In this study, the effectiveness of hole-drilling strain gage method on residual stress estimation is investigated. The thermal-elastic-plastic model of commercial Marc finite element method package is employed to simulate and build up the hole-drilling process and residual stress distribute. Two Inconel 690 alloy plate welded with GTAW filling I-52 solder has simulated by using the Marc software first. Then the traditional hole-drilling process is simulated. The simulated residual strain variation data is introduced into the hole-drilling strain-gage method to derive the possible residual stress components. The effects of drilling depth and drill size on the accuracy of estimated residual stress have also been discussed. A comparison between stress components estimated from the traditional hole-drilling strain gage method and simulated from the Marc software was presented. The modified dimensionless parameters are provided by applying the optimum technique. The numerical results indicate that the proposed dimensionless parameters can improve the accuracy of estimated residual stress components significantly.

This dissertation covers two di erent but related topics: the construction of new black hole solutions and the study of the microscopic origin of black hole entropy. In the solution part, two di erent sets of new solutions are found. The rst concerns a Plebanski-Demianski type solution in the ve-dimensional pure Einstein gravity, and the second concerns a three-charge (two of which equal) two-rotation solution to the ve-dimensional maximal supergravity. Obtaining new and interesting black hole solutions is an important and challenging task in studying general relativity and its extensions. During the past decade, the solutions become even more important because they might nd applications in the study of the gauge/gravity duality, which is currently in the central stage of the quantum gravity research. The Kerr/CFT correspondence is a recently propose example of the gauge/gravity duality. In the entropy part, we explicitly show that the Kerr/CFT correspondence can be applied to all known extremal stationary and axisymmetric black holes. We improve over previous works in showing that this can be done in a general fashion, rather than testing di erent solutions case by case. This e ort makes it obvious that the common structure of the near horizon metric for all known extremal stationary and axisymmetric black holes is playing a key role in the success of the Kerr/CFT correspondence. The discussion is made possible by the identi cation of two general ans atze that cover all such known solutions.

It is observed that the flowing bottom-hole temperature (FBHT) changes as a result of production, injection or shutting the well down. Variations in temperature mainly occur due to geothermal gradient, injected fluid temperature, frictional heating and the Joule-Thomson effect. The latter is the change of temperature because of expansion or compression of a fluid in a flow process involving no heat transfer or work. CMG STARS thermal simulation sector model developed in this study was used to analyze FBHT changes and understand the reasons. Twenty three main and five additional cases that were developed by using this model were simulated and relation of BHT with other parameters was investigated. Indeed the response of temperature to the change of some parameters such as bottom-hole pressure and gas-oil ratio was detected and correlation was tried to set between these elements. Observations showed that generally FBHT increases when GOR decreases and/or flowing bottom-hole pressure (FBHP) increases. This information allows estimating daily gas-oil ratios from continuously measured BHT. Results of simulation were compared with a real case and almost the same responses were seen. The increase in temperature after the start of water and gas injection or due to stopping of neighboring production wells indicated interwell communications. Additional cases were run to determine whether there are BHT changes when initial temperature was kept constant throughout the reservoir. Different iteration numbers and refined grids were used during these runs to analyze iteration errors / however no significant changes were observed due to iteration number differences and refined grids. These latter cases showed clearly that variations of temperature don&rsquo / t occur only due to geothermal gradient, but also pressure and saturation changes. On the whole, BHT can be used to get data ranging from daily gas-oil ratios to interwell connection if analyzed correctly.

Abstracts Photoreflectance(PR) of surface-intrinsic n+ type doped GaAs has been measured for various power densities of pumping laser.The spectra exhibited many Franz-Keldysh oscillations,where by the electric field(F) can be determined from the technique of the fast fourier transform.It is known that F's determined from PR are subjected to photovoltaic effect ,but it is difficult to estimate the strength of modulating field in the PR measurements.Hence we have investigated the relation between F and modulating field by using electroreflectance to simulate PR.In this work,the relation will be confirmed by using solely PR.Here a method was devised to obtain the strength of modulating field in the PR measurements.The photo-voltage(Vs)of the pump beam can be measured directly with a lock-in amplifier by making electrical contacts on the front and rear sides of the sample.The strengh of modulation field is equal to Vs/d due to a uniform F in the undoped layer,where d is the thickness of the undoped layer.

In this work¡Awe studied the strain effects on heavy hole (hh) and light hole (lh) bands of Zn1-xMnxSe/GaAs by photoreflectance (PR) spectroscopy . The Zn1-xMnxSe epilayers were grown on GaAs substrates by the MBE technique . There is a biaxial compressive strain exist in the epilayer, due to the different lattice constants between epilayers and substrates .The biaxial strain will shift hh and lh bands and lift the hh-lh degeneracy. In our experiment ,we found that the splitting of the hh and lh transition energies is almost lineally proportional to the Mn ion concentrations. It can be ascribed to the strain in the epilayer . We have also measured the PR of Zn0.96Mn0.04Se/GaAs at various temperatures , and analyzed the transition energy of different temperatures in terms of Varshni relation.

It is known that electroreflectance (ER) of surface-intrinsic-n+ type doped GaAs has exhibited many Franz-Keldysh oscillations to enable the application of fast Fourier transform to separate the heavy and light-hole transitions. However each peak still contains two components, which belong to F+ F/2 and F- F/2 respectively, where F is the built-in field and F is the modulating field of applied voltage (Vac). In this work, we have used a larger Vac to modulate the field, and hence the peaks can be further separated. The peak belonging to heavy hole-transition and F- F/2 can be singled out to compare with Airy function-theory.

Remarkably, an astrophysical black hole has only two attributes: its mass and its spin angular momentum. Spin is often associated with the exotic behavior that black holes manifest such as the production of relativistic and energetic jets. In this thesis, we advance one of the two primary methods of measuring black hole spin, namely, the continuum-fitting method by (1) improving the methodology; (2) testing two foundational assumptions; and (3) measuring the spins of two stellar-mass black holes in X-ray binary systems. Methodology: We present an empirical model of Comptonization that self-consistently generates a hard power-law component by upscattering thermal accretion disk photons as they traverse a hot corona. We show that this model enables reliable measurements of spin for far more X-ray spectral data and for more sources than previously thought possible. Testing the foundations: First, by an exhaustive study of the X-ray spectra of LMC X–3, we show that the inner radius of its accretion disk is constant over decades and unaffected by source variability. Identifying this fixed inner radius with the radius of the innermost stable circular orbit in general relativity, our findings establish a firm foundation for the measurement of black hole spin. Secondly, we test the customary assumption that the inclination angles of the black-hole’s spin axis and the binary’s orbital axis are the same; for XTE J1550–564 we show that they are aligned to within \(12^{\circ}\) by modeling the kinematics of the large-scale jets of this microquasar. Measuring spins: We have made the first accurate continuum-fitting spin measurements of the black hole primaries in H1743–322 and XTE J1550–564. For this latter black hole, we have also measured its spin using the other leading method, namely, modeling the broad red wing of the \(Fe K\alpha\) line. As we show, these two independent measurements of spin are in agreement. / Astronomy

No description available.

This consecutive nonrandomized comparative interventional study was designed to examine the association between pars plana vitrectomy (PPV) with or without internal limiting membrane (ILM) peeling in the treatment of idiopathic macular holes (IMH). The ILM is the innermost layer of the retina. The macula is located within the retina, and is responsible for central vision. Although IMH manifests in a relatively small region within the retina, patients notice significant drops in visual acuity up to the 20/400 - 20/800 level (legally blind in the affected eye). In the literature, the anatomic success rate of macular hole surgery has been reported between 48% - 94%. To best treat idiopathic macular holes, it is imperative that physicians have access to the most up-to-date information regarding the treatment outcomes. This study included 55 eyes of 52 patients who received surgery at the Beth Israel Deaconess Medical Center for idiopathic macular holes between December 1999 and January 2015. Patients were non-randomly assigned to PPV with or without ILM peeling. Early patients did not receive ILM peeling, while more recent patients did. The primary endpoint measured was macular hole (MH) status as established by ocular coherence tomography (OCT) within 6 to 12 months of the vii procedure. 36 out of 39 (92.3%) eyes in the ILM peeling group had closed MH. In the comparison group without ILM peeling, 11 out of 16 (68.8%) eyes had closed MH. In comparison to the conventional PPV without ILM peeling, these findings suggest that PPV with ILM peeling is associated with a significantly higher anatomic success rate (OR, 5.45; [95% CI, 1.12 to 26.55]; P = 0.023). / 2018-06-16T00:00:00Z

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第22251号 / 理博第4565号 / 新制||理||1655(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 嶺重 慎, 准教授 前田 啓一, 教授 長田 哲也 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM