Dissertations / Theses on the topic 'Natural Hazards not elsewhere classified'

The aim of this work is to explore means to improve the speed of the computational electromagnetics (CEM) processing in use for aircraft design and certification work by a factor of 1000 or so. The investigation addresses particularly the set of problems described as electromagnetic hazards comprising lightning, EMC and the illumination of an aircraft by external radio sources or HIRF (high intensity radiated fields). These are areas which are very much aspects of the engineering of the aircraft where the requirement for accuracy of simulations is of the order of 6dB as build and test repeatability cannot achieve better than this. Computer simulations of these interactions at the outset of this work were often taking 10 days and more on the largest parallel computers then available in the UK (Cray T3D - 40 GFLOPS nominal peak). Such run times made any form of optimisation impossibly lengthy. While the future offered the certain prospect of more powerful computers, the simulations had to become more comprehensive in their representation of materials and features, geometry of the object, and particularly the representation of wires and cables had to improve radically, and tum around times for analysis had to be improved for design assessment as well as to make design optimisation by trade-off studies feasible. All of these could easily consume all the advantage that the new computers would give. The investigation has centred around techniques that might be applied via alteration to the most widely used and usable numerical methods in CEM applied to the electromagnetic hazards, and to techniques that might be applied to the manner of their use. In one case, the investigation has explored a particular possibility for minimising the duration of computation and extrapolating the resulting data to the longest time-scales required. Future improvements in the capabilities of radiating boundary conditions to mimic the effect of an infinite boundary at close range will further improve the benefits already established in this work, but this is not yet realisable. However, it has been established that a combination of techniques with some processes devised through this work can and does deliver the performance improvement sought. It has further been shown that the issues such as object resonance that could have incurred significant error and distrust of computational results can be satisfactorily overcome within the required accuracy. Four papers have been published arsing from this work. Some of these techniques are now in use in routine analyses contributing to BAE SYSTEMS programmes. Plans are in place to incorporate all of the successful techniques and processes.

Natural hazards cause enormous amounts of damage worldwide every year. Since 1994 more than 1.35 billion people have lost their lives and more than 116 million homes have been damaged. Understanding of disaster risk implies knowledge about vulnerability, capacity, exposure of persons and assets, hazard characteristics and the environment. Quantitative damage assessments are a fundamental part of disaster risk management. There are, however, substantial challenges when quantifying damage which depends on the diversity of hazards and the fact that one hazardous event can negatively impact a society in multiple ways. The overall aim of the thesis is to analyze the relationship between climate-related natural hazards and subsequent damage for the purpose of improving the prerequisite for quantitative risk assessments in the future. The thesis concentrates on two specific types of consequences due to two types of hazards, 1) damage to buildings caused by lake floods, and 2) loss of lives caused by quick clay landslides.  Several causal relationships were established between risk factors and the extent of damages. Lake water levels increased the probability of structural building damage. Private damage reducing measures decreased the probability of structural building damage. Extent of damage decreased with distance to waterfront but increased with longer flood duration while prewar houses suffered lower flood damage compared to others. Concerning landslides, the number of fatalities increased when the number of humans in the exposed population increased. The main challenges to further damage estimation are data scarcity, insufficient detail level and the fact that the data are rarely systematically collected for scientific purposes. More efforts are needed to create structured, homogeneous and detailed damage databases with corresponding risk factors in order to further develop quantitative damage assessment of natural hazards in a Nordic perspective.
Naturolyckor orsakar enorma mängder skador över hela världen varje år. Under åren 1994-2013 förlorade mer än 1,35 miljoner människor sina liv och mer än 116 miljoner hem skadades. Förståelse av risk för naturolyckor innebär kunskap om sårbarhet, kapacitet, exponering av personer och tillgångar, hot och miljö. Kvantitativa skadebedömningar, som är en viktig del av riskbedömningar, omfattas av stora utmaningar som grundar sig i hotens mångfaldighet och det faktum att en naturolycka kan påverka ett samhälle negativt på många olika sätt. Det övergripande syftet med avhandlingen är att analysera förhållandet mellan naturkatastrofer och potentiellt påföljande skador i syfte att förbättra förutsättningarna för kvantitativa riskbedömningar i framtiden. Avhandlingen koncentrerar sig på två typer av naturolyckor med specifika konsekvenser, 1) skador på byggnader till följd av sjö-översvämningar, och 2) förlust av liv orsakat av lerskred. Flera orsakssamband mellan riskfaktorer och omfattning av skador har identifierats. Sjöarnas vattennivåer ökade sannolikheten att drabbas av strukturell byggnadsskada, samtidigt som privat initierade åtgärder minskande sannolikheten.. När avstånd mellan sjö och byggnad ökade minskade omfattningen av översvämningsskador, men ökade ju längre sjööversvämningen varade. Hus byggda före 1940 fick mindre skador jämfört med andra hus. Andelen dödsfall i samband med skred i kvicklera ökade när antal människor i den exponerade befolkningen ökade. Den största utmaningen i att förbättra dagens kvantitativa skadebedömningar är den rådande databristen vad gäller förluster och tillhörande riskfaktorer. Denna brist beror på otillgänglig skadedata, bristande detaljnivå på skadedata och tillhörande risk faktorer, och att uppgifterna sällan samlas systematiskt i syfte att studera kausalitet.
The overall aim of the thesis is to analyze the relationship between climate-related natural hazards and subsequent damage for the purpose of improving the prerequisite for quantitative risk assessments in the future. The thesis concentrates on two specific types of hazards with specific types of consequences, 1) damage to buildings caused by lake floods, and 2) loss of lives caused by quick clay landslides.  Several causal relationships were established between risk factors and the extent of damages. Lake water levels increased the probability of structural building damage. Private damage reducing measures decreased the probability of structural building damage. Extent of damage decreased with distance to waterfront but increased with longer flood duration while prewar houses suffered lower flood damage compared to others. Concerning landslides, the number of fatalities increased when the number of humans in the exposed population increased. The main challenges to further damage estimation are data scarcity, insufficient detail level and the fact that the data are rarely systematically collected for scientific purposes.

