Investment analysis and future potential of controlled-environment agriculture hydroponic production systems for Boston lettuce

Ilaslan, Gunes Cornell University 2000 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Cornell University's Controlled Environment Agriculture (CEA) program has been involved in greenhouse hydroponic vegetable production research since 1991. The unique aspect of the CEA system developed by Cornell University is accurate greenhouse climate control and integration of supplemental lighting to provide consistent year-round rapid plant growth, which results in higher yield than any other existing systems. Boston lettuce, <italic>Lactuca sativa cv</italic>. ‘<italic>Vivaldi </italic>’, grown under CEA conditions achieves the same quality and quantity of product everyday of the year. The CEA system creates many advantages, providing efficient use of nutrients, water, and labor while assuring better control of the plant development that results in earlier production, higher yields, and a qualitatively better product. The product, hydroponic lettuce, will be marketed as great tasting, fresh, locally-grown, safe (produced following the Hazard Analysis and Critical Control Point, HACCP, principles) and pesticide-free. These features, combined with year-round constant quantity and quality production, indicate potential for success. In the introductory stage of this CEA technology, it is crucial to determine the economic feasibility of the system, as it requires a large capital investment and sophisticated technical knowledge to operate. This study assessed production costs and economic viability of the production system in nine different US locations under different climatic conditions. This research is expected help the prospective owner or operators to make a more informed investment decision. A commercial-sized CEA demonstration greenhouse in Ithaca, NY is used as a reference for input data. A net present value analysis (NPV) is performed to determine the profitability of the system. The NPV analysis also provided the minimum price at which the product should be sold in order to receive enough revenue to cover all of the associated production costs and provide the rate of return required for the capital invested. The highest grower price required for economic feasibility of CEA system was in Ithaca, NY whereas the lowest price needed was in Miami, FL. The effects of various inputs including product price, electricity, and heating costs on economic feasibility of CEA hydroponic lettuce operations were also evaluated. The results of the one-way sensitivity analysis showed the product price, production level, and initial investment were the most important variables on the profitability of the all potential locations. A quantitative risk analysis of Monte Carlo simulation was also incorporated into the CEA hydroponic system investment analysis. The risk level of the investment was the highest in Los Angeles, CA while lowest in Miami, FL. The results revealed that, under uncertainty, grower prices to receive a minimum positive mean net present value have to be a couple cents higher than the grower price required for economic feasibility. The implications of economic pressure created by other hydroponic lettuce producing locations if a price premium can not received be for the local producer was studied. The results indicated that all selected locations except for Chicago, Ithaca, and Los Angeles markets provided the cheapest hydroponic lettuce to their own local market.

A comparative case study of Black student responses to diversity-related media at one U.S. and one Canadian university

Butler, Alana Corinne Cornell University 2015 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

This doctoral dissertation is a qualitative comparative case study about Black student responses to diversity-related print and web material at one Canadian and one American university. The research methodologies used in this study included: 1) a critical discourse analysis of diversity-related media and policy documents and 2) a thematic narrative analysis of in-depth interviews. A cross-sectional sample of forty-two students were selected for in-depth interviews between both universities. A sample of twelve Diversity administrators were also interviewed for the study. The central research question asked how Black students articulated their experiences in response to diversity-related media within their universities. This study drew on several overlapping theoretical frameworks. These theoretical frameworks included color-blind racism (Bonilla-Silva, 2014), critical discourse analysis (Fairclough, 1995), institutional diversity and language (Ahmed, 2012), and lastly I considered the agency of the students as demonstrated through their use of counter-hegemonic discourses. The main findings from the textual and visual analysis of media was that both universities conceptualized diversity as differences in visible social identities. The institutional emphasis was on the diversity of the student population and managerial diversity discourses were fully integrated in brochures, web sites, and policy statements. Students in Canada and the U.S. generally reported similar experiences. Most students observed contradictions between their experiences and the institutional diversity discourses. Diversity administrators felt silenced and disillusioned by the lack of change that they were able to effect. This study connects diversity policies and practices in higher education. The findings also illuminate some of the tensions and current challenges about race and higher education.

Essays on carbon abatement and electricity markets

Taber, John Timothy Cornell University 2012 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

In the first chapter of this dissertation, I study the effects of a number of policies which affect the electric grid using the SuperOPF, a full AC optimization/simulation framework with optimal investment developed at Cornell University. A 36-node model of the Northeast Power Coordinating Council is used to test policies that aim to reduce CO2, other emissions, or otherwise impact the operation of the electric grid: a base case, with no new environmental legislation; enactment of the Kerry-Lieberman CO2 allowance proposal in 2012; following Fukishima, a retirement of all US nuclear plants by 2022 with and without Kerry-Lieberman; marginal damages from SO2 and NOX emissions charged to coal, gas and oil-fired generation; plug-in hybrid electric vehicle load filling; wind incentives in place; and two cases which combine these. The cases suggest that alternative policies may have very different outcomes in terms of electricity prices, emissions, and health outcomes. In all cases, however, the optimal strategy for future investment is investment in new natural gas combined cycle plants. Policies can change how much new generation is built, whether other plants are built, or what types of plants are retired. The second chapter of my dissertation utilizes the SuperOPF and the model of the Northeast Power Coordinating Council to analyze the issue of carbon leakage. I analyze the effects of a regionally-limited carbon cap and trade program, the Regional Greenhouse Initiative (RGGI), when additional generating assets in non-affected states are included in the analysis. In the face of different carbon prices on generating assets in covered and non-covered states, generation is expected to shift from states bound by RGGI to states outside of RGGI. This carbon leakage may undermine some or all of the benefits of RGGI while simultaneously increasing prices for customers in the area. Even though carbon prices under RGGI are very low, some leakage is occurring, and this leakage will worsen if carbon prices increase. Ultimately, a unified policy offers greater carbon reduction at a lower cost, which would increase popular acceptance of such policies. In the third chapter of this dissertation, my coauthors and I examine the issue of demand for carbon reductions. Recent large-scale field experiments have shown that peer information nudges can have significant effects on behavior, inducing people to reduce their production of negative externalities. Related work in psychology demonstrates that inducing feelings of personal culpability by showing people information about their peers can induce pro-social behavior. This study uses a contingent valuation experiment and a parallel lab experiment to further explore patterns of responses that have been suggested in the emerging literature on norm-based environmental interventions The field--level finding of asymmetric responses between those whose environmental or group impacts are above or below the norm is found to be robust across decision settings. However, substantial heterogeneity in responses to peer information is observed across a number of demographic and other respondent--specific dimensions not able to be explored in large scale field experiments, raising questions about the universality of peer-information effects and the design of such programs.

Essays in Behavioral and Labor Economics : Ensayos en Economia del Comportamiento y Laboral

