VictorJuiz/thesis huggingface dataset:
Meaning and Purpose: A Study of Spiritual Quest Amongst Stanford Students
Keywords: Graduate School of Education
Stanford University
Spiritual Quest
Spirituality
Meaning
Purpose
Thesis

The college years can be a critical period of self-formation for some students, as they develop their sense of identity, values and independence. For some students, major life events provoke pressing questions of meaning and purpose, which may be interpreted as spiritual questions. Against a backdrop where topics of spirituality and faith are seen as taboo and anti-intellectual, there was a gap in our understanding of how Stanford students engaged in questions of meaning and purpose. This study interviewed 39 students and 4 members of the Stanford faculty and staff with the intention of understanding the process by which students undertook Spiritual Quest, defined and informed by reference to a nation-wide longitudinal study undertaken by Astin, Astin and Lindholm (2011). Student participants also took a short survey that determined their level of Spiritual Quest, using the measure validated by Astin et al. (2011). Generally, the results weakly suggested that this sample of convenience of Stanford students underperformed the national norm established in the 2007 Astin et al. (2011) study for reasons unknown. High Spiritual Quest scores were associated with participants for whom questions of meaning and purpose where highly salient. This study also identified patterns in events that catalyzed questing; these events were largely negative, such as the death of a loved one or major injury. Major Stanford-related factors that supported and obstructed quest included conversations with good friends and a culture of busyness, pressure, stress, and materialism respectively. There was a complex and highly variable relationship between Quest and students’ mental and psychological well- being, adding to the conclusion that individuals undertook Quest in vastly different ways and so needed many flexible points of support. When asked what could be improved at Stanford in order to better facilitate Spiritual Quest, participants suggested more secular spaces and communities where questions of meaning and purpose could be discussed, and better access to existing resources.
The meanings of capitalism [electronic resource] : Chinese bankers in post-1997 Hong Kong
Keywords: Anthropology.

This dissertation aims to understand the meanings of capitalism among Chinese bankers in post-1997 Hong Kong. I found that Chinese bankers of Mainland and Hong Kong backgrounds articulate capitalist meanings in different ways, both in relation to work and everyday life, and to more abstract notions such as the relationships between the government and society. In addition to making these generalizations, this dissertation also portrays the wide spectrum of capitalist meanings that are in circulation among Chinese bankers in Hong Kong. By describing the meanings of capitalism, and also by exploring the cultural and historical specificities of these meanings, this dissertation aims to addressing a gap in scholarly literature: that most studies of capitalism focus on what capitalism is, rather than what it means.
Measurement of in-situ combustion reaction kinetics with high fidelity and consistent reaction upscaling for reservoir simulation [electronic resource]
Keywords: Energy Resources Engineering.

In-situ Combustion is widely accepted as an enhanced oil recovery method that is applicable to various types of oil reservoirs. Prediction of the likelihood of a successful in-situ combustion field project from first principles, however, is unclear. Historically, combustion tube tests of a crude-oil and rock are used to design an in-situ combustion process and to infer whether one expects the process to work at reservoir scale. Ideally, such tests are completed in combination with simulation for prediction and design of combustion recovery processes. Fairly sophisticated reaction models for formation of crude-oil intermediates and their oxidation have been proposed based on kinetics studies. Conventionally, kinetics cell experiments are used to find the reaction parameters for the suggested models. Clearly, the number of crude-oil components and their potential reaction intermediates is very large thereby suggesting the use of pseudo-components. Direct implementation of the detailed reaction models based on pseudo-components in full field simulation of in-situ combustion is not currently feasible because fine spatial grids are needed to resolve the details of combustion front propagation accurately. Hence, a rigorous reaction upscaling procedure for in-situ combustion is an open area of study. In addition, the accuracy of reaction models that are tuned to kinetics cell experiments is questionable when they are used to simulate the combustion process. The heating rate (10's ◦ C/min) as the combustion front propagates is much larger than the current working limits of conventional furnaces employed in kinetics measurements. This thesis presents the design, verification, and validation of a new reactor for use in measuring crude-oil oxidation kinetics. The reactor is able to cover a range of heating rate from 1 to 30 ◦ C/min and is, thus, capable of reaching the heating rate of the combustion front. The new reactor allows rapid experimentation allowing measurements at a large number of distinct heating rates. A novel method for simulation of in-situ combustion is proposed that uses such kinetics cell measurements. The method naturally upscales reactions in a technique that is free of a reaction model. Results of the ramped temperature oxidation experiments are used directly to predict the oxidation profile for any arbitrary temperature history. The predictability of the technique is tested using results from two synthetic reaction models and experimental results from crude-oil samples. The applicability of the technique to flow simulation is demonstrated in one and two dimensions. Flow simulation results using the upscaling procedure are compared directly to a commercial simulator that implements full reaction kinetics. In all cases, good prediction of combustion dynamics is obtained.
Measurements of nonreciprocity in materials with a sagnac interferometer [electronic resource]
Keywords: Physics.

A modified Sagnac Interferometer has historically been used as an elegant technique for detecting non-reciprocal phenomena, such as rotation and magnetism. I will discuss how its function relies on the concept of reciprocity, and how it may be employed as a strategy for high-precision measurements testing a variety of broken symmetries. Previous designs of the interferometer have incorporated free-space components that are bulky and difficult to align. We have improved upon this technique by using all fiber-optic coupled components and demonstrate operation at a new wavelength, 820 nm, with which we can achieve better than 1 microradian resolution. Mounting the system on a piezo-electric scanner allows us to acquire diffraction limited images with 1.5 micrometer spatial resolution. This thesis discusses, in detail, the fundamental principles behind the interferometer, with emphasis on reciprocity, and the fine points of its construction. We report measurements of several magnetic materials. In addition, several observations of a nonlinear magneto-optical Kerr Effect have been noticed, and we report on these. Furthermore we discuss how chiral materials, or in general, materials which break mirror-symmetry can not give rise to a Kerr effect. Finally, we discuss extensions to the Sagnac Interferometry metrological technique and that allow the instrument to measure other optical effects which test for other broken symmetries.
Measurements of vibrational relaxation and dissociation of oxygen with laser absorption spectroscopy with applications for energy transfer in nonequilibrium air [electronic resource]
Keywords: Mechanical Engineering.

The vibrational relaxation times of oxygen were measured using laser absorption spectroscopy behind incident and reflected shocks in a shock tube. The Bethe-Teller equation was used to model the vibrational relaxation, which along with the shock jump relations were used to model the gasdynamic conditions throughout the nonequilibrium relaxation process. The absorbance was modeled based on these gasdynamic conditions while adjusting the vibrational relaxation time to fit the model to the measured oxygen absorbance time-history at wavelengths 210 - 230 nm in the Schumann-Runge system. Undiluted oxygen was studied behind incident shocks at initial post-shock translational/rotational temperatures from 1000 - 3300 K and pressures from 0.05 to 0.7 atm while a mixture of 2% oxygen in argon was studied behind incident and reflected shocks at initial translational/rotational temperatures from 1000 - 4000 K and pressures from 0.2 to 1 atm. Good agreement was found with prior experimental work by White and Millikan, Losev and Generalov, and Camac, though the current relaxation time data have less scatter and reduced uncertainty. The current results are also in excellent agreement with the well-known relaxation time recommendations of Millikan and White. The dissociation rate coefficient for oxygen in argon, O2 + Ar < => O + O + Ar, was measured using laser absorption near 216 nm in the Schumann-Runge system in a shock tube. A mixture of 2% oxygen in argon was studied behind reflected shocks at initial equilibirum temperatures from 4400 - 7900 K and pressures from 0.2 to 1 atm. The dissociation was modeled de-coupled from vibrational relaxation, as dissociation was evident only after the test gas mixture was near vibrational equilibrium. The dissociation rate coefficient was determined by fitting the measured oxygen absorbance time-history for each experiment using temperatures based on the incident shock speed and the shock relations and adjusting the A-factor of the dissociation rate coefficient. Good agreement was found with the prior experimental work and model of Camac and Vaughan. Consistent results were also obtained for measurements with constant pressure as well as increasing pressure, validating our method to account for pressure changes by including the pressure profile in the dissociation model.
Measuring conformational dynamics of biological molecules with single-molecule tracking and fluorescence correlation spectroscopy [electronic resource]
Keywords: Applied Physics.

The past two decades have seen great advances in single-molecule techniques capable of probing biomolecular systems with spatial resolution down to the nanometer level. However few techniques are specifically designed to measure larger scale organization between a few tens and a few hundreds of nanometers, especially when other figures of merit are considered, such as high time-resolution or the possibility to do measurements in bulk and without immobilization. Such features would be particularly useful in the study of molecular structures like chromatin or other nucleoprotein complexes, that exhibit organizational details and dynamics across a broad range of time and length scales. I present how the combination of fluorescence correlation spectroscopy (FCS) and single molecule tracking can be used to measure the conformational dynamics of molecules that diffuse freely in solution, at the scale of a few tens of nanometers. I discuss some aspects of the instrumentation as well as the parameters that define the spatial and temporal resolution. I describe other advantages of the technique such as the possibility to bypass a common difficulty associated with fluorescence correlation measurements and obtain a signal that is not convolved with the blinking dynamics of the fluorescent probe itself. Finally I present an experimental proof-of-principle where tracking-FCS was applied to measure the end-to-end Brownian dynamics of short DNA fragments in the semilflexible regime.
Measuring the interaction rate and characterizing the temporal interaction distribution of red harvester ants in foraging colonies
Keywords:  Department of Biology
Biology
Behavioral Ecology
Ant Colonies
Networks
Decision Making
Foraging
Thesis

Ant colonies operate without central control. Individual ants respond to local interactions with other ants, and in the aggregate, this allows colonies to regulate their behavior and respond to changing conditions. Dr. Gordon’s lab investigates how red harvester ants (Pogonomyrmex barbatus) use the rate of interactions in task decisions. Previous work shows that the rate of incoming, successful foragers determines the rate of outgoing foragers (Greene et al. 2013) and that ants experience an increase in interactions shortly before they choose to forage (Pinter-Wollman et al. 2013). However, it had not been shown that ants that choose to forage experience a different rate of interactions from ants that choose to stay in the nest. By directly observing and recording interactions, I demonstrated that ants that chose to forage experienced a significantly higher rate of interactions than ants that did not forage. Additionally, these foraging ants spent significantly less time interacting with other ants than ants that ultimately chose not to forage. These conclusions were based on observing and recording all interactions experienced by 90 outgoing foragers and 44 non-foragers from three nests across three days. For each colony and day, I also quantified what percentage of ants that left the deeper nest ultimately engaged in foraging, nest maintenance, or neither, and I found similar outcome distributions among the colonies. Finally, I attempted to measure the decay rate of the effect of an interaction for foraging harvester ants of different colonies. Restraint in foraging is a heritable trait that contributes to reproductive success, so I hypothesized that I would find consistent differences in the decay rate of the experience of an interaction in ants of different colonies and that these differences may suggest a mechanism for differences in foraging regulation (Gordon 2013).
Measuring the polarization of the cosmic microwave background with the Keck Array and Bicep2 [electronic resource]
Keywords: Physics.

Inflation, the theory that the early universe underwent a brief period of exponential expansion, extends the standard model of cosmology to resolve the isotropy, flatness, entropy, and monopole problems. Quantum fluctuations in the inflationary field set the initial seeds of matter which became the temperature anisotropies in the cosmic microwave background (CMB) and later formed the large scale structures of the universe. Quantum fluctuations of the gravitational field during inflation are predicted to produce a stochastic background of gravitational waves which would leave an imprint in the B-mode (curl) component of the polarization of the CMB, with an amplitude dependent on the energy scale of inflation. Bicep2 and the Keck Array are telescopes designed specifically to measure the B-mode polarization at degree-angular scales. They are a set of cryogenically cooled telescopes with refracting, on-axis optics with an aperture of 26.4 cm. The Keck Array has a combined imaging array of 2500 antenna-coupled TES bolometers read with a SQUID-based time-domain multiplexing system. All five of the Keck Array telescopes observed a 400 square degree patch from the South Pole at 150 GHz in 2012-2013, with an achieved sensitivity of 9 micro-K/rt(s) for the 2013 season. This thesis will focus on the optimization and characterization of the Keck Array, as well as the combined cosmology results from the Keck Array with Bicep2. The Keck Array data are consistent with the Bicep2 detection of B-mode polarization at degree-angular scales and increases the sensitivity of the measurement by a factor of 2.
Mechanism of Furosemide on GABAergic Circuits
Keywords:  Department of Biology
Epilepsy
Furosemide
GABA
Electrophysiology
Neuroscience
Biology
Stanford
Thesis

Enhancement of GABA-mediated synaptic inhibition is one of the mechanisms by which inhibition of central nervous system is controlled. This appears to be achieved through a potentiation of postsynaptic GABA receptor activity. Among two types of GABA receptors (GABA-A and GABA-B), GABA-A signaling enhancement has been found to be an important contributor to nervous system depression by several anesthetics The aim of proposed research was to specify the effect of GABAA Antagonist furosemide on epileptic brain slice. For this objective, we use several in vitro epileptic conditions which accurately reflect the physiological ionic and pH changes associated with epileptic condition. We tested what change happened after introduction of furosemide and qualified the mechanism in which part of the brain this drug acted on and proposed the further aspects of use of anesthetics on epilepsy.
Mechanisms of resistance switching in various transition metal oxides [electronic resource]
Keywords: Electrical Engineering.

Several materials, especially transition metal oxides, undergo abrupt changes in resistance, known as resistance switching, driven by various external stimuli such as temperature, electric field, etc. through several mechanisms such as Mott transition, Peierls transition, etc. Such a change in resistance and other intrinsic material properties have enabled many applications, specifically, in an upcoming computer memory technology called Resistive Random Access Memory (RRAM), where information is stored in distinct resistance states of the material, owing to the phase-transition. In this work, we understand mechanisms of phase transitions in two oxide systems, namely, VO2 and TaOx+TiOx. We use multiple advanced in-situ spectro-microscopy techniques to understand the switching process driven by different stimuli including uniform material temperature and local Joule-heating.
Medical image similarity perception for content-based image retrieval [electronic resource]
Keywords: Electrical Engineering.

Content-based image retrieval (CBIR) of perceptually similar images for medical decision support may improve the accuracy and efficiency of radiological diagnosis. A robust reference standard for perceptual similarity in medical images is vital to CBIR applications, but is challenging to create due to the large amount of observer data necessary as well as high inter-observer variability. The aims of this thesis are (1) to develop techniques for creating reference standards based on perceptual similarity that are scalable for large databases, and (2) to model inter-reader variability in observer assessments of image similarity. This thesis first discusses a novel technique for predicting visual similarity for pairs of images in a database from perceptual data obtained by viewing each image individually. In an observer study using 19 CT liver lesions in the portal venous phase, three radiologists provided point-wise ratings for visual attributes of images containing liver lesions displayed individually and also for perceptual similarity in all pair-wise combinations of these images. Using the data generated from viewing images individually, this work develops a scheme to generate ratings of pair-wise similarity using linear fitting, and demonstrates that this is a scalable technique for developing a reference standard. This work also develops a statistical model from these data that may be used to predict inter-reader variability and accuracy of similarity estimates in larger sets of data. Finally, this thesis discusses leveraging compressive sensing techniques, which may be used to complete highly sparse matrices, to impute similarity matrices from a small subset of observer ratings. By being scalable for large databases, this technique may be a reliable and efficient method for creating similarity reference standards. The results of this work thus provide a better understanding of perception of medical image similarity, which may in turn be used to train and validate medical decision support systems.
Memory-efficient image databases for mobile visual search [electronic resource]
Keywords: Electrical Engineering.

Mobile visual search (MVS) systems compare query images captured by the mobile device's camera against a database of labeled images to recognize objects seen in the device's viewfinder. Practical MVS systems require a fast response to provide an interactive and compelling user experience. We show how a memory-efficient database stored on a mobile device can effectively enhance the capabilities of MVS systems and enable fast and accurate queries in different environments. The image signatures stored in the database on the mobile device must be compact to fit in the device's small memory capacity, capable of fast comparisons across a large database, and robust against large visual distortions. We first develop two methods for efficiently compressing a database constructed from feature histograms. Our methods reduce the database memory usage by 4-5 times without any loss in matching accuracy and possess fast decoding capabilities. Subsequently, we develop a third database representation based on feature residuals that is even more compact. Compressed residuals reduce the database memory usage by 12-14 times, require only a small codebook, and enable image matching directly in the compressed domain. With a compact database stored on a mobile device, we implement an MVS system that can recognize media covers, book spines, outdoor landmarks, artwork, and video frames in less than 1 second per query. Our system uses robust motion analysis on the device to automatically infer user interest, select high-quality query frames, and update the pose of recognized objects for accurate augmentation. We also demonstrate how a continuous stream of compact image signatures enables a low bitrate query expansion onto a remote server. The query expansion improves image matching during the current query and updates the local on-device database to benefit future queries.
Metal insulator multi-layer surface plasmon devices [electronic resource]
Keywords: Materials Science and Engineering.

Surface plasmon based devices have attracted significant of attention over the last decade with exciting applications like negative refraction, optical cloaking, perfect lenses, and meta-surfaces. They have also enabled highly efficient and compact electro-optical devices bridging the gap between optical (micron) and the electronics (nano) scale devices. At the heart of many of these devices and applications are multi-layer metal insulator structures, where the interaction of surface plasmons at various interfaces unlock these surprising properties. This thesis focuses on the scattering and transmission properties of plasmon modes in metal insulator multilayer structures. In the first part of the thesis, we will describe a theoretical model for standing wave resonances in Metal-Insulator-Metal surface plasmon cavities. These calculations, which are in excellent agreement with full field finite difference simulations, aid in furthering our understanding of plasmon phase pickup on reflection from the cavity terminations. This phase pickup is associated with the near-field energy storage at those terminations, and the imaginary part of the reflection coefficient is shown to be approximately proportional to the stored energy. We then focus on a different, yet related geometry for a surface plasmon antenna, a metal stripe wave guide above a metallic ground plane. Staggered confocal microscopy is used to study the scattering properties of the stripe antenna. CdSe/ZnS quantum dots are sandwiched between the stripe and ground plane. Dual purposing of the stripes as electrical lead and an optical element is illustrated through low temperature quantum confined stark effect measurements. Finite difference calculations of the surface plasmon transmission spectra through the truncated stripe waveguide cavity is shown to be well modeled by a two-path-two-mode coupled cavity model.