One of the most important predictions of General Relativity, Einstein’s theory of gravity, is the existence of gravitational radiation. The strongest source of such radiation is expected to come from the merging of black holes. Upgrades to large ground based interferometric detectors (LIGO, VIRGO, GEO 600) have increased their sensitivity to the point that the first direct observation of a gravitational wave is expected to occur within the next few years. The chance of detection is greatly improved by the use of simulated waveforms which can be used as templates for signal processing. Recent advances in numerical relativity have allowed for long stable evolution of black hole mergers and the generation of expected waveforms. openGR is a modular, open framework black hole evolution code developed at The University of Texas at Austin Center for Relativity. Based on the BSSN (strongly hyperbolic) formulation of Einstein’s equations and the moving puncture method, we are able to model the evolution of a binary black hole system through the merger and extract the gravitational radiation produced. Although we are generally interested in binary interactions, openGR is capable of handling any number of black holes. This work serves as an overview of the capabilities of openGR and a demonstration of the physics it can be used to explore. / text

Drilling is a standard process for producing holes in metal materials. With an increased hole depth the demands increase on both machine and tool. Deep hole drilling is a complex process which ischaracterized by a high metal removal rate and hole accuracy. A hole deeper than ten times the diameter can be considered a deep hole which requires a specialized drilling technique. During adeep hole drilling process, the forces generated on the deep hole drill give a rise to a resultant radial force. The resultant radial force pushes the drill in a radial direction during a drilling operation. The radial force direction is of crucial importance in regard of tool guidance, stability and hole size accuracy. This force affects tool performance, reduces tool life and has an impact on the bore surface. Due to the complex nature of deep hole drilling, Sandvik Coromant wishes to get a better understanding of how their current deep hole drilling tools are balanced. The purpose of this study is to conduct a survey of a number of drills of Sandvik Coromant deep hole drill assortment. The main aim of this study is to calculate and measure the resultant radial force generated during a deep hole drilling operation. The forces are calculated with the aid of a calculation program and test-runs on a number of drills. This report presents the calculated magnitude and direction of the resultant radial force duringentrance, full intersection and at the exit of the workpiece. In addition to the measured values of theresultant radial force during entry and full intersection. Four different drill geometries are evaluated which of two are competitor drills. A deep hole drill geometry is re-modified in aspect to drill stability based on the outcome of the measured and calculated results. The results acquired from the performed calculation and measurements of the resultant showed that the resultant radial force acts in an angular direction that was outside the range between the support pads. This true for three of the four evaluated drill geometries. There were minor differences between the measured and calculated forces which enforce the reliability of the used calculation program. The modified drill geometry of a deep hole drill gave an indication of which geometry variables have impact on the resultant radial force magnitude and angular direction. The data presented in this report can be a base for future development of a deep hole drill toolgeometry in regard to the resultant radial force. Variables affecting the calculated results and theresultant radial force are presented and discussed. The study is concluded with suggestions of futurework based on the acquired data.

This thesis deals with the problems of exploration and map construction of a dangerous network by mobile agents, and it introduces new general mechanisms for inter-agent communication, which could be applied to other mobile agents' problems. A dangerous network contains a harmful process called Black Hole that destroys all agents entering the node where it resides, without leaving any observable trace. The task for the agents, which are moving asynchronously, is to construct a map of the network with edges incident on the black hole unambiguously identified. Two types of communication mechanisms are considered: whiteboards and tokens. In the whiteboard model every node provides a shared memory on which agents can read and write. When communication occurs through tokens, instead, the agents have some pebbles that can be placed on and picked up from the nodes. Four different costs for comparing the efficiency of the protocols are taken into account: the number of agents required, the number of moves performed, the size of the whiteboard (or the token capacity at a node), and time. The black hole search problem is considered first in ring networks with whiteboards, and optimal exact time and move complexities are established improving all existing results. The same problem is then studied in arbitrary unknown graphs and it is solved in the token model by using a constant number of tokens in total. The protocol improves on existing results and is based on a novel technique for communicating using tokens. Finally, the new method of communicating using tokens described in the context of black hole search is generalized to propose a novel communication mechanism among the agents that could possibly be employed for any distributed algorithm by mobile agents.

A standard procedure for P3HT:PCBM bulk-heterojunction solar cells has been developed. Fabrication conditions, such as environment; solution concentration, thickness of active layer or post-treatment methods are systematically optimized. The best device performance is obtained by slow-drying spin-coated P3HT:PCBM (1:0.8) blend layer with DCB as solvent. C60:LiF composite films with up to 80% LiF concentration as hole blocking layer have been developed to significantly increase power conversion efficiencies of OPV devices. The short-circuit current density is greatly enhanced, without sacrificing open-circuit voltage and fill factor. Due to its superior oxygen diffusion blocking effect, the C60:LiF composite layer also can provide a more effective passivation film than a thin LiF layer, resulting in an impressive enhancement in air stability of devices.

A standard procedure for P3HT:PCBM bulk-heterojunction solar cells has been developed. Fabrication conditions, such as environment; solution concentration, thickness of active layer or post-treatment methods are systematically optimized. The best device performance is obtained by slow-drying spin-coated P3HT:PCBM (1:0.8) blend layer with DCB as solvent. C60:LiF composite films with up to 80% LiF concentration as hole blocking layer have been developed to significantly increase power conversion efficiencies of OPV devices. The short-circuit current density is greatly enhanced, without sacrificing open-circuit voltage and fill factor. Due to its superior oxygen diffusion blocking effect, the C60:LiF composite layer also can provide a more effective passivation film than a thin LiF layer, resulting in an impressive enhancement in air stability of devices.

Thesis (M.A.)--University of Wisconsin--Madison, 1963. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 75-76.

The project concerns the study of the interplay among quantum mechanics, statistical mechanics and thermodynamics, in isolated quantum systems. The goal of this research is to improve our understanding of the concept of thermal equilibrium in quantum systems. First, I investigated the role played by observables and measurements in the emergence of thermal behaviour. This led to a new notion of thermal equilibrium which is specific for a given observable, rather than for the whole state of the system. The equilibrium picture that emerges is a generalization of statistical mechanics in which we are not interested in the state of the system but only in the outcome of the measurement process. I investigated how this picture relates to one of the most promising approaches for the emergence of thermal behaviour in quantum systems: the Eigenstate Thermalization Hypothesis. Then, I applied the results to study the equilibrium properties of peculiar quantum systems, which are known to escape thermalization: the many-body localised systems. Despite the localization phenomenon, which prevents thermalization of subsystems, I was able to show that we can still use the predictions of statistical mechanics to describe the equilibrium of some observables. Moreover, the intuition developed in the process led me to propose an experimentally accessible way to unravel the interacting nature of many-body localised systems. Then, I exploited the "Concentration of Measure" and the related "Typicality Arguments" to study the macroscopic properties of the basis states in a tentative theory of quantum gravity: Loop Quantum Gravity. These techniques were previously used to explain why the thermal behaviour in quantum systems is such an ubiquitous phenomenon at the macroscopic scale. I focused on the local properties, their thermodynamic behaviour and interplay with the semiclassical limit. The ultimate goal of this line of research is to give a quantum description of a black hole which is consistent with the expected semiclassical behaviour. This was motivated by the necessity to understand, from a quantum gravity perspective, how and why an horizon exhibits thermal properties.

Doctor of Philosophy / Chemistry / Ryszard J. Jankowiak / The structure-function relationships of natural pigment–protein complexes are of great interest, as the electronic properties of the pigments are tuned by the protein environment to achieve high quantum yields and photon utilization. Determination of electronic structure and exciton dynamics in protein complexes is complicated by static disorder and uncertainties in the properties of system-bath coupling. The latter is described by the phonon profile (or spectral density), whose shape can only be reliably measured experimentally for the lowest energy state. Low-temperature, laser-based spectroscopies are applied towards model pigment–protein complexes, i.e., the Fenna-Matthews-Olson (FMO) and water-soluble chlorophyll-binding (WSCP) complexes, in order to study system-bath coupling and energy transfer pathways. Site-selective techniques, e.g., hole burning (HB) and fluorescence line narrowing, are utilized to overcome static disorder and reveal details on homogeneous broadening. In addition, excitonic calculations with non-Markovian lineshapes provide information on electronic structure and exciton dynamics. A new lognormal functional form of the spectral density is recommended which appropriately defines electron-phonon parameters, i.e., Huang-Rhys factor and reorganization energy. Absorbance and fluorescence spectral shifts and HB spectra reveal that samples of FMO may contain a subpopulation of destabilized proteins with modified HB efficiencies. Simulations of spectra corresponding to intact proteins indicate that the entire trimer has to be taken into account in order to properly describe fluorescence and HB spectra. The redshifted fluorescence spectrum of WSCP is described by uncorrelated energy transfer as opposed to previous models of excited state protein relaxation. Also, based on nonconservative HB spectra measured for WSCP, a mechanism of electron transfer between chlorophylls and aromatic amino acids is proposed.

abstract: This thesis explores the different aspects of higher curvature gravity. The "membrane paradigm" of black holes in Einstein gravity is extended to black holes in f(R) gravity and it is shown that the higher curvature effects of f(R) gravity causes the membrane fluid to become non-Newtonian. Next a modification of the null energy condition in gravity is provided. The purpose of the null energy condition is to filter out ill-behaved theories containing ghosts. Conformal transformations, which are simple redefinitions of the spacetime, introduces serious violations of the null energy condition. This violation is shown to be spurious and a prescription for obtaining a modified null energy condition, based on the universality of the second law of thermodynamics, is provided. The thermodynamic properties of the black holes are further explored using merger of extremal black holes whose horizon entropy has topological contributions coming from the higher curvature Gauss-Bonnet term. The analysis refutes the prevalent belief in the literature that the second law of black hole thermodynamics is violated in the presence of the Gauss-Bonnet term in four dimensions. Subsequently a specific class of higher derivative scalar field theories called the galileons are obtained from a Kaluza-Klein reduction of Gauss-Bonnet gravity. Galileons are null energy condition violating theories which lead to violations of the second law of thermodynamics of black holes. These higher derivative scalar field theories which are non-minimally coupled to gravity required the development of a generalized method for obtaining the equations of motion. Utilizing this generalized method, it is shown that the inclusion of the Gauss-Bonnet term made the theory of gravity to become higher derivative, which makes it difficult to make any statements about the connection between the violation of the second law of thermodynamics and the galileon fields. / Dissertation/Thesis / Doctoral Dissertation Physics 2014

Essa dissertação consiste de uma revisão dos resultados clássicos sobre a termodinâmica de buracos negros bem como de uma análise crítica das extensões recentes da relação entre a termodinâmica e a dinâmica gravitacional e suas implicações. / This dissertation consists of a revision of the classical results concerning the thermodynamics of black holes as well as a critical analysis of the recent extensions of the relationship between thermodynamics and the gravitational dynamics and its implications.