Reyes, German Cornell University ProQuest Dissertations & Theses 2023 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Just like factories require physical capital-machinery, buildings, tools-to produce output, workers rely on their human capital-abilities, skills, knowledge-to accomplish job tasks. Human capital is a fundamental determinant of worker productivity and, consequently, of wages. But human capital and wages are not determined in a vacuum. Market participants like universities, firms, and peer networks shape the production of human capital and the determination of wages.This dissertation examines behavioral or "nonstandard" forces that determine human capital and affect the price of labor. I show that cognitive endurance is a highly-rewarded skill in the labor market (Chapter 1), that limited firm sophistication affects the distribution of wages (Chapter 2), and that the wage return to attending elite universities is closely linked to the value of their alumni networks (Chapter 3).In Chapter 1, "Cognitive Endurance, Talent Selection, and the Labor Market Returns to Human Capital," I study the importance of cognitive endurance-the ability to sustain performance on a cognitively-demanding task over time-for success in college and the labor market. I use college-admission-exam records from 15 million Brazilian high school students and develop a method to decompose test scores into fatigue-adjusted ability and cognitive endurance. I find that cognitive endurance has a significant wage return. Controlling for fatigue-adjusted ability and other student characteristics, a onestandard-deviation higher endurance predicts a 5.4% wage increase. I also document positive associations between endurance and college attendance, college quality, college graduation, firm quality, and other outcomes. Finally, I show how systematic differences in endurance across students interact with the exam design to determine the sorting of students to colleges.In Chapter 2, "Coarse Wage-Setting and Behavioral Firms," I study why firms often pay new hires round-numbered salaries-a puzzling fact from the perspective of canonical wage-determination models. I posit that, in the presence of uncertainty about the fully-optimal salary, firms might rely on a rule of thumb or heuristic as an approximation-a form of pricing I refer to as "coarse wage-setting." I test this hypothesis using contracted salaries of 280 million hires in Brazil. First, I show that firms that tend to hire workers at round-numbered salaries are less sophisticated and have worse market outcomes. Motivated by this reduced-form evidence, I develop a wage-posting model in which optimization frictions lead to the adoption of coarse wages and provide evidence supporting three predictions of the model using two research designs. Finally, I show that coarse wage-setting generates within-firm wage compression, increases nominal wage stickiness, and interacts with policies that affect the wage distribution, such as changes in the minimum wage.In Chapter 3, "The Direct and Spillover Effects of Large-scale Affirmative Action at an Elite Brazilian University" (with Cecilia Machado and Evan Riehl), we study a selective university in Brazil that adopted large-scale race- and income-based affirmative action. We link admission records to national employer-employee data to show that a key benefit of attending the university is access to high-paying firms affiliated with its alumni. We find that affirmative action increased disadvantaged students' access to these firms and raised their early-career earnings. But both of these benefits faded as their careers progressed. In addition, the increase in student body diversity lowered the job prospects and earnings of the university's most highly ranked students. Our findings show that affirmative action may be less effective at reducing income disparities when the benefits of admission depend on a university's alumni networks. l igual que las fabricas requieren de capital fisico-maquinas, edificios y herramientas-para producir bienes y servicios, los trabajadores dependen de su capital humano-habilidades, destrezas y conocimientos-para llevar a cabo tareas laborales. El capital humano es un determinante fundamental de la productividad de los trabajadores y, por lo tanto, de los salarios. Sin embargo, el capital humano y los salarios no se determinan en el vacio. Los agentes del mercado, como universidades, empresas y conexiones sociales, influyen en la produccion de capital humano y la determinacion de los salarios.Esta disertacion examina factores "no estandar" que determinan el capital humano y afectan el precio del trabajo. Demuestro que la resistencia cognitiva es una habilidad altamente recompensada en el mercado laboral (Capitulo 1), que la limitada sofisticacion de las empresas afecta la distribucion de los salarios (Capitulo 2) y que el retorno salarial de asistir a universidades de elite esta estrechamente vinculado al valor de sus redes de exalumnos (Capitulo 3).En el Capitulo 1, "Resistencia cognitiva, seleccion de talento y rendimientos del capital humano en el mercado laboral", estudio la importancia de la resistencia cognitiva-la capacidad de mantener el rendimiento en una tarea cognitivamente exigente a lo largo del tiempo-para el exito en la universidad y el mercado laboral. Utilizo registros de examenes de ingreso a la universidad de 15 millones de estudiantes de secundaria brasilenos y desarrollo un metodo para descomponer las puntuaciones de las pruebas en habilidad ajustada por fatiga y resistencia cognitiva. Encuentro que la resistencia cognitiva tiene una prima salarial significativa. Controlando por la habilidad ajustada por fatiga y otras caracteristicas de los estudiantes, una resistencia superior en una desviacion estandar predice un aumento salarial del 5,4%. Tambien documento asociaciones positivas entre la resistencia cognitiva y la asistencia a la universidad, la calidad de la universidad, la graduacion universitaria, la calidad de la empresa y otras variables. Finalmente, muestro como las diferencias sistematicas en la resistencia entre los estudiantes interactuan con el diseno del examen para determinar la clasificacion de los estudiantes en las universidades.En el Capitulo 2, "Determinacion salarial tosca y conducta no estandar de las empresas", estudio por que las empresas a menudo pagan a los nuevos empleados salarios en numeros redondos, un hecho desconcertante desde la perspectiva de los modelos canonicos de determinacion de salarios. Postulo que, en presencia de incertidumbre sobre el salario optimo, las empresas usan heuristicas como una aproximacion, una forma de fijacion de salario a la que me refiero como "determinacion salarial tosca". Pongo a prueba esta hipotesis utilizando los salarios de 280 millones de trabajadores en Brasil. Primero, muestro que las empresas que tienden a contratar trabajadores con salarios redondos son menos sofisticadas y tienen peores resultados en el mercado. Motivado por estos hechos estilizados, desarrollo un modelo de fijacion de salarios en el que fricciones de optimizacion llevan a la adopcion de salarios toscos y proporciono evidencia que respalda tres predicciones del modelo utilizando dos estrategias empiricas. Finalmente, muestro que el establecimiento de salarios toscos genera compresion salarial dentro de la empresa, aumenta la rigidez salarial nominal e interactua con politicas que afectan la distribucion de salarios, como cambios en el salario minimo.En el Capitulo 3, "Los efectos directos y de derrame de la accion afirmativa a gran escala en una universidad brasilena de elite" (con Cecilia Machado y Evan Riehl), estudiamos una universidad selectiva en Brasil que adopto una politica de accion afirmativa a gran escala basada en raza e ingresos. Vinculamos los registros de admision con datos nacionales de empleadores y empleados para demostrar que un beneficio clave de asistir a la universidad es el acceso a empresas que pagan alto salarios y que estan afiliadas a su red de exalumnos. Descubrimos que la accion afirmativa aumento el acceso de los estudiantes desfavorecidos a estas empresas e incremento sus ingresos iniciales en la carrera. Sin embargo, ambos beneficios disminuyeron a medida que sus carreras avanzaron. Por otra parte, el aumento en la diversidad del cuerpo estudiantil redujo las perspectivas laborales y los ingresos de los estudiantes mas destacados de la universidad. Nuestros hallazgos muestran que la accion afirmativa puede ser menos efectiva para reducir las disparidades de ingresos cuando los beneficios de la admision dependen de las redes de exalumnos de la universidad.

Development of the 2nd generation z(Redshift) and Early Universe Spectrometer & the study of far-IR fine structure emission in high-z galaxies

Ferkinhoff, Carl Cornell University 2014 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

The 2nd generation z (Redshift) and Early Universe Spectrometer (ZEUS-2), is a long-slit echelle-grating spectrometer (R∼1000) for observations at submillimeter wavelengths from 200 to 850 microm. Its design is optimized for the detection of redshifted far-infrared spectral lines from galaxies in the early universe. Combining exquisite sensitivity, broad wavelength coverage, and large (∼2.5%) instantaneous bandwidth, ZEUS-2 is uniquely suited for studying galaxies between z∼0.2 and 5---spanning the peaks in both the star formation rate and number of AGN in the universe. ZEUS-2 saw first light at the Caltech Submillimeter Observatory (CSO) in the Spring of 2012 and was commissioned on the Atacama Pathfinder Experiment (APEX) in November 2012. Here we detail the design and performance of ZEUS-2, first however we discuss important science results that are examples of the science enabled by ZEUS-2. Using the first generation z (Redshift) and Early Universe Spectrometer (ZEUS-1) we made the first high-z detections of the [NII] 122 microm and [OIII] 88 microm lines. We detect these lines from starburst galaxies between z ∼2.5 and 4 demonstrating the utility of these lines for characterizing the properties of early galaxies. Specifically we are able to determine the most massive star still on the main sequence, the number of those stars and a lower limit on the mass of ionized gas in the source. Next we present ZEUS-2's first science result. Using ZEUS-2 on APEX we have detected the [CII] 158 microm line from the z = 1.78 galaxy H-ATLAS J091043.1-000322 with a line flux of (6.44 +/- 0.42) x 10-18 W m-2. Combined with its far-infrared luminosity and a new Herschel-PACS detection of the [OI] 63 microm line we are able to conclude that H-ATLAS J091043.1-000322 is a high redshift analogue of a local ultra-luminous infrared galaxy, i.e. it is likely the site of a compact starburst due to a major merger. This detection, combined with the ZEUS-1 observations of the [NII] and [OIII] lines represent examples of work we plan to continue with ZEUS-2. As such, they demonstrate the potential of ZEUS-2 for increasing our understanding of galaxies and galaxy evolution over cosmic time.

Observational and theoretical studies of mesospheric dynamics and bores using airglow imagers at mid-latitudes

Loughmiller, Pamela Jane Cornell University 2008 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

This dissertation focuses on the study of coupling-dynamics in the mesosphere. Interesting airglow phenomena---primarily internal bores occurring mid-latitude at mesospheric altitudes---have been observed and studied in a multifaceted approach, combining the analysis of experimental data with modelling and theory. After the initial mesospheric bore sighting by the scientific community in 1993, the next recorded events were observed by Cornell University. To gain additional insight, this investigation effectively pursued more data by installing imaging equipment as part of a collaborative, multi-instrument campaign involving lidar. While coincident lidar data eluded us, we did expand our database allowing us to develop the first classification system to categorize mesospheric bore observations. We also verify for the first time that a mesospheric inversion layer would support bore formation as proposed. Some of the bore data exhibits features unexpected and new. Most intriguing is that the brightness relationship between airglow layers is reversed and accompanied by a lateral shift! This was the first such "inverse" event reported in the scientific community, and its seemingly contradictory nature fails to support the existing basic theory. Working with researchers at the Air Force Research Laboratory, we propose a new theory extending the original numerical model. We also compare the data to another non-linear theory and find both that: (1) neither theory explains all the observable features, and (2) each theory succeeds in explaining some characteristics not addressed by the competing theory. This theory development suggests that mesospheric bores likely are nonlinear structures propagating within upper atmospheric waveguides such as thermal-inversion layers or wind-shear ducts. Well into this thesis, we realized the critical and complicated role calibration plays in ensuring the condition of our data. Calibration reduces the discrepancies between the raw error-prone data and a true portrayal of the phenomena, facilitating the generation of congruent, accurate data for analysis. To address some of the calibration challenges and to alleviate some of the confusion for future graduate students, a portion of this dissertation is devoted to providing the first, comprehensive presentation of calibration---detailing topics, techniques, methodologies, and results, as they pertain to airglow imagers.

Statistical analysis of ALFALFA galaxies: Insights in galaxy formation & near-field cosmology

Papastergis, Emmanouil Cornell University 2013 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

The Arecibo Legacy Fast ALFA (ALFALFA) survey is a blind, extragalactic survey in the 21cm emission line of atomic hydrogen (HI). Presently, sources have been cataloged over ≈4,000 deg2 of sky (~60% of its final area), resulting in the largest HI-selected sample to date. We use the rich ALFALFA dataset to measure the statistical properties of HI-bearing galaxies, such as their mass distribution and clustering characteristics. These statistical distributions are determined by the properties of darkmatter on galactic scales, and by the complex baryonic processes through which galaxies form over cosmic time. As a result, detailed studies of these distributions can lead to important insights in galaxy formation & evolution and near-field cosmology. In particular, we measure the space density of HI-bearing galaxies as a function of the width of their HI profile (i.e. the velocity width function of galaxies), and find substantial disagreement with the distribution expected in a lambda cold dark matter (LambdaCDM) universe. In particular, the number of galaxies with maximum rotational velocities upsilonrot ≈ 35 kms--1 (as judged by their HI velocity width) is about an order of magnitude lower than what predicted based on populating LambdaCDM halos with modeled galaxies. We identify two possible solutions to the discrepancy: First, an alternative dark matter scenario in which the formation of low-mass halos is heavily suppressed (e.g. a warm dark matter universe with keV-scale dark matter particles). Secondly, we consider the possibility that rotational velocitites of dwarf galaxies derived from HI velocity widths may systematically underestimate the true mass of the host halo, due to the shape of their rotation curves. In this latter scenario, quantitative predictions for the internal kinematics of dwarf galaxies can be made, which can be checked in the future to probe the nature of dark matter. Furthermore, we take advantage of the overlap of ALFALFA with the Sloan Digital Sky Survey (SDSS), to measure the number density of galaxies as a function of their "baryonic" mass (stars + atomic gas). In the context of a LambdaCDM cosmological model, the measured distribution reveals that low-mass halos are heavily "baryon depleted", i.e. their baryonic-to-dark mass ratio is much lower than the cosmological value. These baryon deficits are usually attributed to stellar feedback (e.g. supernova-driven gas outflows), but the efficiency implied by our measurement is extremely high. Whether such efficient feedback can be accommodated in a consistent picture of galaxy formation is an open question, and remains one of the principle scientific drivers for hydrodynamic simulations of galaxy formation. Lastly, we measure the clustering properties of HI-selected samples, through the two-point correlation function of ALFALFA galaxies. We find no compelling evidence for a dependence of clustering on HI mass, suggesting that the relationship between galactic gas mass and host halo mass is not tight. We furthermore find that HI galaxies cluster more weakly than optically selected ones, when no color selection is applied. However, SDSS galaxies with blue colors have very similar clustering characteristics with ALFALFA galaxies, both in real as well as in redshift space. On the other hand, HI galaxies cluster much more weakly than optical galaxies with red colors, and in fact "avoid" being located within ≈3 Mpc from the latter. By considering the clustering properties of LambdaCDM halos, we confirm our previous intuition for an MHI-Mh relation with large scatter, and find that spin parameter may be a key halo property related to the gas content of present-day galaxies.

Saving time: New methods and instrumentation for radio variability studies

Spitler, Laura Grace Cornell University 2013 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

My thesis describes new instrumentation and signal processing techniques developed for time-domain studies of the radio sky and applies these techniques to a variety of radio astronomical data. Time-domain algorithms were developed for the SERENDIP V survey, a commensal SETI survey operating at the Arecibo Observatory. Along with collaborators at the University of California at Berkeley, I helped develop the high frequency resolution digital FFT spectrometers used to collected the data. No signal with the characteristics of being from an extraterrestrial intelligence was observed. A method for automatically classifying broadband and narrowband signals in raw frequency-time data is presented. It uses both the first and second moments of a spectrum to characterize the how broad or narrowband a signal is. Our applications of this technique to real data show that this algorithm is an effective tool for radio frequency interference excision. A survey for rare, bright radio transients was undertaken with a 3.8 m radio telescope on the roof of the Space Sciences Building on Cornell’s campus. This survey involved the end-to-end development of the hardware, software, and data analysis. The data were searched from single, dispersed pulses, but none were found. Multi-frequency observations of the eclipsing, binary white dwarf system J0651 were conducted at the Arecibo Observatory to search for variable emission, both short-duration, “burst-like” and periodic emission. The system has an orbital period of only 12.75 min, and this fast rotation may generate radio emission if the stars are magnetic, but no emission was seen. Five new pulsars, including three Rotating Radio Transients (RRATs), were discovered in a single pulse analysis of 23 months of Pulsar ALFA (PALFA) data collected with the Mock spectrometers. We expanded the existing pipeline to include several new algorithms, including the spectral modulation index and a single pulse rating. In addition to the new discoveries, forty-seven previously known pulsars were redetected. From this work I conclude that considering the time domain is key to fully understanding the radio sky. Time-domain studies require special algorithms and instrumentation and particular attention must be made to managing radio frequency interference.

Jet and dark substructure: Rise of the machines

Cliche, Mathieu Cornell University 2015 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

We currently live in the golden age of experimental particle physics. The Large Hadron Collider (LHC) finally discovered the Higgs particle and may soon allow us to probe TeVscale new physics. Moreover, dark matter indirect detection experiments may have found annihilation products in our galaxy while the direct detection experiments keep improving their upper bounds on dark matter interactions with ordinary matter. That being said, the current efforts to discover any physics beyond the standard model have failed. We thus need to come up with better models and better tools to probe new physics. This thesis which collects the author's PhD research papers is an effort in this direction. We begin by showing how singular dark matter self-interaction can significantly enhance dark matter annihilation in today's Universe. Then we explore a concrete dark matter model where a particle called the dilaton mediate the interactions between the dark sector and the standard model. Finally we devise a new method to discern heavy boosted particles from QCD jets at the LHC.

ATMOSPHERIC STUDIES USING ALL-SKY IMAGING OF AIRGLOW LAYERS (LINEAR GRAVITY WAVE)

GARCIA, FRANCISCO JOSE CORNELL UNIVERSITY 1999 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

This thesis concerns the analysis of all-sky airglow image data. The basic airglow chemistry and linear gravity wave theory is reviewed. A model for the image data is presented as well as a method for the analysis of the data in both the spatial and frequency domains. The CU All-Sky Imager, which is a new addition to Cornell's array of remote sensing instruments, was developed to be a portable and remotely controllable airglow observatory as part of this dissertation. Data taken with this imager from the mid latitude sites of Puerto Rico, Hawaii and New York are presented and analyzed. The mesospheric data show a predominance of ripple-like small scale structure with wavelengths generally less than 20 km. In addition, a series of sharp fronts were observed and are discussed in the context of a recently proposed theory attributing them to mesospheric bores. The thermospheric data presented show that, contrary to what has generally been believed, the thermosphere at magnetic mid-latitudes is not quiescent. Routinely, southwest-aligned structures are evident. These structures often appear to be wave-like, indicating the possible involvement of a neutral wave. The Perkins instability is presented as a possible explanation for the existence of these structures. During the two most geomagnetically active nights (Kp > 6), the thermospheric airglow emission erupted into spectacular displays. These data sets represent the first time that such intricate substructure was captured with an airglow imager. Supporting data from a variety of satellite and ground-based instruments show that the magnetic storm conditions caused elevated plasma densities over Arecibo, and it is postulated that these conditions helped amplify the Perkins and gradient drift instabilities.