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den, Adel Menno, and Tobias Müller. "Re-Internationalisation : Exploring Opportunities in Turbulent Environments." Thesis, Linnéuniversitetet, Institutionen för marknadsföring (MF), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-65910.
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Our thesis is based on the constantly changing internal and external environment causing firms to increase or decrease their internationalisation efforts. The focus of this thesis is going to be on describing the process of re-internationalisation, including the different stages of de-internationalisation, time-out, and re-entry as well as identifying the influences of the internal and external environment on the process of re-internationalisation. The influences of the internal and external environmental on the process of re-internationalisation are analysed and accompanied by secondary data about the German biogas market, which the case company is considering to re-entry. The aim of the thesis is to contribute to existing literature by exploring the process of re-internationalisation and its stages of de-internationalisation, time-out and re-entry, to enhance the understanding of SME internationalisation patterns, and the influence of the internal and external environment The process of de-internationalisation for the case company was characterised by a lower degree of market commitment in contrast to a complete exit. The degree of commitment was maintained during time-out stage, but due to changes in the internal and external environment a move towards re-entering the market was considered. The main influences, found in this single case study, can be separated along the stages of de-internationalisation, time-out and re-entry. The de-internationalisation was mainly driven by poor economic results and a lack of resources. During the time-out, the company’s acquisition led to a change in firm objectives. The re-entry was mainly influenced by changes in institutional policies and the previously altered company objectives caused a consequential increase in resources. The change in institutional policies was perceived as a business opportunity. However, the analysis of the case company’s market showed a deviation between perceived and actual business opportunity, highlighting the importance of acquiring up-to-date market knowledge.
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Barrows, Edward. "How Firms in Turbulent Environments Measure Strategic Performance." Thesis, Cranfield University, 2014. http://dspace.lib.cranfield.ac.uk/handle/1826/9268.
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This thesis presents the findings from two case study examinations of strategic performance measurement systems within two turbulent environmental contexts: the U.S. security software industry and the U.S. health care industry.
Despite a three-‐decade emphasis on performance measurement research, little empirical work has been carried out inside turbulent settings—contexts characterized by rapid change, high levels of instability and complex configurations among environmental variables. This research targets that gap. Through exploratory case studies from seven security software firms paired with a single in-‐ depth case investigation within a transforming health care system, this study addresses the question: “how do firms in turbulent environments measure strategic performance?” The research found that in turbulent environments, an effective strategic performance measurement system contains six interrelated elements: management aims, performance objectives, uncertainty areas, decision data, management attention and performance measures. Top managers focus on their aims and performance objectives to meet requirements via a closed-‐loop approach while monitoring uncertainty areas and gathering decision data in an open-‐loop way. This union of feedback and feedforward control enables dynamic interaction among the various elements of the system all of which are informed by performance measure data. Effective use is moderated by management’s focus of attention.
The research has implications for information processing and management control literature; it extends existing theory to incorporate the use of semi-‐structures within the framework of the strategic performance measurement system as a means of overcoming the challenges of uncertainty. Further, the research contradicts both extant literature and practice convention that claims strategic performance measurement frameworks need to be balanced to be effective. Practitioners are provided with a strategic performance measurement framework for use in turbulent environments. The framework would benefit from further examination in a variety of different, equally turbulent, contexts.
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Lindgren, Mats. "Strategic flexibility : antecedents and performance implications in turbulent business environments." Thesis, Henley Business School, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341548.
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何學強 and Hok-keung Paul Ho. "Strategic issue management of real estate development in turbulent environments." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B43895037.
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Ho, Hok-keung Paul. "Strategic issue management of real estate development in turbulent environments." Hong Kong : University of Hong Kong, 2001. http://sunzi.lib.hku.hk/hkuto/record.jsp?B2521178x.
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Shrinivas, Ajay. "Unconfined and confined turbulent plumes and jets in stratified environments." Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/34507.
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The turbulent motions of buoyant plumes and momentum jets are ubiquitous in both the natural and built environments where a stable density stratification typically persists. The fluid mechanics of turbulent plumes and jets in stratified environments encompasses a fascinating and exigent field of research motivated by an extensive range of practical applications that include low-energy building ventilation, urban air quality management and the dispersion of pollutants in natural water bodies and the atmosphere. Merely as a consequence of vertical variations in the density of the ambient fluid, variations which often occur rapidly with depth in a shallow transitional layer (e.g. oceanic thermoclines and atmospheric inversions) separating two fluid masses, the fundamental behaviour of plumes and jets (in otherwise uniform environments) can be profoundly modified. This thesis investigates theoretically two intrinsic facets of turbulent plumes and jets in stratified environments. First, we examine the classic transport phenomenon of turbulent entrainment across a density interface driven by the localised impingement of a vertically-forced high-Reynolds-number jet. By developing theoretical models, we capture and elucidate the dominant physics at the heart of this complex physical process. Notably, the predictions of these models are in close agreement with existing experimental measurements. By unravelling the effects of confinement imposed by the physical boundaries of a box on the dynamics of interfacial entrainment, we highlight underlying physical reasons for the controversy surrounding the law governing the rate of entrainment across an interface. Second, we examine the time-dependent density stratification that develops in a confined environment following the activation of two turbulent plumes of unequal strengths. We show that the buoyancy of a bounded fluid layer can exceed, or overshoot, its steady value and that the plumes can induce a bulk overturning of the buoyant region. Finally, we discuss the wider context of this research and its application in engineering, the atmospheric sciences and oceanography.
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Coral, Nelson Fernando Ruiz. "The regulation of a corporation in turbulent environments : a systematic approach." Thesis, Lancaster University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304577.
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Angle, Chandrawatee W. "Stability of heavy oil emulsions in turbulent flow and different chemical environments." Thesis, University of Manchester, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.547848.
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Barnett, Lynn Elizabeth. "From anthropology to child psychotherapy : cross cultural observations of infants and turbulent environments." Thesis, University of East London, 2009. http://roar.uel.ac.uk/3888/.
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The central issue of the thesis is the innovative development of the Bick infant observation method into detailed, long term, cross-cultural video recording. Videos have been made which record individual infant development in UK, Western India, Nepal and Finland. Other observational videos demonstrate how the application of recent developmental theory can improve the care of infants in children's institutions. These are being used for teaching in over fourty countries but it is suggested that more detailed filmed records from these counties, and others, are needed. It is argued that video is invaluable for teaching and conference presentation as it substitutes seeing an actual situation for merely listening to or reading an individual verbal record. Further reasons for using the medium of video are fully discussed. There is a review of previous cross-cultural child development research recognising that it has been lacking in the area of infancy and that regrettably, it is not always included in the teaching of developmental theory. A major issue researched is the effects on children of turbulent environments: an environmental catastrophe (The Chernobyl disaster), the threat of nuclear war, an actual war (in Former Yugoslavia), the breakdown of a political system (in Russia), Day Nurseries and an Orphanage. The importance of human touch - a much neglected developmental issue in the West - is examined and visually recorded in a cross-cultural context as are beliefs about the nature of children. The papers, books and videos are all informed by attachment theory, psychoanalysis, systems theory and anthropology.
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Grib, Stephen William. "LAMINAR AND TURBULENT STUDY OF COMBUSTION IN STRATIFIED ENVIRONMENTS USING LASER BASED MEASUREMENTS." UKnowledge, 2018. https://uknowledge.uky.edu/me_etds/117.
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Practical gas turbine engine combustors create extremely non-uniform flowfields, which are highly stratified making it imperative that similar environments are well understood. Laser diagnostics were utilized in a variety of stratified environments, which led to temperature or chemical composition gradients, to better understand autoignition, extinction, and flame stability behavior. This work ranged from laminar and steady flames to turbulent flame studies in which time resolved measurements were used.
Edge flames, formed in the presence of species stratification, were studied by first developing a simple measurement technique which is capable of estimating an important quantity for edge flames, the advective heat flux, using only velocity measurements. Both hydroxyl planar laser induced fluorescence (OH PLIF) and particle image velocimetry (PIV) were used along with numerical simulations in the development of this technique. Interacting triple flames were also created in a laboratory scale burner producing a laminar and steady flowfield with symmetric equivalence ratio gradients. Studies were conducted in order to characterize and model the propagation speed as a function of the flame base curvature and separation distance between the neighboring flames. OH PLIF, PIV and Rayleigh scattering measurements were used in order to characterize the propagation speed. A model was developed which is capable of accurately representing the propagation speed for three different fuels. Negative edge flames were first studied by developing a one-dimensional model capable of reproducing the energy equation along the stoichiometric line, which was dependent on different boundary conditions. Unsteady and laminar negative edge flames were also simulated with periodic boundary conditions in order to assess the difference between the steady and unsteady cases. The diffusive heat loss was unbalanced with the chemical heat release and advective heat flux energy gain terms which led to the flame proceeding and receding. The temporal derivative balanced the energy equation, but also aided in the understanding of negative edge flame speeds. Turbulent negative edge flame velocities were measured for extinguishing flames in a separate experiment as a function of the bulk advective heat flux through the edge and turbulence level. A burner was designed and built for this study which created statistically stationary negative edge flames. The edge velocity was dependent on both the bulk advective heat flux and turbulence levels. The negative edge flame velocities were obtained with high speed stereo-view chemiluminescence and two dimensional PIV measurements.
Autoignition stabilization was studied in the presence of both temperature and species stratification, using a simple laminar flowfield. OH and CH2O PLIF measurements showed autoignition characteristics ahead of the flame base. Numerical chemical and flow simulations also revealed lower temperature chemistry characteristics ahead of the flame base leading to the conclusion of lower temperature chemistry dominating the stabilization behavior. An energy budget analysis was conducted which described the stabilization behavior.
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Adomako, Samuel, and P. N. Nguyen. "Interfirm Collaboration and CSR Expenditure in Turbulent Environments: The Moderating Role of Entrepreneurial Orientation." Wiley, 2020. http://hdl.handle.net/10454/17852.
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YesThis paper draws on resource dependency theory to examine the impact of interfirm collaboration on CSR expenditure. In addition, we examine entrepreneurial orientation (EO) as a moderator of the relationship between interfirm collaboration and CSR expenditure. We test our research model using survey data from 230 small and medium-sized enterprises (SMEs) in Ghana. Results from our empirical analyses reveal that interfirm collaboration positively impacts CSR expenditure and this relationship is strengthened when entrepreneurial orientation is greater in turbulent environments. Implications for theory and practice are discussed.
University of Economics Ho Chi Minh City, Vietnam
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Warille, J. B. "Sustainable compensation methods for construction companies operating in turbulent environments : a case of South Sudan." Thesis, University of Liverpool, 2016. http://livrepository.liverpool.ac.uk/3001198/.
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Although South Sudanese did not own private companies before the war, a good number of them have been studying business during the time of the war. Immediately after the signing of the Comprehensive Peace Agreement (CPA), private companies came into existence. Roads construction companies were not exceptions. Being new in the industry, the national companies have been copying from Sudan. The Labor Act (1997) of Sudan is the main employment legislation used in South Sudan. This thesis examines the compensation methods in three companies with the aim of suggesting methods that will suit turbulent environments like South Sudan. Three different methods were tested in intervals of three months to test its sustainability in environments like South Sudan. This is an action research project. Three workshops were held every three months and an evaluation of the compensation methods were made. Structured questionnaires were used to gain the understanding of employees about the compensation method in their respective organizations, their understanding of compensation in the environment in their operation areas, relationship of their pay to what their colleagues get and their attitude towards change in pay methods should the organization opt to do so. Interviews were also conducted with senior managers and board members to get their in-depth understanding of the compensation method in the companies they manage and in particular to look at how they sustain the pay. A close look at the Labor Act (1997) of Sudan which is being used in South Sudan was done to see the relevance of some of the acts in the South Sudan context. Though some areas of weaknesses in the pay systems were identified including the areas in some cultural behaviors which hinder concentration to work, the thesis came up with three different pay methods which can be used in South Sudan. They are Team Based Pay (TBP) with another form of Specialized Team Based Pay (STBP), Shared Pay Rate (SPR) and Management Driven Pay (MDP).
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van, Duijn Leonard Franklin. "Clausewitz inspired reflections on aid operations in turbulent environments : the case of Nepal 1999-2005/06." Thesis, Oxford Brookes University, 2009. https://radar.brookes.ac.uk/radar/items/6742805c-a71a-4039-b954-8be76b864fbf/1.
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This research is an exploratory single case study, which focuses on the interplay between aspects of Clausewitz's theory on war and the practice of aid agencies in Nepal between 1999-2005/06. During which period Nepal was embroiled in an escalating violent contlict between Maoist rebels and the ruling establishment. which had a severe impact on the operations of aid agencies present in Nepal. The study draws primarily on Clausewitz's theory on war to provide analytical tools of help to the aid industry and those in strategizing roles at country level in thinking through the challenges faced in unstable and deteriorating operational contexts, in order to further poverty and contlict reduction efforts. The research reflects on the processes of strategizing and implementing aid operations in turbulent environments from a Clausewitz-inspired perspective and advances two main findings. First, the thesis finds that one key concept used in this retlection process, which shows itself to be of practical help, is the 'aid trinity'. The 'aid trinity' is a normative reflective framework that consists of three interacting layers, being psychological, social and managerial, which facilitates the thinking through and strategizing of aid operations. Second, by borrowing Clausewitz notion of friction, the research demonstrates that the existence of multiple forms of friction present in processes of strategizing and implementing aid operations in turbulent contexts like Nepal, could severely hamper these operations. Friction can be understood as the mediating force between what was perceived as the ideal fonn of conducting aid operations in Nepal and their actual character, resulting in the inability of the international aid community to address appropriately the dynamics of poverty and conflict. The research highlights the need to factor in the reality of these multiple forms of friction and to allow for their impact in policy, strategizing and implementation processes, in the hope of maximizing poverty and contlict reduction efforts in fragile states and other turbulent environments.
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Al-Hussyni, Saad Kohel Ali. "Numerical study of turbulent plane jets in still and flowing environments employing two-equation k-ε model." Thesis, University of Edinburgh, 1987. http://hdl.handle.net/1842/11065.
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Hejazi, Kourosh. "Three-dimensional numerical and physical modelling of coastal hydro-environments : turbulent stratified flows in estuarine harbours and barrages." Thesis, Cardiff University, 2017. http://orca.cf.ac.uk/104358/.
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An arbitrary Lagrangian-Eulerian (ALE) three-dimensional hydrodynamic free-surface numerical model has been developed based on the time-dependent Reynolds-averaged Navier-Stokes (RANS) equations and the finite volume method (FVM). The model with non-hydrostatic pressure distribution and a structured nonorthogonal curvilinear staggered mesh is capable of simulating non-homogeneous stratified flows and problems involving complex bathymetry. A projection method is deployed for solving the set of the equations, and a buoyant k-ε turbulence model is included in the numerical model. Six new advection schemes are introduced, and a fifth-order-accurate upstream scheme was utilised in the numerical model. Extensive numerical tests showed the capability of the model in simulating free surface flows and non-linear terms in Navier-Stokes equations. To achieve a better understanding of hydrodynamics, mixing, and salt transport and stratification and their interactive mechanisms in estuarine harbours and barrages, a laboratory tidal basin was designed, set up and employed for velocity, water surface elevation and salinity measurements of an idealised vertically distorted model harbour. For despiking and denoising the velocity data a linear algorithm was established, which successfully lowered the noise level and removed the spikes. The measurements showed a horizontal circulation in the harbour and weak vertical circulations. The salinity suppressed the circulation across the water depth, resulting in less mixing in vertical direction and stronger flushing on the surface. Comparisons of the numerical model simulations against the experimental data showed that the velocities and flow patterns were in generally good agreement with the measured values. For the fresh water the model under-predicted the dominant velocity components for the areas with strong circulation and for the saline water the simulated results showed an overprediction in lower layers and good agreements with the measured values for the top layer. The water elevations exhibited very close predictions compared with the measured data. The salinity simulated profiles showed good agreements with the measured values for lower layers and an over-prediction for the top layer. The investigations showed that the dominant velocities inside the harbour were increased for taller barriers, but with the increase of mean water depth the circulations weakened. The saline water flushing into the harbour flows underneath the fresh ambient water resulting in higher salinity concentration in the harbour over time.
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Mohammed, Nor Azmi. "The Effect of Turbulent Flow on Corrosion of Mild Steel in High Partial CO2 Environments." Ohio University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1363706400.
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Ali, Shaukat. "Direct quadrature conditional moment closure for turbulent non-premixed combustion." Thesis, Queen Mary, University of London, 2014. http://qmro.qmul.ac.uk/xmlui/handle/123456789/7868.