Research has consistently demonstrated that exposure to nature, as opposed to urban environments, can be beneficial to health and wellbeing. Among natural landscapes, aquatic (blue space) scenes are among the most preferred and psychologically restorative. Since such landscapes face an increasing range of demands, there is a need to understand how their restorative qualities arise and might be preserved, both in terms of the content of a scene and the psychological processes involved in its interpretation. This thesis examines the cognitive impact of placing artificial (human-made) objects in natural landscapes with and without water. It reports new findings regarding the importance of specific scene content for the restorative potential of blue space. The research also explores some of the underlying psychological processes, addressing novel questions about implicit (subconscious) attitudes towards natural landscapes. It compares implicit and explicit attitudes for the first time in this context. In four studies, methods from social and experimental psychology were used to investigate attitudes towards blue and green space with and without artificial objects. To examine the issues of both artificial objects and implicit attitudes, Study 1 used the Affect Misattribution Procedure (which measures implicit attitudes towards images) to assess whether implicit affect (subconscious positive or negative emotion) differed when the same natural scene was viewed with and without artificial objects. Results showed that introducing objects into natural scenes had a negative impact on implicit affect, particularly when the scene contained water. In order to be able to compare implicit and explicit attitudes, Study 2 examined explicit affective reactions to the images from Study 1 using questions adapted from the Perceived Restorativeness Scale (a measure of the restorative potential of environments). Blue space scenes were rated more highly than green space scenes on all components except aesthetics. The presence of artificial objects resulted in lower ratings on all measures for both blue and green scenes. Study 3 was motivated by an indication in the results from Study 1 that implicit attitudes towards blue and green space may differ. The Affect Misattribution Procedure was used to investigate this for natural landscapes without artificial objects. The study also examined whether implicit attitudes differ according to the type of blue or green environment. Viewing blue space scenes resulted in more positive implicit affect than green space, with sea views generating the most positive implicit affect of all. Following the discovery that artificial objects had a more negative impact on implicit attitudes to blue space than green space, Study 4 tested the possibility that this could be due to such objects being more disruptive to the conceptual coherence of aquatic scenes. The conceptual-semantic congruence of artificial objects was assessed using a lexical decision task, in which participants reacted to object words superimposed on scenes. Results did not support the hypothesis that artificial objects are less congruent in blue space than green space. Overall, the studies provide evidence that placing artificial objects in natural landscapes, particularly aquatic landscapes, adversely affects both implicit and explicit attitudes towards the scenes and may reduce their restorative potential. By successfully combining methods from social and experimental psychology, this research validates novel ways of formulating and addressing questions about why some environments have a more positive psychological impact than others. The new results reported here are not easily explained by current restorative theory, therefore might contribute to refining the theoretical framework within which restorative environments are studied.

The subject of this project is natural history specimens and the exploration of their qualities in visual artwork. The first part is a 533cm watercolour painting composed of an image of at least one specimen (or part thereof) to represent each flowering plant family, of which there are 505. The ‘Herbarium Specimen Painting’ was created using dried plant specimens from the herbarium collection at the Royal Botanic Gardens, Kew. The plant families are painted in systematic order following one of the recently developed DNA classification systems. The painting was produced with scientific rigor and under the constant supervision of Kew botanists. It aims not only to illustrate the chosen classification system but to explore the aesthetic beauty of herbarium specimens and celebrate many of the incredible and varied narratives contained within the Kew collection. The second element of this thesis constructs a context for the above artwork among similar projects. Natural history institutions worldwide were contacted for information about artists using natural history collections to produce art with a strong narrative element that ‘discussed’ the notion of the specimen. These artists were then contacted and many interviewed. In parallel, the literature review concentrated on theories developed in the field of material culture where the human relationships between groups of objects are analysed. These theories proved fundamental and on occasion inspirational in uncovering deeper meanings and narrative possibilities. The concluding section of this research discusses whether the findings of this project, which uses and develops material culture theory can contribute to that field of research. It analyses the possibility that specimen-based artwork can benefit science and/or help revitalise museum collections, and comments on whether institutions can improve the public communicability of the objects in their care by treating them as a potential source for new art.

Technology is becoming pervasive and the current interfaces are not adequate for the interaction with the smart environments of the ubiquitous computing era. Recently, researchers have started to address this issue introducing the concept of natural user interface, which is mainly based on gestural interactions. Many issues are still open in this emerging domain and, in particular, there is a lack of common guidelines for coherent implementation of gestural interfaces. This research investigates gestural interactions between humans and smart environments. It proposes a novel framework for the high-level organization of the context information. The framework is conceived to provide the support for a novel approach using functional gestures to reduce the gesture ambiguity and the number of gestures in taxonomies and improve the usability. In order to validate this framework, a proof-of-concept has been developed. A prototype has been developed by implementing a novel method for the view-invariant recognition of deictic and dynamic gestures. Tests have been conducted to assess the gesture recognition accuracy and the usability of the interfaces developed following the proposed framework. The results show that the method provides optimal gesture recognition from very different view-points whilst the usability tests have yielded high scores. Further investigation on the context information has been performed tackling the problem of user status. It is intended as human activity and a technique based on an innovative application of electromyography is proposed. The tests show that the proposed technique has achieved good activity recognition accuracy. The context is treated also as system status. In ubiquitous computing, the system can adopt different paradigms: wearable, environmental and pervasive. A novel paradigm, called synergistic paradigm, is presented combining the advantages of the wearable and environmental paradigms. Moreover, it augments the interaction possibilities of the user and ensures better gesture recognition accuracy than with the other paradigms.

In urbanized river basins, sanitary wastewater and urban runoff (non-sanitary water) from urban agglomerations drain to complex engineered networks, are treated at centralized wastewater treatment plants (WWTPs) and discharged to river networks. Discharge from multiple WWTPs distributed in urbanized river basins contributes to impairments of river water-quality and aquatic ecosystem integrity. The size and location of WWTPs are determined by spatial patterns of population in urban agglomerations within a river basin. Economic and engineering constraints determine the combination of wastewater treatment technologies used to meet required environmental regulatory standards for treated wastewater discharged to river networks. Thus, it is necessary to understand the natural-human-engineered networks as coupled systems, to characterize their interrelations, and to understand emergent spatiotemporal patterns and scaling of geochemical and ecological responses.

My PhD research involved data-model synthesis, using publicly available data and application of well-established network analysis/modeling synthesis approaches. I present the scope and specific subjects of my PhD project by employing the Drivers-Pressures-Status-Impacts-Responses (DPSIR) framework. The defined research scope is organized as three main themes: (1) River network and urban drainage networks (Foundation-Pathway of Pressures); (2) River network, human population, and WWTPs (Foundation-Drivers-Pathway of Pressures); and (3) Nutrient loads and their impacts at reach- and basin-scales (Pressures-Impacts).

Three inter-related research topics are: (1) the similarities and differences in scaling and topology of engineered urban drainage networks (UDNs) in two cities, and UDN evolution over decades; (2) the scaling and spatial organization of three attributes: human population (POP), population equivalents (PE; the aggregated population served by each WWTP), and the number/sizes of WWTPs using geo-referenced data for WWTPs in three large urbanized basins in Germany; and (3) the scaling of nutrient loads (P and N) discharged from ~845 WWTPs (five class-sizes) in urbanized Weser River basin in Germany, and likely water-quality impacts from point- and diffuse- nutrient sources.

I investigate the UDN scaling using two power-law scaling characteristics widely employed for river networks: (1) Hack’s law (length-area power-law relationship), and (2) exceedance probability distribution of upstream contributing area. For the smallest UDNs, length-area scales linearly, but power-law scaling emerges as the UDNs grow. While area-exceedance plots for river networks are abruptly truncated, those for UDNs display exponential tempering. The tempering parameter decreases as the UDNs grow, implying that the distribution evolves in time to resemble those for river networks. However, the power-law exponent for mature UDNs tends to be larger than the range reported for river networks. Differences in generative processes and engineering design constraints contribute to observed differences in the evolution of UDNs and river networks, including subnet heterogeneity and non-random branching.

In this study, I also examine the spatial patterns of POP, PE, and WWTPs from two perspectives by employing fractal river networks as structural platforms: spatial hierarchy (stream order) and patterns along longitudinal flow paths (width function). I propose three dimensionless scaling indices to quantify: (1) human settlement preferences by stream order, (2) non-sanitary flow contribution to total wastewater treated at WWTPs, and (3) degree of centralization in WWTPs locations. I select as case studies three large urbanized river basins (Weser, Elbe, and Rhine), home to about 70% of the population in Germany. Across the three river basins, the study shows scale-invariant distributions for each of the three attributes with stream order, quantified using extended Horton scaling ratios; a weak downstream clustering of POP in the three basins. Variations in PE clustering among different class-sizes of WWTPs reflect the size, number, and locations of urban agglomerations in these catchments.

WWTP effluents have impacts on hydrologic attributes and water quality of receiving river bodies at the reach- and basin-scales. I analyze the adverse impacts of WWTP discharges for the Weser River basin (Germany), at two steady river discharge conditions (median flow; low-flow). This study shows that significant variability in treated wastewater discharge within and among different five class-sizes WWTPs, and variability of river discharge within the stream order <3, contribute to large variations in capacity to dilute WWTP nutrient loads. For the median flow, reach-scale water quality impairment assessed by nutrient concentration is likely at 136 (~16%) locations for P and 15 locations (~2%) for N. About 90% of the impaired locations are the stream order < 3. At basin-scale analysis, considering in stream uptake resulted 225 (~27%) P-impaired streams, which was ~5% reduction from considering only dilution. This result suggests the dominant role of dilution in the Weser River basin. Under the low flow conditions, water quality impaired locations are likely double than the median flow status for the analyses. This study for the Weser River basin reveals that the role of in-stream uptake diminishes along the flow paths, while dilution in larger streams (4≤ stream order ≤7) minimizes the impact of WWTP loads.

