estratégicos, contribuindo para a compreensão de como o uso do sistema de controle gerencial impacta a resiliência no ambiente organizacional. / This Ph.D. dissertation investigated how the use of the Management Control System influences in the management of organizational resilience in a Brazilian company. The choice by the theoretical model named \"Levers of Control\" by Robert Simons (1995, 2000) is linked to its purpose to analyze which are the management control systems used by the organization to provide the strategic renewal and helping with the organization\'s strategic resilience management. A survey single entity developed in a Brazilian oil derivative trading company with structure, size and management control system required for the research. The chosen company was convenient because, at the time of the research, it was experiencing a moment of tension in relation to its structure and mode of operation. The data were collected based on a questionnaire sent to executives from different departments, covering a sample of 64 organizational managers. The results support the hypothesis that the use of the management control system has a positive impact on the strategic resilience because it allows a structured view for organizations\' action and reaction. Thus, it was observed that high levels of the use of the management control system in the forms of beliefs systems, boundary systems, diagnostic control system and interactive control system increase the organization\'s capacity for resilience by acting in a proactive way, with strategic vision facing the business context\'s adversities, providing the strategic renewal proposed by Simons (1995). Among the research contributions, the following stand out: (i) the theoretical discussion about the Management Control System through the prism of Levers of Control by Simons (1995, 2000) in the national scenario, and its association with the organizational resilience theory; (ii) the development and validation of a tool to measure strategic resilience at the organizational level; and (iii) the practical point of view, this research helps managers to decide which pattern of control best fits the circumstances in which they operate and their strategic challenges, contribute to understanding how the use of management control system impacts on the resilience in the organizational environment.

In this work, we use optical approaches to study and provide mechanistic insight into electrochemical reactions occurring at the surface of single nanoparticles. Correlated optical-electrochemical studies offer several advantages over single nanoparticle electrochemical studies including, higher spatial resolution, the ability to interrogate many nanoparticles at the same time and identify populations of inactive nanoparticles. Throughout this dissertation, two optical techniques are discussed in detail, dark-field scattering and super-localization imaging. In the first set of experiments, we describe calcite-assisted localization and kinetics (CLocK) microscopy, a multiparameter super-localization imaging technique. By placing a rotating birefringent calcite crystal in the infinity space of an optical microscope, CLocK provides immediate polarization and orientation information while still maintaining the ability to localize a single nanoparticle with < 10 nm resolution. Additionally, we demonstrate that the CLocK point spread function encodes kinetic information that we quantified to be an order of magnitude shorter than the integration time of the camera. In this work, CLocK provides new mechanistic insight into dynamic processes such as the dissolution of single gold nanorods as well as single-molecule surface-enhanced Raman scattering. In the second work, dark-field scattering was employed to monitor a proposed post-synthesis silver nanoparticle surface cleaning strategy to improve homogeneity across a population. Here, a sacrificial silver-sulfide sulfide shell is chemically grown on single silver nanoparticles to outcompete surface impurities. We demonstrate that upon electrochemical removal of the shell, a more reactive and reproducible silver surface can be achieved as revealed by enhanced electrodissoluion of the freshly cleaned silver nanoparticles. In these experiments, we additionally found a sulfide-dependent formation of multiple sulfide-species as well as mixed character sulfide shells on single nanoparticles themselves, thus demonstrating the sensitivity provided by optical microscopy at identifying multiple surface chemistries. Overall, the work in this dissertation highlights the ability of optical tools at revealing heterogeneity in single particle studies providing insight into structure-function relationships. / Physiology

In this work, we use optical methods to study electrochemical reactions and processes occurring on the nanometer length scale. Optical methods are advantageous over traditional electrochemical methods because of their high spatial resolution and sensitivity at both the single nanoparticle and single molecule level. This dissertation describes a series of studies in which super-localization and dark-field optical imaging is used to provide insight into spatial and temporal heterogeneity in nanoscale electrochemical systems with &lt;25 nm spatial resolution. In the first set of experiments, three-dimensional (3-D) super-resolution imaging is used to determine the tip-substrate distance in nanoscale scanning electrochemical microscopy (SECM) with precision better than 25 nm. Correlating the tip-substrate distance using both optical and electrochemical techniques showed excellent agreement. Second, single nanoparticles (NP) were delivered through a nanopipette, and their resistive-pulse signals were correlated with a fluorescence optical signal. The diffusion trajectories of individual NP delivered to the external solution and to an electrified interface were obtained by 3-D super-resolution imaging, and showed signatures of both sub-diffusive and super-diffusive behavior, depending on the balance of forces between the flow from the pipette and the applied potential at the electrified substrate. Next, we studied the influence of surface oxide layers on single silver NP electrodissolution by tracking the intensity and spatial variation of scattering from single nanoparticles over time. We discovered that silver NPs can undergo electrodissolution in either a spatially symmetric or asymmetric manner, based on the nature of the surface oxide layer. Moreover, we also reported the simultaneous electrodeposition of silver oxide at the electrode surface during the electrodissolution of silver NPs, which enabled us to study the effect of multiple simultaneous redox reactions and their effects on one another. Overall, these experiments reveal local heterogeneity in nanoscale electrochemical processes and allow for many single nanoparticles to be measured in parallel, revealing relationships that are hidden using traditional electrochemical measurements. / Chemistry

In this work, we use optical techniques to provide insight into how various components within electrochemical cells can impart apparent heterogeneity to single gold nanoparticle electrodes. Optical methods are advantageous in comparison to traditional electrochemical techniques due to their high sensitivity and spatial resolution, allowing us to study the impact of heterogeneity with single nanoparticle and single molecule sensitivity. Throughout the course of this dissertation, two optical techniques are discussed in detail, dark-field microscopy, and single molecule fluorescence imaging. We first began by studying the impact of the substrate using dark-field microscopy to monitor the electrodissolution kinetics of gold nanoparticles on thin films of tin-doped indium oxide (ITO), which is a commonly used supporting electrode for correlated optical and electrochemical studies. We found that ITO from two different suppliers showed marked differences in the gold electrodissolution kinetics, with ITO from one of the suppliers even showing poor sample-to-sample reproducibility across substrates within the same lot number. These results showed that the supporting electrode cannot be ignored when performing single nanoparticle structure-function studies. In the second work, we analyzed the electrodissolution of gold nanoparticles on well-behaved ITO substrates to investigate heterogeneity in their electrodissolution kinetics. The rate constants associated with the electrodissolution of Au NPs were extracted by fitting the intensity-time traces to a first-order kinetic model. We found that a non-negligible population of Au NPs didn’t fit the predictive kinetics model leading us to further probe whether surface effects play a role in the electrodissolution process. Super-localization imaging was used to track the center position of the Au NPs as they electrodissolved revealing three distinct electrodissolution behaviors, and a mechanism for the electrodissolution of Au NPs was proposed. Furthermore, calcite-assisted localization and kinetics (CLocK) microscopy was used to visualize changes in anisotropy and provide information as to how the shape of the Au NP changes as it electrodissolves. Lastly, in our third work, we provide insight as to how heterogeneity from all the different components of a single nanoparticle electrochemical sample impacts the apparent electrode performance. We proposed dark-field microscopy and single molecule fluorescence imaging as tools capable of detangling these effects. Moreover, we established Cresyl Violet as a reporter of single molecule electrochemistry and developed a two-working electrode optical system capable of visualizing single molecule activity. Lastly, we explored the relationships between Au NP size, Cresyl Violet activity and Au NP electrodissolution and found no clear trend between them suggesting the need for more studies to deconvolute these effects and provide meaningful insight into the structure-property relationships. Overall, this dissertation highlights the complexity of single nanoparticle studies and how heterogeneity can be induced from all the components of an electrochemical cell. / Chemistry