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The accurate description of the turbulence chemistry interactions that can determine chemical conversion rates and flame stability in turbulent combustion modelling is a challenging research area. This thesis presents the development and implementation of a model for the treatment of fluctuations around the conditional mean (i.e., the auto-ignition and extinction phenomenon) of realistic turbulence-chemistry interactions in computational fluid dynamics (CFD) software. The wider objective is to apply the model to advanced combustion modelling and extend the present analysis to larger hydrocarbon fuels and particularly focus on the ability of the model to capture the effects of particulate formation such as soot. A comprehensive approach for modelling of turbulent combustion is developed in this work. A direct quadrature conditional moment closure (DQCMC) method for the treatment of realistic turbulence-chemistry interactions in computational fluid dynamics (CFD) software is described. The method which is based on the direct quadrature method of moments (DQMOM) coupled with the Conditional Moment Closure (CMC) equations is in simplified form and easily implementable in existing CMC formulation for CFD code. The observed fluctuations of scalar dissipation around the conditional mean values are captured by the treatment of a set of mixing environments, each with its pre-defined weight. In the DQCMC method the resulting equations are similar to that of the first-order CMC, and the “diffusion in the mixture fraction space” term is strictly positive and no correction factors are used. Results have been presented for two mixing environments, where the resulting matrices of the DQCMC can be inverted analytically. Initially the DQCMC is tested for a simple hydrogen flame using a multi species chemical scheme containing nine species. The effects of the fluctuations around the conditional means are captured qualitatively and the predicted results are in very good agreement with observed trends from direct numerical simulations (DNS). To extend the analysis further and validate the model for larger hydrocarbon fuel, the simulations have been performed for n-heptane flame using detailed multi species chemical scheme containing 67 species. The hydrocarbon fuel showed improved results in comparison to the simple hydrogen flame. It suggests that higher hydrocarbons are more sensitive to local scalar dissipation rate and the fluctuations around the conditional means than the hydrogen. Finally, the DQCMC is coupled with a semi-empirical soot model to study the effects of particulate formation such as soot. The modelling results show to predict qualitatively the trends from DNS and are in very good agreement with available experimental data from a shock tube concerning ignition delays time. Furthermore, the findings suggest that the DQCMC approach is a promising framework for soot modelling.
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Robertson, Duncan A. "The strategy hypercube : a dynamic model for inter-firm competition and the generation of profit landscapes in turbulent environments." Thesis, University of Oxford, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.416766.
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Avó, Marcos Rocha de. "Estratégia em tempos turbulentos: a realidade das empresas familiares vista através do ramo de alcool combustível brasileiro." reponame:Repositório Institucional do FGV, 2008. http://hdl.handle.net/10438/2272.
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Previous issue date: 2008-07-18T00:00:00ZThis dissertation deals with strategy of family firms in turbulent environments, aiming to particularly explore two research questions: (1) how do family businesses from traditional family sectors consider the impact of environmental turbulences over the industry’s family dimension?; (2) which is the family firms’ strategic behavior, considering their family dimension, in a turbulent environment? Strategy in turbulent contexts has been studied for more than two decades. However, the focus on the family businesses’ strategic behavior in this kind of context is still unexplored on the literature. Based on two case studies, one in a large company and another in a small one, and on an inductive approach, the research questions were explored. The Brazilian sugar-ethanol sector, during the period 2003-2008, is the context for this research. Beyond being traditionally composed by family firms, this industry is characterized by significant turbulences, during the period, especially due to demand growth and to the expectation related to a bigger improvement in the near future. The turbulent environment is completed by pressures on the companies’ operational scale, new entrants, new investments and consolidation movements. The results show that the main impacts on the family dimension are pressures for family firms’ professionalization and for the owner’s mindset change, especially in respect to funding and control solutions. These pressures have the potential to create generalized movements among the industry’s family firms, making the results an important contribution for the understanding about turbulences. For the family firms’ strategic behavior in turbulent environments, the results suggest, first, that strategies in this kind of environment include the family dimension, which is greatly related to control consolidation and professionalization solutions, considering rules for succession among other factors. Professionalization in family firms in turbulent environments can have functional or symbolic roles, including the company’s exposure to external stakeholders. Finally, the results show that the studied companies’ strategies, in relation to professionalization, are a set of elements conceived by diverse theoretical perspectives (agency theory, firm’s growth theory, stewardship theory and resourcebased view). Through these theories, it is possible to better understand the main components from each strategy, being pro or against professionalization.
Este trabalho trata da estratégia de empresas familiares em ramos turbulentos, procurando explorar especialmente duas questões: (1) como empresas familiares situadas em ramo tradicionalmente familiar contemplam o possível impacto de turbulências setoriais sobre a dimensão familiar do ramo?; (2) qual o comportamento estratégico de empresas familiares, considerando sua dimensão familiar, num ambiente turbulento? A estratégia em contextos turbulentos tem sido objeto de pesquisa há pouco mais de duas décadas. O foco, no entanto, no comportamento estratégico das empresas familiares, nesse tipo de contexto, é ainda inédito na literatura. Através de dois estudos de caso, com uma empresa de grande porte e uma de pequeno porte, e sob uma abordagem indutiva de teoria, as questões foram exploradas. O ramo sucro-alcooleiro brasileiro, no período de 2003 a 2008, foi o contexto adotado para desenvolver o trabalho. Além de ser tradicionalmente formado por empresas familiares, o setor é marcado, no período citado, por turbulências, especialmente em relação ao crescimento da demanda e à expectativa de maior crescimento no futuro próximo. O ambiente turbulento é completado por pressões para aumento da escala das empresas do ramo, atração de entrantes, novos investimentos na capacidade de operação e movimentos de consolidação. Os resultados indicam que os principais impactos do ambiente turbulento na dimensão familiar do ramo são pressões para a profissionalização das empresas familiares e para a mudança no mindset dos controladores dessas empresas, especialmente no tocante a soluções de funding e de controle. Essas pressões têm potencial de gerarem movimentos generalizados entre as empresas familiares do ramo, tornando os resultados uma contribuição importante ao entendimento das turbulências. Quanto ao comportamento estratégico das empresas familiares no contexto turbulento, os resultados sugerem, primeiramente, que a dimensão familiar faz parte das estratégias dessas empresas nesse tipo de ambiente e está, em grande medida, relacionada a soluções de consolidação do controle e de profissionalização, incluindo o estabelecimento de regras de sucessão. A profissionalização de empresas familiares em ambientes turbulentos pode ter um papel funcional ou simbólico, de exposição da empresa para stakeholders externos. Por fim, os resultados mostram que as estratégias das empresas estudadas, no que tocante à profissionalização, são a composição de elementos previstos por diferentes perspectivas teóricas (teoria da agência, teoria do crescimento da firma, stewardship theory e resource-based view), sendo possível analisar, através de tais perspectivas, os componentes que mais se destacam em cada estratégia, sejam favoráveis ou contrários à profissionalização.
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Bitlloch, Puigvert Pau. "Turbulent bubble suspensions and crystal growth in microgravity. Drop tower experiments and numerical simulations." Doctoral thesis, Universitat de Barcelona, 2012. http://hdl.handle.net/10803/96295.
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We study the formation and spreading of a turbulent jet of bubbles in microgravity. This has been analyzed from the recordings obtained in previous experimental campaigns of microgravity. Results have been compared with a simplified model of passive bubbles, in which bubbles are advected by the mean flow and dispersed due to the local degree of turbulence at each point of the jet. Thanks to the expertise obtained with this part of the thesis, we have designed and built a new experiment that has been used 36 times in the 4.7 s drop tower of ZARM (“Center of Applied Space Technology and Microgravity”) in Bremen. With this experiment we have obtained, for the first time in history, a monodisperse suspension of bubbles, within a turbulent flow, in microgravity. From the resulting measures we have characterized the relaxation time of pseudo-turbulence (previously generated due to the effect of buoyancy forces upon the injected bubbles in normal gravity conditions). We have also studied the interaction between bubbles and the turbulent medium. Results have been compared with Lattice-Boltzmann simulations of the flow.
On the other hand, we have also studied the impact of residual gravitational vibrations (known as g-jitters) upon the quality of semiconductors solidified in microgravity. The quality of the resulting crystals has been studied from the analysis of the inhomogeneities in their dopant concentration. This study has been based entirely on simulations, but g-jitters have been modeled from acceleration signals measured in real space missions.En la present tesi s’estudia, en primer lloc, la formació d’un doll turbulent de bombolles en condicions de microgravetat. Aquest ha sigut analitzat a partir del tractament de les gravacions obtingudes per altres investigadors en experiments de microgravetat. Els resultats s’han comparat amb un model simplificat de bombolles passives, en el que aquestes són arrossegades pel flux mitjà i, simultàniament, són dispersades degut al grau local de turbulència a cada punt. Gràcies a la experiència obtinguda en aquest anàlisi, s’ha dissenyat un nou experiment que ha sigut utilitzat en 36 llançaments de la torre de caiguda de 4.7 segons del ZARM (“Centre de Tecnologia Espacial Aplicada i Microgravetat”) a Bremen. Amb aquest experiment s’ha aconseguit, per primera vegada a la història, una suspensió monodispersa de bombolles, en el sí d’un flux turbulent, en condicions de microgravetat. A partir dels resultats obtinguts, s’ha caracteritzat per primera vegada el temps de relaxació de la pseudo-turulència (generada prèviament degut a l’efecte de les forces de flotació sobre les bombolles injectades en gravetat normal). També s’ha estudiat l’efecte causat per les bombolles en el medi turbulent. Els resultats han sigut comparats amb simulacions realitzades mitjançant el model de Lattice-Boltzmann. Per altra banda, s’ha estudiat també l’efecte que tenen les vibracions gravitatòries residuals sobre la qualitat de semiconductors solidificats en microgravetat. S’ha analitzat la qualitat dels cristalls resultants a partir de l’estudi de les inhomogeneïtats en la concentració de dopant. Aquest estudi ha sigut realitzat íntegrament a base de simulacions, però s’han establert els paràmetres dominants del soroll gravitatori a partir de valors mesurats en missions espacials reals.
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Lacassagne, Tom. "Oscillating grid turbulence and its influence on gas liquid mass transfer and mixing in non-Newtonian media." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEI103/document.
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L’étude du transfert de masse turbulent aux interfaces gaz-liquide est d’un grand intérêt dans de nombreuses applications environnementales et industrielles. Bien que ce problème soit étudié depuis de nombreuses années, sa compréhension n’est pas encore suffisante pour la création de modèles de transfert de masse réalistes (de type RANS ou LES sous maille), en particulier en présence d’une phase liquide à rhéologie complexe. Ce travail expérimental a pour but l’étude des aspects fondamentaux du transfert de masse turbulent à une interface plane horizontale entre du dioxyde de carbone gazeux et une phase liquide newtonienne ou non, agitée par une turbulence homogène quasi isotrope. Les milieux liquides non newtoniens étudiés sont des solutions aqueuses d’un polymère dilué à des concentrations variables et aux propriétés viscoélastiques et rhéofluidifiantes. Deux méthodes de mesure optiques permettant l’obtention du champ de vitesse de la phase liquide (SPIV) et de concentration du gaz dissout (I-PLIF) sont couplées tout en maintenant une haute résolution spatiale, afin de déduire les statistiques de vitesse et de concentration couplées dans les premiers millimètres sous la surface. Une nouvelle version de I-PLIF est développée pour les mesures en proche surface. Elle peut également s’appliquer dans différentes études de transfert de masse. La turbulence de fond est générée par un dispositif de grille oscillante. Les mécanismes de production et les caractéristiques de la turbulence sont étudiés. L’importance de la composante oscillante de la turbulence est discutée, et un phénomène d’amplification de l’écoulement moyen est mis en évidence. Les mécanismes du transfert de masse turbulent à l’interface sont finalement observés pour l’eau et une solution de polymère dilué à faible concentration. L’analyse conditionnelle des flux de masse turbulent permet de mettre en évidence les évènements contribuant au transfert de masse et de discuter de leur impact relatif sur le transfert totalThe study of turbulence induced mass transfer at the interface between a gas and a liquid is of great interest in many environmental phenomena and industrial processes. Even though this issue has already been studied for several decades, its understanding is still not good enough to create realistic models (RANS or sub-grid LES), especially when considering a liquid phase with a complex rheology. This experimental work aims at studying fundamental aspects of turbulent mass transfer at a flat interface between carbon dioxide and a Newtonian or non-Newtonian liquid, stirred by homogeneous and quasi isotropic turbulence. Non-Newtonian fluids studied are aqueous solutions of a model polymer, Xanthan gum (XG), at various concentrations, showing viscoelastic and shear-thinning properties. Optical techniques for the acquisition of the liquid phase velocity field (Stereoscopic Particle Image Velocimetry, SPIV) and dissolved gas concentration field (Inhibited Planar Laser Induced Fluorescence, I-PLIF) are for the first time coupled, keeping a high spatial resolution, to access velocity and concentration statistics in the first few millimetres under the interface. A new version of I-PLIF is developed. It is designed to be more efficient for near surface measurements, but its use can be generalized to other single or multiphase mass transfer situations. Bottom shear turbulence in the liquid phase is generated by an oscillating grid apparatus. The mechanisms of turbulence production and the characteristics of oscillating grid turbulence (OGT) are studied. The importance of the oscillatory component of turbulence is discussed. A mean flow enhancement effect upon polymer addition is evidenced. The mechanisms of turbulent mass transfer at a flat interface are finally observed in water and low concentration polymer solutions. A conditional analysis of turbulent mass fluxes allows to distinguish the type of events contributing to mass transfer and discuss their respective impact in water and polymer solutions
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Westerberg, Mats. "Managing in turbulence : an empirical study of small firms operating in a turbulent environment." Doctoral thesis, Luleå tekniska universitet, Innovation och Design, 1998. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-18430.
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This thesis deals with how small firms, and especially their CEOs, manage their situation in times of high environmental turbulence. Eight firms have been chosen for the empirical study based on their performance and the CEO’s self-efficacy and tolerance for ambiguity. Interviews with the CEO and employees at each firm, observations, gathering of annual reports and a questionnaire are the principal means used for data collection. The results show that the CEO is very influential at all firms, regardless how the company performs. A CEO that tolerate uncertainty is better able to engage in enterprising, which seems necessary in turbulence. A CEO with high self- efficacy is generally able to control his firms destiny by having access to the appropriate resources for the task (e.g. own ability and network). However, too high self-efficacy could be a sign of dysfunctional overconfidence, where the CEO dismiss relevant information from actors around him.Godkänd; 1998; 20061120 (haneit)
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Hübner, Jens. "Buoyant plumes in a turbulent environment." Thesis, University of Cambridge, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.603909.
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This dissertation investigates how a nominally axisymmetric plume is affected by the presence of ambient turbulence. The results of this investigation are based on laboratory experiments in water. The experiments employ a saline plume released downwards into a tank of fresh water with an oscillating grid positioned near the bottom. A wide range of regimes with increasing levels of ambient turbulence is covered from a quiescent environment to the eventual break-up of the plume. Buoyancy and velocity data were obtained using fluorescent dye and particle tracking, respectively. The response of a plume to ambient turbulence is found to be twofold. The plume centreline position deviates from the perfect vertical and the plume spreading relative to that centreline position increases. Both mechanisms, plume "meandering" and "spreading", combine to create a time averaged plume image in which the plume appears wider. Sophisticated image processing techniques are developed to disentangle the two mechanisms and to quantify their respective contributions to the overall plume spreading. The turbulence-induced plume meandering scales on the ratio of the transversal velocity fluctuation of the background turbulence to the vertical mean velocity on the plume centreline. A simple extension to classical plume theory is proposed to account for the increased plume spreading via enhanced entrainment that becomes dependent on the strength of the ambient turbulence. Although in a quiescent environment the cross-sectional profiles of velocity and buoyancy are close to Gaussian in shape, the actual mechanism of plume spreading involves an inwards erosion of the Gaussian shape from the flanks of the profile by the ambient turbulence. Obviously, a simple extension to classical plume theory does not capture this qualitative change to the shape of the plume profiles. A scaling is proposed instead that links the radial extent to which the Gaussian profile is eroded by the ambient turbulence to the relative magnitudes of the fluctuating velocity in the ambient turbulence and on the centreline of a plume in a quiescent environment.
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Hedlöf, Carina, and Ulrika Janson. "How to cope with a turbulent environment." Thesis, Linköping University, Department of Management and Economics, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-567.
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Background: Due to constant changes and unpredictability in a turbulent environment, the traditional way of planning does not seem to work anymore. Therefore, new approaches to the external and internal conditions need to develop in order to cope with the environmental turbulence.
Purpose: The purpose of this thesis is to define a turbulent environment and identify how an organisation can cope with this environment. Procedure: We have developed a frame of reference mainly consisting of theories regarding a turbulent environment and change. In addition, we have selected eight guiding factors, which we have used when studying, systemising, and comparing how contemporary literature suggests that an organisation can cope with a turbulent environment.
Results: The conclusions we have come to are that with a definition of the environment as being fast-changing and of chaotic nature, where the changes are continuous, emergent, small, big or somewhere in between, and where paradoxes play an important role, it is necessary to develop an organisational structure, leadership, human resource, and corporate culture, in which the objective always is to create dynamics and to build in an acceptance of change.
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Renoud, Robert W. "Boundary layer response to an unsteady turbulent environment." Thesis, Monterey, California. Naval Postgraduate School, 1988. http://hdl.handle.net/10945/22931.
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Bosco, Carol. "The Relationship Between Environmental Turbulence, Workforce Agility and Patient Outcomes." Diss., The University of Arizona, 2007. http://hdl.handle.net/10150/195013.
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For years heath care workers have been dealing with environmental changes which have created turbulent, complex work environments. Turbulence has been considered a negative phenomenon. However Workforce Agility may be a positive response to Environmental Turbulence. Other disciplines are familiar with the term Turbulence and Workforce Agility but there is little research available on this concept despite the impact that they may have on patient outcomes.The purpose of this research was to identify the relationship between Environmental Turbulence, Workforce Agility and Patient Outcomes through the examination of four alternative theoretical models.This research was conducted using secondary analysis of the IMPACT data set (Verran, Effken & Lamb, 2001-2004). The data were reanalyzed in order to answer different questions than the primary study. Causal modeling with path analysis and regression analysis was conducted to answer the research questions. Three questions included the use of either a moderator variable or mediator variable.The setting for the IMPACT Study was acute care hospitals in the Southwestern region of the United States. For the IMPACT study, the sample consisted of patient care units from teaching and non-teaching hospitals. Subjects consisted of staff members who were employed on the patient care units.Data collected from the Registered Nurses were used for the secondary analysis because this research was interested in looking primarily at the nursing unit. The total RN staff assigned to patient care units who responded to the questionnaires was N=454. The total number of patients who responded to the survey was N=1179.In summary, the unit characteristics that were found to be Antecedents to ET were the sub-composites of Team and Complexity. Proxy variables, Collaborative Culture Agility and Experiential Agility, were successfully formed as a composite for WFA and were tested with the primary data. No mediators or moderators were shown; however, main effects of WFA and ET did have an impact on patient outcomes.
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Gwilliam, David J. "Separating boundary layer response to an unsteady turbulent environment." Thesis, Monterey, California. Naval Postgraduate School, 1989. http://hdl.handle.net/10945/27259.
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Tavakoli, Behtash. "Numerical simulation of particle-laden turbulent flows-Environmental applications." Thesis, Clarkson University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3700373.
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In first part of the thesis a detailed study of the particulate pollutant distribution by wind flow over a building in an urban area was performed. The accuracy of RANS-RSTM and LES turbulence models for predicted airflow over a square cylinder was first evaluated. These models are then applied for simulating wind flows over the scale-model of the Center of Excellence (CoE) Building. Comparing the simulation results with the experimental data of Kehs et al. (2009) showed that the RSTM predicted the pressure distribution on the building consistent with the measurements, but it could not capture the details of the airflow velocity field around the building. The LES simulation, however, showed good agreement with the PIV data. The LES model was then used for analyzing the particulate pollutants transport and deposition analysis.
Particle motion was modeled using a one-way coupling, Lagrangian approach. Particular attentions were given to the effect of the turbulent velocity fluctuations on particles dispersion and deposition. Instantaneous turbulent velocity fluctuations were simulated using the Langevin stochastic differential equation. The particle transport model in turbulent flows was validated by comparing the predicted deposition velocity for vertical and horizontal channel flows with the existing experimental data and numerical simulation results. Finally the particulate pollutant dispersion and deposition around the scaled CoE Building were investigated using the LES and unsteady particle tracking approach.
In addition, the size-concentration distribution of secondary organic aerosols (SOAs), as an indoor air aldehyde pollutant, was numerically modeled. The population balance equation of the SOAs was solved using the method of moments (MOM). To close the model, particle size distribution was assumed to follow a lognormal distribution, which was based on the experimental data of Chen and Hopke (2009). The nucleation of SOAs from the chemical reaction of &agr;-pinene (a common emission from indoor furniture), and ozone in the air, as well as, their Brownian coagulation and the surface growth were considered in the numerical model. The computational model was evaluated by comparison with the experimental data of Chen and Hopke (2009).
The MOM was used for modeling the distribution of the SOAs in an office space. The concentrations of SOAs in the breathing zone of an occupant in the room were evaluated for two mixed-mode ventilation systems. The simulation results showed that the pollution concentration in the ventilation system with the air outlet placed in the ceiling was smaller than the one in which the air outlet was in the floor behind the manikin model.
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Barreto-Acobe, Clary Denisse 1976. "Turbulent wave-current boundary layers revisited." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/84239.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2001.Includes bibliographical references (leaves 91-94).
by Clary Denisse Barreto-Acobe.
S.M.
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Read, Simon. "Transition to turbulence in a turbomachinery environment." Thesis, Cranfield University, 1997. http://dspace.lib.cranfield.ac.uk/handle/1826/10509.
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This thesis aims to contribute to the understanding of transitional flows in
the blade boundary layers of axial compressors. Two experiments are described,
the first examining in detail the transitional boundary layer on a
simulated controlled-diffusion blade and the second surveying the mid-height
flowfield in an embedded
stage of a low-speed axial compressor. The velocity
distribution on the simulated blade is identical to the Velocity distribution on
the suction surface of the blades in the axial compressor.
At 2
Reynolds numbers and 3 levels of freestream turbulence, a single hot
wire was used to conduct a boundary layer survey on a simulated controlled-diffusion
blade.
Integral parameters of the boundary layers are explored to
dene the
length and nature of transition.
At low Reynolds number there is a separated or near separated region at the
leading edge which does not lead to turbulence. Transition covers a length of
approximately 20% of the blade chord, starting between 20% and 30% chord.
The
position of transition is strongly influenced by the level of freestream
turbulence. Most of the transition process occurs within the decelerating flow
region which exists from 20% of the chord. At high Reynolds number, a leading
edge separation bubble leads to transition within 2% of the blade chord.
Abu-Ghannam & Shaws correlation for the start and length of transition
was found to
predict the start of transition well for attached flows, but could
not be relied
upon for separated flows. It is apparent that the correlation was
not
designed for the very strong Velocity gradients in the leading edge region,
and
probably not for separated flow. _
Three flow conditions in the axial compressor were used: design speed, peak
efficiency, low Reynolds number at peak efficiency (the machine was slowed
to
one-quarter speed) and design speed near the stall. Using hot wires at
mid-height, axial and circumferential velocity and turbulence information was
obtained.
Wakes and structure within wakes are visible in the turbulence and Reynolds
stress distributions. The wakes of more than one upstream blade row are visible;
the region where two wakes intersect gives some information about interaction
between a stator blade Wake and a rotor blade boundary layer. Some
information is available about the length scale 'distribution inside and outside
wakes.
Secondary flow in the axial-circumferential plane shows motion within
wakes and a vortex in the near-stall flowfield, shed preferentially at one point
in the
blade-passing cycle.
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Newman, Paul Lockwood. "Numerical simulation of diffusive shock acceleration in a turbulent astrophysical environment." Thesis, Imperial College London, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307793.
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Fairbank, Nicola. "Viral infection and predation of phytoplankton residing in a turbulent environment." Thesis, University of Liverpool, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.548765.
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Xu, Ying. "Flow/acoustic interactions in porous media under a turbulent wind environment." Diss., Manhattan, Kan. : Kansas State University, 2010. http://hdl.handle.net/2097/3510.
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Machin, Alison Isabel. "Role identity in a turbulent environment : the case of health visiting." Thesis, University of Newcastle upon Tyne, 2009. http://hdl.handle.net/10443/3972.
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This thesis presents a grounded theory study of UK health visitors practising in an increasingly integrated, collaborative, service user focused healthcare system. Emphasis is placed in policy on a preventative, public health approach to addressing the ongoing health needs of the population. This has provoked a national debate on the healthcare contribution of health visitors. Better use of health visiting capacity and closer alignment of the role with the collaborative public health agenda have been identified as a national priority. The theoretical framework for this study has been developed from the symbolic interactionist premise, that individuals continually reinterpret their world in the context of their social interaction with others. Data has been collected from direct observation and individual interviews. The process of constant comparative analysis has generated four interrelated data categories: professional role in action; interprofessional working; local micro systems for practice and professional role identity (core category). Three models have been developed to support the discussion of the findings. The first two make explicit the inter-relationship between the concepts identified in the data and interactive processes relating to the maintenance of identity. The third model proposes a process of interprofessional role change. It links the uniprofessional and interprofessional dimensions of practice to the core principle of valuing individuals through the maintenance of equilibrium in their professional role identity. Embedding a process for feedback on identity is identified as important. This thesis theorises that role change facilitation should enable individuals to continually renegotiate their professional role identity in the context of their practice. It also suggests that promoting a sense of collective identity within a professional group will enhance the experience of individuals involved in a collaborative role change process. The thesis concludes with a consideration of its implications for health visiting and others in the healthcare system, in seeking to maintain their role identity in a turbulent practice environment.
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Matulka, Anna Magdalena. "Turbulent structure in environmental flows: effects of stratification and rotation." Doctoral thesis, Universitat Politècnica de Catalunya, 2010. http://hdl.handle.net/10803/52809.
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Several series of experiments in stratified and in rotating/stratified decaying flows after a grid is used to stir the two layer stable fluid
brine and fresh water set up. We measure by comparing the gained potential energy with the available kinetic energy AKE, the
relative efficiency of mixing. The experiments in stratified rotating flows with grid driven turbulence were both periodic (quasi
stationary) and non-monotonic (decaying) forcing. This thesis compares experimental, numerical and field observations on the
structure and Topology of the Stratified Rotating Flows as well as their decay, the horizontal spectra changes appreciable with
slopes from 1.1 to 5, but vorticity and local circulation, and also the initial topology and forcing of the flow.
A detailed study of the vorticity decay and vortex and energy structure has been performed, the new results show that neither
stratified nor rotating flows exhibit pure 2D structures. The work parameterizes the role of the Richardson number and the Rossby
number, both in the experiments and in the ocean visualizations is very important. The conditions of vortex decay show the effects of
the internal waves in the decay turbulent conditions both for stratified and rotating flows. The parameter space (Re,Ri,Ro) has been
used to interpret many previously disconnected explanations of the 2D-3D turbulent behaviour. The comparison of numerical
simulations with experiments has allowed implementing new theoretical aspects of the interaction between waves and vortices
finding the surprising and very interesting result that these interactions depend on the level of enstrophy. This also leads to new
ways of using multifractal analysis ad intermittency in ocean environmental observations.
A large collection of SAR images obtained from three European coastal areas were used for routine satellite analysis by SAR and
other sensors, which seem very important to build seasonal databases of the dynamic conditions of ocean mixing. The topology of
the basic flow is very important and in particular the topology of the vortices and their decay which depends on ambient factors such
as wave activity, wind and currents. We find more realistic estimates of the spatial/temporal non-homogeneities (and intermittency
obtained as spatial correlations of the turbulent dissipation); these values are used to parameterize the sea surface turbulence, as
well as a laboratory experiments at a variety of scales.
Using multi-fractal geometry as well, we can establish now a theoretical pattern for the turbulence behaviour that is reflected in the
different descriptors. Vorticity evolution is smoother and different than that of scalar or tracer density. The correlation between the
local Ri and the fractal dimension detected from energy or entropy is good. Using multi-fractal geometry we can also establish
certain regions of higher local activity used to establish the geometry of the turbulence mixing that needs to be studied in detail when
interpreting the complex balance between the direct 3D Kolmogorov type cascade and the Inverse 2D Kraichnan type cascade.
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Braz, Vanessa de Almeida. "Práticas de manufatura ágil e performance operacional." Master's thesis, Instituto Superior de Economia e Gestão, 2014. http://hdl.handle.net/10400.5/7537.
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Mestrado em Gestão e Estratégia IndustrialDurante décadas assumiram-se a múltiplas filosofias de gestão direcionadas para a produção magra e em massa de forma a responder a ineficiências de processo e ao consumismo desenfreado, otimizando custos operacionais. No entanto, novas filosofias de customização e produções flexíveis têm vindo a ganhar terreno em algumas indústrias, como é o caso da manufatura ágil. A partir de uma revisão de literatura que aborda desde a história desta filosofia aos seus contornos e (escassos) casos práticos identificados, segue-se uma abordagem metodológica exploratória, com entrevistas semiestruturadas a três casos de estudo. O objetivo é estudar quais são as práticas da manufatura ágil que estão a ser aplicadas nas empresas estudadas e que efeito se perceciona que as mesmas tenham na performance operacional. Os resultados do estudo apontam para a aplicação de algumas das práticas da manufatura ágil mesmo que os gestores não tenham perceção que as mesmas estão associadas a esta filosofia. Concluiu-se também, através da constatação dos inquiridos que na sua opinião as práticas ágeis contribuem de forma positiva para a performance operacional das empresas. Por serem ainda poucos os casos exploratórios na literatura da manufatura ágil e nenhum deles efetuado em Portugal (até à data deste TFM), assume-se o carácter original deste estudo.
For decades multiple management philosophies directed towards lean production and mass were assumed as to respond to process inefficiencies and rampant consumerism, optimizing operation costs. However, new customization and flexible productions philosophies have been gaining ground in some industries, such as the agile manufacturing. From a literature review that addresses everything from the history of this philosophy to their contours and (scarce) identified practical cases, followed by an exploratory methodology approach, with three semi-structured case study interviews. The goal is to study which of agile manufacturing practices are being applied in the studied companies and what is the perceived effect that these have on operational performance. The study results indicate that some of the agile manufacturing practices are applied even if managers do not have the same perception that the practices are associated with this philosophy. It was also concluded, by the finding through respondents opinions, that agile practices contribute positively to the studied companies operating performance. Because the exploratory cases are few in the literature of agile manufacturing and none of them made in Portugal (until the date of this masters final thesi), it is assumed the original character of this study.
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Herlina. "Gas transfer at the air-water interface in a turbulent flow environment." Karlsruhe : Univ.-Verl, 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=976595842.
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Genin, Franklin Marie. "Study of compressible turbulent flows in supersonic environment by large-eddy simulation." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28085.
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Thesis (M. S.)--Aerospace Engineering, Georgia Institute of Technology, 2009.Committee Chair: Menon, Suresh; Committee Member: Ruffin, Stephen; Committee Member: Sankar, Lakshmi; Committee Member: Seitzman, Jerry; Committee Member: Stoesser, Thorsten
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Zahroon, Sinan, and Linus Rydén. "Snabbväxande företag i föränderliga miljöer : En kvalitativ flerfallstudie om tillväxt och styrning i snabbväxande företag." Thesis, Linnéuniversitetet, Institutionen för ekonomistyrning och logistik (ELO), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-96881.
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Bakgrund och problem: Vikten av de snabbväxande företagens påverkan på marknaden är något som på senare tid fått extra uppmärksamhet. Andelen snabbväxande företag i Sverige är hög jämfört med andra länder, men bara en liten del lyckas fortsätta överleva på lång sikt. Detta sker på grund av att företagen befinner sig i föränderliga miljöer som många av dessa snabbväxande företagen inte lyckas anpassa sig till samt klara av utmaningarna som uppstår vid tillväxt. Syfte: Syftet med denna studie är att få en djupare förståelse för hur omgivningen påverkar styrningen i snabbväxande företag som befinner sig i föränderliga miljöer. Vidare sökes en förståelse kring hur företagen agerar för att växa och hur tillväxten påverkar utvecklingen av styrningen i företagen. Metod: Baserat på syftet och de valda forskningsfrågorna valdes en flerfallstudie som forskningsdesign. De tre fallen som valdes består av svenska företag som under en kort period upplevt en mycket hög tillväxt. Semistrukturerade intervjuer valdes för insamling av empirin. Slutsats: Studiens resultat tyder på att externa faktorer såsom digitalisering, konjunkturförändringar, politik och media har tvingat företagen att utvecklas från tidigare arbetssätt till en tydligare planering av verksamheten. De valda strategierna för snabb tillväxt är att antingen öka försäljningen eller expandera geografiskt. Det konstaterades att externa faktorer som politiska beslut kan möjliggöra tillväxten samt interna faktorer som viljan för tillväxt och kompetens driver tillväxten framåt. Dessutom konstaterades legitimitet vara en intern faktor som möjliggör tillväxt.Background and problem: The importance of the influence of fast-growing companies in the market is something that has recently received extra attention. The proportion of fast-growing companies in Sweden is high compared to other countries, but only a small number manage to survive in the long term. This is due to the fact that companies are in turbulent environments that many of these fast-growing companies are unable to adapt to and meet the challenges posed by growth. Purpose: The aim of this study is to gain a deeper understanding of how the environment affects the governance of fast-growing companies that are in changing environments. Furthermore, an understanding is sought of how companies act to grow and how growth affects the development of corporate governance. Method: A multiple case study was selected as a research design based on the purpose and the selected research questions. The three cases selected consist of Swedish companies that experienced very high growth in a short period. Semi-structured interviews were selected for the collection of the empirical data. Conclusion: The study's findings indicate that external factors such as digitalization, business cycles, politics and the media have forced companies to evolve from previous work methods to a formal planning of the business. The chosen strategies for rapid growth are to either increase sales or expand geographically. It was found that external factors such as political decisions may enable growth as well as internal factors such as the will for growth and competence to drive growth. In addition, legitimacy was found to be an internal factor enabling growth.
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Yuan, Jing Ph D. Massachusetts Institute of Technology. "Experimental and theoretical study of turbulent oscillatory boundary layers." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/85821.
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Thesis: Ph. D. in Environmental Fluid Mechanics, Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 241-244).
Sediment transport is of crucial importance to engineering projects in coastal regions, so it is of primary interest in coastal engineering. The driving forces for sediment transport are mostly determined by the hydrodynamics of oscillatory turbulent bottom boundary layers, which is still not well understood. Therefore, the goal of this thesis is to improve the present experimental and theoretical understandings on this subject. A high-quality experimental study including a large number of tests which correspond to full-scale coastal boundary layer flows is performed using a state-of-the-art oscillating water tunnel (OWT) for flow generations and a Particle Image Velocimetry system for velocity measurements. The experimental results suggest that the logarithmic profile can accurately represent the boundary layer flows in the very near-bottom region, so the log-profile fitting analysis can give highly accurate determinations of the hydrodynamic roughness, the theoretical bottom location and the bottom shear stress. The current velocity profiles in the presence of sinusoidal waves indicate a two-log-profile structure suggested by the widely-used Grant-Madsen model. However, for weak currents in the presence of nonlinear waves, the two-log-profile structure is contaminated or even totally obliterated by the boundary layer streaming which is related with the temporal variation of the turbulent eddy viscosity. This, together with some other experimental evidence, motivates the development of a new theoretical model which adopts a rigorous way to account for a time-varying turbulent eddy viscosity. The model accurately predicts the mean and leading Fourier components of the velocity and the bottom shear stress for various flow conditions. Most importantly, the boundary layer streaming related to the time-varying turbulent eddy viscosity is reasonably predicted, which leads to successful predictions of the mean velocity embedded in nonlinear-wave tests and the current velocity profiles in the presence of either sinusoidal or nonlinear waves. The predictions reveal significant differences between boundary layer flows in OWTs and in the coastal environment, which must be considered when interpreting OWT results for sediment transport.
by Jing Yuan.
Ph. D. in Environmental Fluid Mechanics
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Heimar, Markus, and Daniel Nilsson. "Survival in Chaos: A Study of Strategy Formation in a Turbulent Business Environment." Thesis, Linköping University, Department of Management and Economics, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-1498.
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Since the late 1960’s, the hydromechanical term turbulence has been a part of the business administration vocabulary, but until the late 1980’s and early 1990’s, a relatively small amount of research was dedicated to this field. These studies and more contemporary ones conclude that where the business environment is paradoxical and of fast- changing and chaotic nature, successful corporate strategies are shaped by strategic flexibility founded in high innovation rates, networks and alliances, and organisational elasticity and adaptiveness. From this perspective, the purpose of this study was to track and examine the strategy formation processes of a company operating in a turbulent context, and to contribute to an understanding of how these turbulent conditions can be managed. The study was conducted with a hermeneutic, systems- oriented, longitudinal case-study method and with a contextcontent- process perspective in which the process was the key factor. To a large extent, our conclusions coincide with those of other researchers. Forming multidimensional networks and alliances coloured by voluntary initiatives and full attention seem to be an extremely important contribution to survival in turbulent contexts. Nevertheless, it is equally important to break up and build new alliances as the initial objectives of the arrangement have expired or been reached. Furthermore, in contrast to other researchers’ observations, we conclude that high innovation rates do not necessarily lead to a greater potential to be successful in a turbulent context. The issue is instead to present a product offering flexible in itself developed and marketed by a flexible organisation. Innovation rates are decided by self-initiated and unofficial activity on part of the r&d teams and other coworkers, and management’s task is to facilitate for this corporate creativity to develop.
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Mason, Roger Bruce. "Product tactics in a complex and turbulent environment viewed through a complexity lens." The Business Review, Cambridge, 2012. http://hdl.handle.net/10321/1169.
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This paper is based on the proposition that the choice of different product tactics is influenced by the nature of the firm’s external environment. It illustrates the type of product activities suggested for a complex and turbulent environment, when viewing the environment through a chaos and complexity theory lens. A qualitative, case method, using depth interviews,investigated the product activities in two companies to identify the product activities adopted in a more successful, versus a less successful, firm in a complex/turbulent environment. The results showed that the more successful company uses some destabilizing product activities but also partially uses stabilizing product activities. These findings are of benefit to marketers as they emphasize a new way to consider future product activities in their firms. Since businesses and markets are complex adaptive systems, using complexity theory to understand how to cope in complex, turbulent environments is necessary, but has not been widely researched, with even less emphasis on individual components of the marketing mix.
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Onishi, Ryo. "Numerical simulations of chemical reaction and droplet growth in environmental turbulent flows." 京都大学 (Kyoto University), 2005. http://hdl.handle.net/2433/144912.
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Barrantes, Analía Inés. "Turbulent boundary layer flow over two-dimensional bottom roughness elements." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/42585.
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Wedell, Martin. "Managing educational change in a turbulent environment : the ELTSUP project in Hungary, 1991-1998." Thesis, University of South Wales, 2000. https://pure.southwales.ac.uk/en/studentthesis/managing-educational-change-in-a-turbulent-environment(c80d02c6-0c4f-4819-95d7-a00e6d4bac8c).html.
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One result of the political changes in Hungary in 1989-90, was the sudden switch, within state education, from compulsory study of Russian to a free choice of foreign languages. Most pupils (or their parents) opted to study English or German. Opportunities to study these languages in schools had previously been limited, and consequently there was a severe shortage of trained teachers. The English Language Teacher Supply (ELTSUP) project, was established by formal agreement between the British Council and the Hungarian Ministry of Education and Culture to counter this shortage through the provision of new, three year, initial language teacher training programmes, at nine Hungarian tertiary institutions. ELTSUP's rationale, and initial stated wider objectives were principally quantitative; to increase the supply of trained English teachers to the state education system and so the number of students able to learn English. By the mid 1990s, due principally to the 'turbulence' referred to in the title, it was clear that the above aim would not be met. Project objectives, now became qualitative; the integration of three year programme curriculum change into the existing, still largely unchanged, philologically focussed, four and five year language teacher education system. The thesis is a longitudinal, single case study. Its aim is to investigate and analyse the educational change process in one ELTSUP institution between 1991 and 1998. From 1993- 1998, the writer was employed by the British Council at the case study institution. He was thus a participant observer (Marshall and Rossman 1989, Yin 1989), throughout the data collection period. The research is grounded in educational and organisational change literature, particularly the work of Fullan (1991,1992,1993) Louis and Miles (1992), Whittaker (1993), Harris et al (1997), Pettigrew and Whipp (1991), Hatch (1997), Webb and Cleary (1994), and the qualitative research writings of Lincoln and Guba (1985), Denzin and Lincoln (1994), Erlandson et al (1993), Coffey and Atkinson (1996) and Crossley and Vulliamy (1997). It is an inductive qualitative study, based initially upon 'etic' and later upon "emic 1 issues (Stake 1995), and consequently had a research focus that evolved throughout the two years of the data gathering cycle. The three main sources of data are semi-structured interviews, questionnaires and project documents. The core data consists of interviews, carried out in three rounds over a two-year period with those most centrally involved, the 10 Hungarian implementers of the project. In addition, 22 other people closely connected to ELTSUP, at either national or institutional level, were interviewed. Questionnaires, sent out to past and present students, their school supervisors and other British Council contract staff in Hungary, were used to provide further evidence about the wider Hungarian environment and to corroborate interview data. As a participant in the changes under investigation the writer had access to all English language project related documentation, throughout the case study period. Data was analysed using a two dimensional framework based on Fullan's (1991) chronological division of the stages of the educational change process, Planning- Implementation-Continuation, and the components of any organisational change process suggested by Pettigrew and Whipp (1991), Content, Context and Process. Together these gave a nine cell matrix, allowing data first to be mapped and then analysed, broadly as suggested by Miles and Huberman (1994). The main findings include: On educational change projects involving more than one educational culture, and where one educational culture is accepted as bringing with it expertise that the other lacks, aims can never remain purely quantitative. Qualitative educational change is cultural change. It is therefore complex and takes a long time. It is rare to find measurable, direct evidence of success in the short-term. The necessarily long time scale and the unpredictability of the behaviour of the wider The necessarily long time scale and the unpredictability of the behaviour of the wider environment, make detailed advance planning of the change implementation process impracticable. Educational change is an evolving and incremental process. The rate and route of change followed throughout the implementation process is likely to be strongly influenced by, often unpredictable, occurrences at all levels of the environment. If change is ever to begin to become part of the wider educational culture beyond the project, local implementers need to be consistently supported throughout their personal change process. For such consistency to be possible, change instigators need, at the initial planning stage, to understand both what is realistically possible and what their roles within the project are likely to be. They thus need, in outline at least, to understand both the micro and wider change environments. Environmental assessment need not be complex to be valuable. It does, however, need to be continuously updated to take account of changes in the wider environment. Cultural change is hard work for those experiencing it. Perceptions of its utility can quickly become negative, without tangible recognition for work done, and periods of stability in which to consolidate new skills. Change instigators, expecting (and expected) to operate in a world that increasingly seeks rapid, measurable returns on any investment, find most of the above very difficult to accept.
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Church, Jeffrey H. (Jeffrey Harrison). "The use of turbulent jets to destratify the Charles River Basin." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/73794.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2012.Page 74 blank. Cataloged from PDF version of thesis.
Includes bibliographical references (p. 72-73).
This study examines the feasibility of using turbulent jets to destratify the Lower Charles River Basin between the Longfellow and Craigie Bridges between Boston and Cambridge. The basin is currently filled with salt water that intrudes from the downstream dam and the resulting vertical density gradients inhibit mixing, leading to low levels of dissolved oxygen at depth. A physical model was scaled to a portion of this basin and salt water was used to create initial density profiles. Turbulent jets were introduced near the bottom at varying flow rates, discharge angles, and nozzle diameters, and a conductivity probe was used to document changes in salinity versus elevation and time. The effectiveness of the turbulent mixing was determined by comparing the change in water column potential energy over time, while efficiency was determined by comparing the change in potential energy versus the cumulative input of kinetic energy. The most effective arrangement provided a scaled mixing time of about a week to mix the basin. Since this is significantly shorter than the (annual) period over which stratification takes place, it is concluded that the turbulent jets would be an effective method to destratify the basin.
by Jeffrey H. Church.
S.M.
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[Verfasser], Herlina. "Gas transfer at the air-water interface in a turbulent flow environment / von Herlina." Karlsruhe : Univ.-Verl. Karlsruhe, 2005. http://d-nb.info/976595842/34.
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Christen, Andreas. "Atmospheric turbulence and surface energy exchange in urban environments : results from the Basel Urban Boundary Layer Experiment (BUBBLE) /." Basel : Institut für Meteorologie, Klimatologie und Fernerkundung (MCR Lab) der Universität Basel : in Komm. bei Wepf, 2005. http://edoc.unibas.ch/diss/DissB_7159.
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Wall, Dylan Joseph. "Anisotropic Turbulence Models for Wakes in an Active Ocean Environment." Diss., Virginia Tech, 2021. http://hdl.handle.net/10919/104162.
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A set of second-moment closure turbulence models are implemented for the study of wake evolution in an oceanic environment. The effects of density stratification are considered, and the models are validated against laboratory experiments mimicking the stratified ocean environment, and against previous experimental study of wakes subjected to a density stratification. The turbulence models are found to reproduce a number of important behaviors which differentiate stratified wakes from those in a homogeneous environment, including the appropriate decay rates in turbulence quantities, buoyant suppression of turbulence length scales, and canonical stages in wake evolution. The existence of background turbulence is considered both through the introduction of production terms to the turbulence model equations and the replication of scale-resolved simulations of wakes embedded in turbulence. It is found that the freestream turbulence causes accelerated wake growth and faster decay of wake momentum. Wakes are then simulated at a variety of Re and Fr representative of full-scale vehicles operating in an ocean environment, to downstream distances several orders of magnitude greater than existing RANS studies. The models are used to make some general predictions concerning the dependence of late-wake behavior on these parameters, and specific insights into expected behavior are gained. The wake turbulence is classified using "fossil turbulence" and stratification strength criteria from the literature. In keeping with experimentally observed behavior, the stratification is predicted to increase wake persistence. It is also predicted that, regardless of initial Re or F r, the wake turbulence quickly becomes a mixture of overturning eddies and internal waves. It is found that the high Re wakes eventually become strongly affected by the stratification, and enter the strongly-stratified or LAST regime. Additional model improvements are proposed based on the predicted late wake behavior.Doctor of Philosophy
A set of advanced turbulence models are implemented and used to study ship wakes in an oceanic environment. The flows in the ocean are subject to a density stratification due to changes in temperature and salinity; the associated effects are included in the turbulence models. The models are validated against laboratory experiments mimicking the stratified ocean environment, and against previous experimental study of wakes subjected to a density stratification. The turbulence models are found to reproduce a number of important behaviors expected under such conditions based on experimental study. Additional modifications are made to the models to include the effect of pre-existing freestream turbulence. Wakes are then simulated under conditions representative of full-scale vehicles operating in an ocean environment. The models are used to make some general predictions concerning late-wake behavior. Specific insights into expected behavior are gained. The wake turbulence is classified using ``fossil turbulence'' and stratification strength criteria from the literature. In keeping with experimentally observed behavior, the stratification is predicted to increase wake persistence. Additional model improvements are proposed based on the predicted late wake behavior.
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Choksi, Kashyap Nalin. "A Strategic Approach to Managing Turbulence in the Normative Environment." Diss., Virginia Tech, 2004. http://hdl.handle.net/10919/29508.
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One of the central areas of focus in organizational theory that has been of particular interest is the organization-environment interface. While various theories have made vital contributions to the study of organization-environment relations, their emphasis on organization adaptation is varied. However, research and practice have amply demonstrated that organizations do not exist in a vacuum; that if an organization is to survive and meet its goals, it has to adapt to or somehow make accommodations with its cognitive and normative environment.
This study explores the issue of an organization trying to adapt to its normative environment by deeply examining the situation of a national private nonprofit organization, with ties to the land-grant university and college system, which found itself in the midst of a turbulent environment. Specifically, the study discusses how that nonprofit was affected by this turbulence when it accepted funding from the nation's largest tobacco company to develop and implement a tobacco prevention program. The act of this nonprofit accepting funds from the tobacco corporation caused challenges in internal management, worsened relations with some of its core constituencies, and fomented discord within leading non-profit organizations. The notion of turbulence, the mechanism of isomorphism as espoused by the new institutionalists, and the role of agency was explored, supplemented by a strategic approach that included components of contracting standards that organizations could adapt to attain congruency with elements of their turbulent normative environment. In particular, this strategic approach utilized a framework borrowed from research conducted by Oliver (1991), emphasizing strategies of Defiance, Manipulation and Avoidance. What this study offers is a strategic approach to help non-profit organizations when they partner with a controversial source of funding, especially in cases where they are faced with these kinds of management dilemmas.Ph. D.