Furthermore, I investigate eutrophication risk from spatially heterogeneous diffuse- and point-source P loads in the Weser River basin, using the basin-scale network model with in-stream losses (nutrient uptake).Considering long-term shifts in P loads for three representative periods, my analysis shows that P loads from diffuse-sources, mainly from agricultural areas, played a dominant role in contributing to eutrophication risk since 2000s, because of ~87% reduction of point-source P loads compared to 1980s through the implementation of the EU WFD. Nevertheless, point-sources discharged to smaller streams (stream order < 3) pose amplification effects on water quality impairment, consistent with the reach-scale analyses only for WWTPs effluents. Comparing to the long-term water quality monitoring data, I demonstrate that point-sources loads are the primary contributors for eutrophication in smaller streams, whereas diffuse-source loads mainly from agricultural areas address eutrophication in larger streams. The results are reflective of spatial patterns of WWTPs and land cover in the Weser River basin.

Through data-model synthesis, I identify the characteristics of the coupled natural (rivers) – humans – engineered (urban drainage infrastructure) systems (CNHES), inspired by analogy, coexistence, and causality across the coupled networks in urbanized river basins. The quantitative measures and the basin-scale network model presented in my PhD project could extend to other large urbanized basins for better understanding the spatial distribution patterns of the CNHES and the resultant impacts on river water-quality impairment.

COS and CS₂ are sulfur compounds that are formed in natural waters. These compounds are also volatile, which leads them move into the atmosphere and serve as critical precursors to sulfate aerosols. Sulfate aerosols are known to counteract global warming by reflecting solar radiation. One major source of COS and CS₂ stems from the ocean. While previous studies have linked COS and CS₂ formation in these waters to the indirect photolysis of organic sulfur compounds, much of the chemistry behind how this occurs remains unclear. This study examined this chemistry by evaluating how different organic sulfur precursors, water quality constituents, and temperature affected COS and CS₂ formation in natural waters.

In the first part of this thesis (chapters 2 and 3), nine natural waters ranging in salinity were spiked with various organic sulfur precursors (e.g. cysteine, cystine, dimethylsulfide (DMS) and methionine) exposed to simulated sunlight over varying exposures. Other water quality conditions including the presence of O₂, CO and temperature were also varied. Results indicated that COS and CS₂ formation increased up to 11× and 4×, respectively, after 12 h of sunlight while diurnal cycling exhibited varied effects. COS and CS₂ formation were also strongly affected by the DOC concentration, organic sulfur precursor type, O₂ concentration, and temperature while salinity differences and CO addition did not play a significant role.

To then specifically evaluate the role of DOM in cleaner matrices, COS and CS₂ formation was examined in synthetic waters (see chapters 4 and 5). In this case, synthetic waters were spiked with different types of DOM isolates ranging from freshwater to ocean water along with either cysteine or DMS and exposed to simulated sunlight for up to 4 h. Surprisingly, CS₂ was not formed under any of the tested conditions, indicating that other water quality constituents, aside from DOM, were responsible for its formation. However, COS formation was observed. Interestingly, COS formation with cysteine was fairly similar for all DOM types, but increasing DOM concentration actually decreased formation. This is likely due to the dual role of DOM on simultaneously forming and quenching the reactive intermediates (RIs). Additional experiments with quenching agents to RIs (e.g. ³DOM* and ·OH) further indicated that ·OH was not involved in COS formation with cysteine but ³DOM* was involved. This result differed with DMS in that ·OH and ³DOM* were both found to be involved. In addition, treating DOM isolates with sodium borohydride (NaBH₄) to reduce ketone/aldehydes to their corresponding alcohols increased COS formation, which implied that the RIs formed by these functional groups in DOM were not involved. The alcohols formed by this process were not likely to act as quenching agents since they have been shown to low in reactivity. Since ketones are known to form high-energy-triplet-states of DOM while quinones are known to form low-energy-triplet-states of DOM, removing ketones from the system further supported the role of low-energy-triplet-states on COS formation. This was initially hypothesized by findings from the testes on DOM types. In the end there are several major research contributions from this thesis. First, cysteine and DMS have different mechanisms for forming COS. Second, adding O₂ decreased COS formation, but it did not stop it completely, which suggests that further research is required to evaluate the role of RI in the presence of O₂. Lastly, considering the low formation yields of COS and CS₂ formation from the organic sulfur precursors tested in this study, it is believed that some other organic sulfur precursors are missing which are likely to generate these compounds to higher levels and this needs to be investigated in future research.

This thesis research is concerned with the exploration, design, and validation of novel haptic technologies and signals that feel natural and meaningful in a calm and pleasant way. Our ultimate goal is to expand the possibilities of human-machine interaction by developing a single tactile display and a set of signals through a systematic design approach. It is generally a challenge to evoke a broad range of emotions with vibrotactile stimulation, especially at low signal intensities. During the first part of this thesis research, three types of prototypes were developed and explored using novel haptic technologies. The first was a circular array braille display consisting of eight small six-pin braille modules. The forty-eight pins were arranged in a circular shape to deliver circular tactile information such as time and direction. The second was a braille stick consisting of sixteen six-pin braille modules arranged in a row. The entire display could be easily grasped in the hand so that tactile information can be easily accessible. The third was a 3-by-3 electroactive polymer actuator array driven at high voltages that gives a subtle “tapping” feel on the skin. However, each of the three prototypes suffered from a limited range of expression and was not pursued further.
After the initial prototyping efforts, a 2-by-2 vibrotactile display, the palmScape, was conceived and developed. Custom-designed stimulation patterns based on natural phenomena that feel calm and pleasant were designed and implemented with the palmScape. We use text labels to set the context for the vibrotactile icons that attempt to capture and expresses natural metaphors through variations in signal amplitude, frequency, duration, rhythm, modulation, spatial extent, as well as slow movements. Fourteen participants evaluated twenty vibrotactile icons by rating the perceived valence and arousal levels. The twenty stimuli included sixteen custom-designed vibrotactile icons from this thesis research and four reference patterns from two published studies. The results show that our custom-designed patterns were rated at higher valence levels than the corresponding reference signals at similar arousal ratings. Five of the sixteen vibrotactile icons from this research occupied the fourth quadrant of the valence-arousal space that corresponds to calm and pleasant signals. These findings support the validity of the palmScape display and our signal design approach for achieving a calm and pleasant experience and the possibility of reaching a broader range of expressiveness with vibrotactile signals.
Future studies will continue with the design of signals that can express a broader range of metaphors and emotions through the palmScape, and build an emotional evaluation database that can be combined with other modalities. Our work can be further expanded to support an immersive experience with naturalistic-feeling vibrotactile effects and broaden the expressiveness of human-computer interfaces in media consumption, gaming, and other communicative application domains.

The hydrogen bond is one of nature’s ubiquitous molecular interactions. Its role ranges from that of a static provider of structural integrity in proteins to that of a dynamic coordinate, along which excited state deactivation in sunscreen molecules is achieved. The work in this dissertation employs a supersonic expansion to collisionally cool peptide oligomers and a sunscreen chromophore to the zero-point vibrational level of their low lying conformational minima. These species are interrogated using high-resolution, conformer-specific ultraviolet and infrared laser spectroscopic techniques with the aim of elucidating their intrinsic conformational preferences, hydrogen bonding networks, and excited state deactivation mechanisms.

Synthetic foldamers are oligomers composed of non-natural building blocks, such as b- and g-amino acids. Incorporation of such residues into a peptide backbone results in secondary and tertiary structures that are distinct from those found in nature. Herein, the folding propensity of a series of mixed a/b and pure b-peptides is presented. In each case, both the left- and right-handed emergence of mixed-helical secondary structures, the 11/9- and the 12/10-helix, are observed. Next, the intrinsic conformational preferences of a series of increasingly complex asparagine-containing peptides are characterized. Asparagine, with its flexible carboxamide sidechain, is omnipresent within the prion forming domain of the misfolded proteins associated with several neurodegenerative diseases. Asparagine’s propensity for b-turn structures is discussed and compared with that of analogous peptide sequences found in nature.

Methyl anthranilate is a natural product that contains an identical electronic chromophore to the sunscreen agent, meradimate. The excited state deactivation mechanism of methyl anthranilate and its water complex is determined with extensive ultraviolet spectroscopic characterization, and is discussed within the broader context of its role as a sunscreen agent. Vibronic analysis coupled with computational results indicate extensive heavy-atom rearrangement leading to hydrogen atom dislocation, rather than full transfer, on the S₁ surface. This phenomenon is further characterized with infrared spectroscopy and theoretical modeling, in which the NH stretch is adiabatically separated from other internal coordinates. Extensive dilution of the dislocated NH stretch oscillator strength over many transitions and ~1,300 cm^-1 is predicted. These results may have implications for similar molecules, such as salicylic acid and its derivatives.

Combustion phenomena are complex in theory and expensive to test, analysis techniques
provide handles with which we may describe them. Just as simultaneous experimental tech-
niques provide complementary descriptions of flame behavior, one might assume that no
analysis technique for any kind of flame measurement would cover the full description of
the flame. To this end, the search continues for complementary descriptions of engineering
flames that capture enough information for the engine designer to make informed decisions.
The kinds of flames I have encountered are high pressure transverse jet flames issuing into a
vitiated crossflow which is itself generated from combustion of a gaseous fuel and oxidizer.
Summarizing the behavior of these flames has required my understanding of experimen-
tal techniques such as Planar Laser Induced Fluorescence of a reaction intermediate -OH,
Particle Image Velocimetry of a passive tracer in the flame and OH * chemiluminescence of
another reaction intermediate. The analysis tools applied to these measurements must reveal
as much information as is laden in these measurements.
In this work I have also used wavelet optical flow to track flow features in the visualization
of combustion intermediates using OH * chemiluminescence. There are many limitations to
the application of this technique to engineering flames especially due to the interpretation
of the data as a 2-D motion field in 3-D world. The interpretation of such motion fields
as generated by scalar fields is one subject matter discussed in this dissertation. Some
inferences from the topology of the ensuing velocity field has provided insight to the behavior
of reacting turbulent flows which appear attached to an injector in the mean field. It gives
some understanding to the robustness of the attachment mechanism when such flames are
located near walls.

Resilience is studied as a systemic property in several disciplines such as engineering, psychology, systems biology, and ecological sciences. Yet, the system view on resilience is not pervasive in management science. This dissertation is on Enterprise Resilience, which is an emerging topic within the fields of organization and management science. Corporate enterprises are viewed as type 1 complex adaptive systems (CAS) operating within an external business environment. Thus, perturbations occurring in the environment affect enterprises, whose resilience then depends on their adaptive response to them. Therefore, the focus is on system perturbances and on investigating drivers of the enterprises’ adaptive response. As a result, enterprise resilience is more granularly defined as an enterprise’s ability to continually remain valuable to stakeholders by simultaneously managing short-term shocks and long-term stressors. This re-definition brings forth an actionable pathway to enterprise resilience- the pursuit of improved management of the enterprise’s risk and growth management functions.

Two challenging issues plaguing the risk and growth functions are the lack of a comprehensive understanding of risks (especially of unknowns) and their inter-connections, and a weak link between risk management and the enterprise’s growth strategy intended to continually and increasingly generate value. This work addresses both issues via the development of an enterprise-agnostic comprehensive risk typology, and by building a conceptual link between risk and growth strategy through the business model construct and its use in the study of repeatable patterns of innovation. Therefore, this work develops one pathway toward enterprise resilience i.e., via improved risk management and systematic growth management. Furthermore, it advances knowledge by bridging the theoretical conceptualization of an enterprise as a CAS1 into actionable methods for practice in the form of risk management tools and systematic innovation frameworks that aid the enterprise’s adaptive response.

The interdisciplinary dissertation develops hypotheses and employs appropriate qualitative and quantitative methods to test them. Overall, a theory building process is undertaken using the constructionist school of thought and using methods based in inductive logic such as the scholarship of integration, thematic analysis, and case studies. Additionally, to achieve wide and comprehensive coverage, data-driven quantitative methods using advanced computing such as data mining, machine learning, and natural language processing are employed.