Although emergency management is established for the purpose of addressing disasters and other major emergencies, I have found that it can be purposefully engineered to also be an assist leader to other agencies and entities during nonemergency periods because the key element of synchrony that enables emergency managers to be effective during an emergency can also be employed during nonemergency periods to assist other departments in a manner that not only delivers a direct benefit to the department but also enhances the emergency preparedness, mitigation, and resiliency efforts of the jurisdiction. Emergency managers can create this performance-enhancing synchrony using boundary spanning functions that bridge the divide that separates stakeholders. Emergency management practitioners are steadfast in their pursuit of methods and practices by which they can be more effective. The recent increase in the frequency and severity of natural disasters is only one example of the ever-growing demands placed upon these professionals. Compounding this development is the fact that the occurrences of natural disasters have outpaced research and theory development regarding how emergency management professionals should prepare for and respond to these events. This research study envisions, proposes, and outlines a framework in which emergency managers function in a broader capacity that could elevate their overall performance and importance to a higher plane than the one on which perhaps most currently operate. / Business Administration/Strategic Management

The upcoming Laser Interferometer Space Antenna (LISA) is expected to detect gravitational waves (GWs) from massive black hole binaries (MBHB). Finding the electromagnetic (EM) counterparts for these GW events will be crucial for understanding how and where MBHBs merge, measuring their redshifts, constraining the Hubble constant and the graviton mass, and for other novel science applications. However, due to poor GW sky localization, multi-wavelength, time-dependent electromagnetic (EM) models are needed to identify the right host galaxy. This dissertation investigates electromagnetic (EM) signatures to accompany compact black hole binaries, specifically those that occur prior to, during, and following the merger, as well as those originating via self-lensing flares (SLFs). Chapter 2 considers equal-mass merging massive black hole binaries (MBHBs) embedded in a circumbinary disk (CBD), using high-resolution two-dimensional simulations, with a 𝚪-law equation of state, incorporating viscous heating, shock heating, and radiative cooling. Beginning from before the decoupling limit and transitioning through into post-merger, distinct EM features are identified before, during, and after the merger. The main result is that the MBHB produces strong thermal X-ray emission until 1-2 days prior to the merger. However, as the binary decouples from the CBD, the X-ray-bright minidisks rapidly shrink in size, become disrupted, and the accretion rate drops precipitously. As a result, the thermal X-ray luminosity drops by orders of magnitude, and the source remains X-ray dark for several days, regardless of any post-merger effects such as gravitational wave (GW) recoil or mass loss. Looking for this abrupt spectral change where the thermal X-ray disappears is a tell-tale EM signature of LISA mergers that does not require extensive pre-merger monitoring. Chapter 3 follows up on and extends the results of Chapter~\ref{chap:ch2} by investigating the effects to the EM spectrum for unequal-mass MBHBs via comparable simulations. This work corroborates the findings of a several order of magnitude drop in the thermal X-ray luminosity near the time of merger, but with delayed timing than found in an equal-mass system, while the source still remains X-ray dark for hours post-merger. The main result, however, is a new signature, a sharp spike in the thermal X-ray emission just before the tell-tale steep drop occurs. This adds an additional EM signature that can be used to identify EM counterparts of LISA's unequal MBHBs before the merger and potentially measure the mass ratio of the system through EM means. Finally, Chapter 4 addresses the EM signature of self-lensing flares (SLFs). SLFs are expected to be produced once or twice per orbit by an accreting MBHB, if the eclipsing MBHBs are observed close to edge-on. Again, using high-resolution two-dimensional viscous hydrodynamical simulations of a CBD embedding a MBHB, a very high-cadence output of these hydrodynamical simulation is used as inputs for a general-relativistic ray-tracing code to produce synthetic spectra and phase-folded light curves. The main results show a significant periodic amplification of the flux with the characteristic shape of a sharp flare with a central dip, as the foreground black hole (BH) transits across the minidisk and shadow of the background BH, respectively. These corroborate previous conclusions based on the microlensing approximation and analytical toy models of the emission geometry. A realistic concern with incorporating a physical disk was that the CBD might obscure our view of the SLF, considering they only appreciably occur for a near edge-on line of sight. However, this work shows that the CBD is in fact more a friend than foe in the detection, because while the CBD does indeed block other sources of emission that constitute noise, the bent trajectories of the light from the lensed minidisks remain visible even for these edge-on configurations.

Most thin-walled metallic structural members experience some extent of interactive buckling that corrodes the load carrying capacity. Current design methods predict the strength of thin-walled metallic structural members based on individual buckling limit-states and limited case of interactive buckling limit state. In order to develop design methods for most coupled buckling limit states, the interaction of buckling modes needs to be studied. This dissertation first introduces a generally applicable methodology for Generalized Beam Theory (GBT) elastic buckling analysis on members with holes, where the buckling modes of gross cross-section interact with those of net cross-section. The approach treats member with holes as a structural system consisting of prismatic sub-members. These sub-members are connected by enforcing nodal compatibility conditions for the GBT discretization points at the interfaces. To represent the shear lag effect and nonlinear normal stress distribution in the vicinity of a hole, GBT shear modes with nonlinear warping are included. Modifications are made to the GBT geometric stiffness because of the influence from shear lag effect caused by holes. In the following sections, the GBT formulation for a prismatic bar is reviewed and the GBT formulation for members with holes is introduced. Special aspects of analyzing members with holes are defined, namely the compatibility conditions to connect sub-members and the geometric stiffness for members with holes. Validation and three examples are provided. The second topic of this dissertation involves a buckling mode decomposition method of normalized displacement field, bending stresses and strain energy for thin-walled member displacement field (point clouds or finite element results) based on generalized beam theory (GBT). The method provides quantitative modal participation information regarding eigen-buckling displacement fields, stress components and elastic strain energy, that can be used to inform future design approaches. In the method, GBT modal amplitudes are retrieved at discrete cross-sections, and the modal amplitude field is reconstructed assuming it can be piece-wisely approximated by polynomials. The unit displacement field, stress components and strain energy are all retrieved by using reconstructed GBT modal amplitude field and GBT constitutive laws. Theory and examples are provided, and potential applications are discussed including cold-formed steel member design and post-disaster evaluation of thin-walled structural members. In the third part, post-buckling modal decomposition is made possible by development of a geometrically nonlinear GBT software. This tool can be used to assist understanding couple-buckling limit-states. Lastly, the load-deformation response considering any one GBT mode is derived analytically for fast computation and interpretation of structural post-buckling behavior. / Ph. D. / Here I present novel analytical methods to quantitatively decompose interactive buckling in the thin-walled structures. Interactive buckling, where multiple buckling modes are present to initiate structure failure, often controls the load-carrying capacity of thin-walled structures, e.g., the amount of load a column can withstand or the maximum acceleration a space shuttle can experience. In this research, based on Generalized Beam Theory, I describe in detail the analytical methods revealing how buckling modes are coupled and contribute to key quantities related to the structural failure, namely, displacement, stress, and strain energy. I obtain the algorithms by performing rigorous mathematical derivations based on thin-walled mechanics. The research not only facilitates better building design according to the simplified method in the current design standard, but also enables advanced, nonlinear modal decomposition analysis using the custom-made Finite Element program. These studies aim to provide the quantitative understanding of the coupled buckling mechanism and further the development of more powerful strength prediction methods for thin-walled structures.

Due to the high extinction along the plane of the Milky Way towards the Galactic Center (GC), it is useful to look at objects that are bright in the near-infrared (near-IR) to obtain data with Earth-based instruments. To identify X-ray Binary (XRB) counterparts towards the GC, we used near-IR spectra from the Large Binocular Telescope (LBT). After reducing the LUCI/LBT spectra with the superFATBOY (sFB) pipeline, we compared our near-IR spectra to previously matched IR and X-ray sources in the GC (DeWitt, 2011). Particularly, we looked for H and He emission lines, which indicate signs of a hard radiation field present with typically red giant or red supergiant stars in the GC. This illustrates a likely physical association between the X-ray source and its IR counterpart.

