In this thesis we investigate the quantum aspects of black holes near extremality. In particular we seek evidence that a near-extremal black hole has a microscopic description in terms of a two dimensional conformal field theory (CFT). We first demonstrate how the low temperature expansion of the first law of thermodynamics leads to an expression for the entropy of extremal black holes which can be recast as the Cardy formula for the entropy of a chiral two dimensional CFT, in agreement with the Extremal Black Hole/CFT correspondence. We apply Sen’s entropy function formalism to fortify this result by reproducing it in a gravitational setup. We extend our first law analysis to a class of near-Extremal Vanishing Horizon (near-EVH) black holes. These black holes have low entropy and temperature, and their geometries contain locally asymptotically AdS3 throats in the near horizon region. The low temperature expansion of the first law is compatible with the first law for a three dimensional BTZ black hole. As the BTZ black hole has an AdS/CFT description in terms of a non-chiral two dimensional CFT, our result can be viewed as thermodynamic evidence for the EVH/CFT correspondence, which states that gravity on the near horizon EVH geometry is described by a 2d CFT. A near-EVH black hole, or low energy excitation around an EVH black hole, is described by excitations of the dual 2d CFT. As case studies of our first law analysis and the EVH/CFT correspondence, we focus on two asymptotically AdS5× S5 classes of near-EVH black holes. The two cases have interesting individual properties and, by the AdS/CFT correspondence, dual descriptions as states in N = 4 super Yang-Mills theory . We can compare these (UV) pictures to the two dimensional descriptions that emerge from the near horizon, or low energy, dynamics. All EVH near horizon geometries have local AdS3 factors which become BTZ black holes when the configurations are excited from EVH to near-EVH. In the study of static black holes with three R-charges, we examine the non-BPS and near- BPS regimes separately. While the non-BPS near horizon limit is locally regular, in the near- BPS case the near horizon procedure requires focussing geometrically on a strip of the horizon, and the degrees of freedom of the dual CFT2 can be associated with stretched strings between giant gravitons in the transverse five-sphere. The near-EVH limit of non-BPS stationary charged black holes is obtained by taking the vanishing limit of one or both of the angular momenta. When one of the momenta is small, the AdS3 angle is a combination of azimuthal angles in the AdS5 and S5 regions of the geometry. Taking the vanishing limit of both of the angular momenta leads to a near horizon limit which contains a BTZ black hole that is non-trivially fibred by a three-sphere. For each of the case studies we use the AdS3/CFT2 dictionary to specify dual IR CFT2 descriptions of the black holes. We outline a map between the UV and IR near-EVH excitations and demonstrate how the first law reduces in the near-EVH limit to the first law of a BTZ black hole. As a consistency check we compare our results with those of the Kerr/CFT correspondence.

China has become an increasingly important economic, and more recently, political force in the Middle East. Coupled with the perceived reduction in American power, this has caused Middle East states closely tied to the US to hedge in response to increased strategic ambiguity. Their strategies are characterized by simultaneous attempts to capture the economic and political gains of cooperation with China, while minimizing the risk of a continued dependence for their security on a US perceived to be disengaging from the region. This has resulted in a self-reinforcing regional dynamic of ambiguity that has incentivized these states to draw closer to China and thereby increase Chinese influence in the region. To test this theory, this paper examines the case of Saudi Arabia before discussing the effects of this strategy on the region’s dynamics. Hedging can create a self- fulfilling prophecy that reduces the power of the established hegemon, increases the power of a rising state, and increases the probability of a new systemic structure emerging.

Diabetes Mellitus is a major health problem which affects about 200 million people worldwide. Diabetics require their blood glucose levels to be kept within the normal range in order to prevent diabetes-related complications from occurring. Blood glucose measurement is therefore of vital importance. The current glucose measurement techniques are, however, painful, inconvenient and episodic. This document provides an investigation into the use of near-infrared spectroscopy for continuous, non-invasive measurement of blood glucose. Artificial neural networks are used for the development of multivariate calibration models which predict glucose concentrations based on the near-infrared spectral data. Simulations have been performed which make use of simulated spectral data generated from the characteristic spectra of many of the major components of human blood. The simulations show that artificial neural networks are capable of predicting the glucose concentrations of complex aqueous solutions with clinically relevant accuracy. The effect of interference, such as temperature changes, pathlength variations, measurement noise and absorption due other analytes, has been investigated and modelled. The artificial neural network calibration models are capable of providing acceptably accurate predictions in the presence of multiple forms of interference. It was found that the performance of the measurement technique can be improved through careful selection of the optical pathlength and wavelength range for the spectroscopic measurements, and by using preprocessing techniques to reduce the effect of interference. Although the simulations suggest that near-infrared spectroscopy is a promising method of blood glucose measurement, which could greatly improve the quality of life of diabetics, many further issues must be resolved before the long-term goal of developing a continuous non-invasive home glucose monitor can be achieved.

A madeira é uma excelente matéria-prima renovável, sendo empregada como fonte de celulose e na construção civil, e sendo usada ainda como combustível. Contudo, as propriedades da madeira variam muito entre as espécies. Logo, saber a qual espécie pertence a madeira, assim como algumas de suas propriedades é essencial para um planejamento adequado de sua aplicação, evitando desperdícios e melhorando a qualidade dos produtos derivados do material. No presente estudo, analisou-se a aplicação da espectroscopia de infravermelho-próximo (NIR) na identificação e predição de propriedades físicas de madeiras nativas ou plantadas no Brasil, as quais apresentam grande variação entre suas propriedades e características anatômicas. Primeiramente, foi verificada a relação do espectro NIR com a densidade básica e algumas das características anatômicas importantes para identificação de madeiras, em especial aquelas ligadas aos raios parênquimáticos. Em seguida, com a espectroscopia NIR, foram desenvolvidos modelos para predição da densidade básica em madeiras de várias espécies brasileiras. Por fim, aplicou-se a espectroscopia NIR para discriminação entre as madeiras de Dalbergia nigra e D. spruceana, as quais são muito semelhantes em aspecto e características anatômicas. Os resultados sugerem que a espectroscopia de infravermelho-próximo é uma potencial ferramenta para classificação das diferentes madeiras brasileiras de acordo com suas propriedades físicas. Os resultados sugerem ainda uma metodologia auxiliar no processo de identificação pela anatomia do lenho. / Wood is an excellent renewable raw material, used as fuel, pulp and as building material. However, the properties of wood vary widely among species. Therefore, knowing the wood species as well as some of its properties is essential for proper planning of its application, avoiding waste and improving the quality of wood based products. In this study it was analysed the application of the near infrared spectroscopy (NIR) to identification and prediction of physical properties of native or planted timbers from Brazil, which show great variation on their properties and anatomical features. First, it was verified the relationship between the NIR spectrum and the basic density as well as some important anatomical features for wood identification, especially those related to ray parenchyma. Then, using NIR spectroscopy, models were developed to predict the wood basic density from various Brazilian species. It was also applied NIR spectroscopy to separate the woods from Dalbergia nigra and D. spruceana, two woods that are very similar in appearance and anatomical features. The results suggest that near-infrared spectroscopy is a potential tool for classification of various Brazilian woods based on their physical properties, as well as an auxiliary method in wood anatomy identification.

Yeung Shun-hin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 52-54). / Abstracts in English and Chinese. / TITLE PAGE --- p.i / THESIS COMMITTEE --- p.ii / ABSTRACT (ENGLISH) --- p.iii / ABSTRACT (CHINESE) --- p.iv / ACKNOWLEDGEMENTS --- p.v / TABLES OF CONTENTS --- p.vi / LIST OF FIGURES --- p.viii / LIST OF TABLES --- p.x / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Computer-controlled Data Acquisition and Frequency Calibration System for a Ti: sapphire laser spectrometer --- p.3 / Chapter Section 2A --- Motivation and Overview --- p.3 / Chapter Section 2B --- The Hardware --- p.5 / Chapter Section 2C --- The Program --- p.12 / Chapter Section 2D --- Summary --- p.27 / Chapter Chapter 3 --- Cavity Enhanced Absorption Spectroscopy Using Phase-Sensitive Detection --- p.28 / Chapter Section 3A --- Motivation --- p.28 / Chapter Section 3B --- Cavity ring-down technique: the background --- p.29 / Chapter Section 3C --- Cavity enhanced absorption spectroscopy: a historical review --- p.34 / Chapter Section 3D --- Experimental Apparatus --- p.37 / Chapter Section 3E --- Results of Performance tests --- p.41 / Chapter Section 3F --- Applications --- p.45 / Chapter Section 3G --- Summary --- p.49 / Chapter Chapter 4 --- Concluding Remarks --- p.50 / REFERENCES --- p.52

Working with nanoscale optics requires methods and equipment designed for the purpose. This thesis describes the development of techniques and a system for performing highly localised spectroscopy. The system consists of a nanonics multiview 2000 scanning near-field optical microscope, a grating spectrometer and a photonic crystal fibre supercontinuum light source. Discussion of the microscope includes its modes of operation and development of software to collect and analyse data. In order to demonstrate the setup, an example of localised spectroscopy is presented in the form of an investigation of hollow core photonic crystal fibre. Taking spectra of the components of the cladding of these fibres makes it possible to investigate the origins of bandgap guidance. A core focus of nanoscale optics is the interaction of light with metal structures. This field is called plasmonics. Fabrication of structures is presented and requires special facilities and processes. These processes are both time consuming and expensive, both factors that emphasise the need for prior modelling. Forward difference time domain modelling of a proposed structure comprising of a concentrically arranged ring and disk is explored using home written code and a commercial package called CST Microwave Studio. The investigation of this concentric design through modelling shows a very highly localised field enhancement which can be engineered to have a narrow spectral resonance in the near infrared. The interaction of the two components which govern this resonance is explained using a theory called plasmon hybridization. Once the optical behaviour of small metal objects is understood they can be used in other ways. An example of this is shown in Porous Silicon. As a material it provides an excellent template for formation of metal nano-particles. Embedded in a high surface area network of silicon these particles can be used as very effcient catalysts.

Estimating the dense image motion or optical flow on a real-world nonrigid surface is a fundamental research issue in computer vision, and is applicable to a wide range of fields, including medical imaging, computer animation and robotics. However, nonrigid surface tracking is a difficult challenge because complex nonrigid deformation, accompanied by image blur and natural noise, may lead to severe intensity changes to pixels through an image sequence. This violates the basic intensity constancy assumption of most visual tracking methods. In this thesis, we show that local geometric constraints and long term feature matching techniques can improve local motion preservation, and reduce error accumulation in optical flow estimation. We also demonstrate that combining RGB data with additional information from other sensing channels, can improve tracking performance in blurry scenes as well as allow us to create nonrigid ground truth from real world scenes. First, we introduce a local motion constraint based on a laplacian mesh representation of nonrigid surfaces. This additional constraint term encourages local smoothness whilst simultaneously preserving nonrigid deformation. The results show that our method outperforms most global constraint based models on several popular benchmarks. Second, we observe that the inter-frame blur in general video sequences is near linear, and can be roughly represented by 3D camera motion. To recover dense correspondences from a blurred scene, we therefore design a mechanical device to track camera motion and formulate this as a directional constraint into the optical flow framework. This improves optical flow in blurred scenes. Third, inspired by recent developments in long term feature matching, we introduce an optimisation framework for dense long term tracking -- applicable to any existing optical flow method -- using anchor patches. Finally, we observe that traditional nonrigid surface analysis suffers from a lack of suitable ground truth datasets given real-world noise and long image sequences. To address this, we construct a new ground truth by simultaneously capturing both normal RGB and near-infrared images. The latter spectrum contains dense markers, visible only in the infrared, and represents ground truth positions. Our benchmark contains many real-world scenes and properties absent in existing ground truth datasets.

The impact of buoyancy on the development of starting flows in the near field was experimentally investigated using the Digital Particle Image Velocimetry and Planar Laser Induced Flourescence techniques. The experiments were conducted by releasing cylindri-cal columns of fluid into a glass water tank. Two diameters (0.95 and 1.9 cm) and four aspect ratios, ranging from 2 to 8, were examined. The fluid was released by bursting the thin latex membrane that held it in the tube. The buoyant fluid had a density difference of 4.7%. The flow was imaged at 60 Hz up to 7 diameters downstream. For the aspect ratio of 2, the flow developed into a single buoyant vortex ring (BVR), and was compared to a purely momentum driven vortex ring (MVR) generated with the same setup. For the aspect ratios of 4, 6, and 8, the flow was similar to a starting plume, with a vortical cap, followed by a columnar tail. The BVR's diameter grew linearly in space, with a full spreading angle of 18 degrees, while the MVR's diameter remained constant. The BVR started out as an axis touching ring, and transitioned to non-axis touching, opposite of the behavior of the MVR. The total circulation for the BVR was more than twice the amount predicted by the slug flow model, and the impulse grew linearly in time. The impulse of the MVR decayed slightly after the intial growth. The flows began to transition to thermal behavior at down-stream distance proportional to the cube root of the initial fluid volume. For all aspect ratios the impulse grew linearly in time. The growth rate was roportional to the initial buoyant force. The circulation generated by the addition of buoyancy was proportional to the square root of the initial buoyant force. Also the addition of buoyancy suppressed the separation of a starting vortex.

This thesis describes the search for neutrino-production of single photons using the off-axis near detector at 280 metres (ND280) of the T2K experiment. A photon selection is used to perform the searches using the first Fine Grained Detector (FGD1) of the ND280. The thesis also highlights the importance of systematic uncertainties in the analysis, since the selection is background dominated. After careful characterisation of the systematic uncertainties and estimation of the efficiency, it is concluded that, with the selected 39 data events and the expected background of 45 events, the limit for neutrino-induced single photons, at T2K energies, is 0:0903 x 10-38cm2/nucleon. This result can be compared with the expected limit of 0:1068 x 10-38cm2/nucleon. Using ND280's neutrino energy distribution (peaked at 600 MeV), NEUT predicts a flux-averaged cross section of 0:000239 x 10-38cm2/nucleon. A fit to the muon and electron (anti-) neutrinos selections in the ND280 was performed. The aim of this analysis is to use a data-driven method to constrain the electron (anti-) neutrinos background events at SK, the far detector and electron neutrino cross section parameters for oscillation analyses. These are fundamental inputs in the context of the searches for Charge-Parity (CP) violation in the neutrino sector. After a fit to the nominal Monte Carlo was realised, the electron neutrino and anti-neutrino cross section normalisation uncertainties are found to be 7.6% and 19.3%, repectively. Although these numbers are much higher than the assumed 3% uncertainty of all the CP violation searches performed at T2K up to now, the difference in the δCP log-likelihood is found to be acceptable as the one sigma contours are not very different and the exclusion of the δCP = 0 is roughly the same.

Book Summary: This work is the fourth Small Wars Journal anthology focusing on radical Sunni Islamic terrorists and insurgent groups. It covers this professional journals writings for 2016 and is a compliment to the earlier Global Radical Islamist Insurgency anthologies that were produced as Vol. I: 2007-2011 (published in 2015) and Vol. II: 2012-2014 (published in 2016) and Jihadi Terrorism, Insurgency, and the Islamic State spanning 2015 (published in 2017). This anthology, which offers well over 900 pages of focused analysis, follows the same general conceptual breakdown as the earlier works and is divided into two major thematic sectionsone focusing on Al Qaeda and Islamic state activities in 2016 and the other focusing on US-Allied policies and counterinsurgent strategies.