Approved for public release, distribution is unlimited / Resonant excitation tests of rotor blades in vacuum spin pits using discrete oil jets showed that impact erosion of the blades could limit test times, but lower excitation amplitudes were produced using mist nozzles. Smaller diameter discrete jets might extend test times, but to fully prevent erosion, oil mist droplet size needed to be 30 microns or less. The present study examined both approaches. Prototype nozzles were developed to create 0.005 inch diameter multiple discrete jets using first alumina, then stainless steel tubing, laser and micro-machine drilling. The latter technique was selected and 50 were manufactured for evaluation in HCF spin tests. A vacuum test chamber was built to observe and photograph spray patterns from the prototype nozzles and from commercially available mist nozzles. An LDV system was used successfully to determine the velocity of the oil droplets within the mist. A complete mapping of mist nozzle sprays is required to allow routine design of blade excitation systems. / Lieutenant, United States Navy

A presente dissertação tem como objeto de estudo sistemas da física da matéria condensada que sejam capazes de simular sistemas gravitacionais, tais como buracos negros e universos em expansão, onde processos quânticos tomam parte. Neste estudo nos debruçamos principalmente sobre o modelo do fluido e condensados de Bose-Einstein. No modelo do fluido exploramos a geometria efetiva que surge e os problemas de back-reaction e dos modos trans-planckianos de campos quânticos. No modelo baseado em condensados exploramos sua faceta cosmológica e a possibilidade de campos maciços. Além destes dois modelos de grande relevância na literatura, ainda expomos os análogos em cordas elásticas e os baseados em ondas na superfícies de fluidos e uma análise geral baseada no formalismo lagrangeano para campos. / This dissertation has as object of study systems of condensate-matter physics which can simulate gravitational systems like black holes and expanding universes where quantum processes take place. In this study we lay attention mainly on the fluid model and on Bose-Einstein-condensate-based models. In the fluid model we explore the features of the emergent geometry and other problems like the back-reaction and the trans-planckian modes of quantum fields. In the condensate-based models we explore their cosmological aspects and the possibility for massive fields. Moreover, we shall present two other models, the elastic string and the surface-wave-based models in fluids, and a very general analysis based on the Lagrangean formalism for fields.

<p>String theory is a unified framework for general relativity and quantum mechanics, thus being a theory of quantum gravity. In this thesis we discuss various aspects of quantum gravity for particular systems, having in common the existence of horizons. The main motivation is that one major challenge in theoretical physics today is in trying to understanding how time dependent backgrounds, with its resulting horizons and space-like singularities, should be described in a controlled way. One such system of particular importance is our own universe.</p><p>We begin by discussing the information puzzle in de Sitter space and consequences thereof. A typical time-scale is encountered, which we interpreted as setting the thermalization time for the system. Then the question of closed time-like curves is discussed in the combined setting where we have a rotating black hole in a Gödel-like universe. This gives a unified picture of what previously was considered as independent systems. The last three projects concerns $c=1$ matrix models and their applications. First in relation to the RR-charged two dimensional type 0A black hole. We calculate the ground state energy on both sides of the duality and find a perfect agreement. Finally, we relate the 0A model at self-dual radius to the topological string on the conifold. We find that an intriguing factorization of the theory previously observed for the topological string is also present in the 0A matrix model.</p>

String theory is a unified framework for general relativity and quantum mechanics, thus being a theory of quantum gravity. In this thesis we discuss various aspects of quantum gravity for particular systems, having in common the existence of horizons. The main motivation is that one major challenge in theoretical physics today is in trying to understanding how time dependent backgrounds, with its resulting horizons and space-like singularities, should be described in a controlled way. One such system of particular importance is our own universe. We begin by discussing the information puzzle in de Sitter space and consequences thereof. A typical time-scale is encountered, which we interpreted as setting the thermalization time for the system. Then the question of closed time-like curves is discussed in the combined setting where we have a rotating black hole in a Gödel-like universe. This gives a unified picture of what previously was considered as independent systems. The last three projects concerns $c=1$ matrix models and their applications. First in relation to the RR-charged two dimensional type 0A black hole. We calculate the ground state energy on both sides of the duality and find a perfect agreement. Finally, we relate the 0A model at self-dual radius to the topological string on the conifold. We find that an intriguing factorization of the theory previously observed for the topological string is also present in the 0A matrix model.

A presente dissertação tem como objeto de estudo sistemas da física da matéria condensada que sejam capazes de simular sistemas gravitacionais, tais como buracos negros e universos em expansão, onde processos quânticos tomam parte. Neste estudo nos debruçamos principalmente sobre o modelo do fluido e condensados de Bose-Einstein. No modelo do fluido exploramos a geometria efetiva que surge e os problemas de back-reaction e dos modos trans-planckianos de campos quânticos. No modelo baseado em condensados exploramos sua faceta cosmológica e a possibilidade de campos maciços. Além destes dois modelos de grande relevância na literatura, ainda expomos os análogos em cordas elásticas e os baseados em ondas na superfícies de fluidos e uma análise geral baseada no formalismo lagrangeano para campos. / This dissertation has as object of study systems of condensate-matter physics which can simulate gravitational systems like black holes and expanding universes where quantum processes take place. In this study we lay attention mainly on the fluid model and on Bose-Einstein-condensate-based models. In the fluid model we explore the features of the emergent geometry and other problems like the back-reaction and the trans-planckian modes of quantum fields. In the condensate-based models we explore their cosmological aspects and the possibility for massive fields. Moreover, we shall present two other models, the elastic string and the surface-wave-based models in fluids, and a very general analysis based on the Lagrangean formalism for fields.

This thesis is divided in two parts: the first part is dedicated to the study of black hole solutions in a theory of modified gravity, called massive gravity, that may be able to explain the actual stage of accelerated expansion of the Universe, while in the second part we focus on constraining primordial black holes as dark matter candidates.<p><p>In particular, during the first part we study the thermodynamical properties of specific black hole solutions in massive gravity. We conclude that such black hole solutions do not follow the second and third of law of thermodynamics, which may signal a problem in the model. For instance, a naked singularity may be created as a result of the evolution of a singularity-free state.<p><p>In the second part, we constrain primordial black holes as dark matter candidates. To do that, we consider the effect of primordial black holes when they interact with compact objects, such as neutron stars and white dwarfs. The idea is as follows: if a primordial black hole is captured by a compact object, then the accretion of the neutron star or white dwarf’s material into the hole is so fast that the black hole destroys the star in a very short time. Therefore, observations of long-lived compact objects impose constraints on the fraction of primordial black holes. Considering both direct capture and capture through star formation of primordial black holes by compact objects, we are able to rule out primordial black holes as the main component of dark matter under certain assumptions that are discussed.<p><p>To better understand the relevance of these subjects in modern cosmology, we begin the thesis by introducing the standard model of cosmology and its problems. We give particular emphasis to modifications of gravity, such as massive gravity, and black holes in our discussion of the dark sector of the Universe./<p>Cette thèse est divisée en deux parties :la première partie est consacrée à l’étude de certaines solutions de trous noirs dans une théorie modifiée de la gravité, appelée la gravité massive, qui peut être en mesure d’expliquer l’expansion accélérée de l’Univers; tandis que dans la seconde partie, nous nous concentrons sur des contraintes sur les trous noirs primordiaux comme candidats de matière noire.<p><p>En particulier, au cours de la première partie, nous étudions les propriétés thermodynamiques de solutions spécifiques de trous noirs en gravité massive. Nous en concluons que ces solutions de trous noirs ne suivent ni la deuxième, ni la troisième loi de la thermodynamique, ce qui semble indiquer une inconsistance dans le modèle. Par exemple, une singularité nue peut être créée à la suite de l’évolution d’un état sans aucune singularité.<p><p>Dans la deuxième partie, nous mettons des contraintes sur les trous noirs primordiaux en tant que candidats de matière noire. Pour ce faire, nous considérons l’effet des trous noirs primordiaux lorsqu’ils interagissent avec des objets compacts, tels que les étoiles à neutrons et les naines blanches. L’idée est comme suit :si un trou noir primordial est capturé par un objet compact, alors l’accrétion du matériel constituant l’étoile à neutrons ou la naine blanche est si rapide que le trou noir détruit l’étoile en un temps très court. Par conséquent, les observations d’objets compacts imposent des contraintes sur la fraction de trous noirs primordiaux. Considérant à la fois la capture directe des trous noirs primordiaux par les objets compacts et la capture au travers de la formation stellaire, nous sommes en mesure d’exclure les trous noirs primordiaux comme la composante principale de matière noire sous certaines hypothèses qui sont discutées.<p><p>Pour mieux comprendre la pertinence de ces sujets dans la cosmologie moderne, nous commençons la thèse par l’introduction du modèle standard de la cosmologie et de ses problèmes. Nous donnons une importance particulière aux modifications de la gravité, telles que la gravité massive, et aux trous noirs dans notre discussion sur le secteur sombre de l’Univers. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished