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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Waterbird use of Kentucky Reservoir mudflats

Wirwa, Drew W., January 2009 (has links) (PDF)
Thesis (M.S.)--University of Tennessee, Knoxville, 2009. / Title from title page screen (viewed on Oct. 28, 2009). Thesis advisor: Matthew J. Gray. Vita. Includes bibliographical references.
72

Irrigação plena e com déficit em diferentes estádios fenológicos da cultura do girassol no semiárido cearense / Full and deficit irrigation in different phenological stages of the sunflower cultivation in the Ceara semiarid.

Silva, Alexandre Reuber Almeida da January 2012 (has links)
SILVA, Alexandre Reuber Almeida da. Irrigação plena e com déficit em diferentes estádios fenológicos da cultura do girassol no semiárido cearense. 2012. 173 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Engenharia Agrícola, Programa de Pós-Graduação em Engenharia agrícola, Fortaleza-CE, 2012. / Submitted by demia Maia (demiamlm@gmail.com) on 2016-06-02T17:00:21Z No. of bitstreams: 1 2012_dis_ arasilva.pdf: 4268401 bytes, checksum: 9d9991a9608a69a78071f97d047a03c2 (MD5) / Approved for entry into archive by demia Maia (demiamlm@gmail.com) on 2016-06-02T17:02:02Z (GMT) No. of bitstreams: 1 2012_dis_ arasilva.pdf: 4268401 bytes, checksum: 9d9991a9608a69a78071f97d047a03c2 (MD5) / Made available in DSpace on 2016-06-02T17:02:02Z (GMT). No. of bitstreams: 1 2012_dis_ arasilva.pdf: 4268401 bytes, checksum: 9d9991a9608a69a78071f97d047a03c2 (MD5) Previous issue date: 2012 / Crops have phenological stages with less susceptibility to water deficit, in which the strategy of deficit irrigation management can be employed in order to maximize production per unit of irrigation water. Thus, the purpose of this research was to evaluate the responses of sunflower cultivation with full irrigation and with different water deficits durin g its phenological stages in order to collect information on the technical feasibility of the irrigation deficit in the sunflower crop, for the conditions of the semiarid in state of Ceara, Brazil. In the field the experiment was conducted at Experimental Farm Vale do Curu, in Pentecoste (Ceara, Brazil) under experimental design of randomized blocks with four replications and eight treatments, defined in function of the time of water deficit induction in the three sunflower phenological stages (vegetative, flowering and production formation), corresponding to the occurrence of water deficit in one, two or three stages. The water deficit irrigation level employed consisted of half the irrigation evaluated as being full irrigation. All the cultural and phytosanitary practices required was carried. In order to measure the effects of the treatments it was evaluated, at the end of each developmental stage, the following variables: leaf temperature, photosynthesis rates, transpiration, stomatal conductance, internal concentration of CO2, instantaneous efficiencies and intrinsic water use, plant height, quantity of leaf, stemdiameter, leaf area, dry biomass production of the constituents of the aerial part (stem, leaf, petiole and chapter) and the participation of each element in relation to the production of total dry matter (partition). On the occasion of harvest time, it was evaluated the components of production (diameter of chapter, mass of 1000 achenes and oil and protein content), the income potential of producing acheness, oil and protein, and the indices of efficiency of water use to produce achenes, oil and protein. The variables were subjected to statistical analysis, performing analysis of variance (F test) and Tukey's test to compare means. It was also determined the coefficients of sensitivity to water deficit (KY) isolated in stadiums and in the cycle of the crop through the relationship between relative income decrease and relative evapotranspiration deficit. The results presented that the temperature and leaf gas exchanges howed no effects of the applied water stresses, regardless of the time when these were applied. The times of evaluation influenced all variables related to gas exchange, except for the intrinsic efficiency of water use. The plant height, leaf number and stem diameter were negatively affected by the isolated effects of irrigation deficits and evaluation times. The irrigation deficit and the evaluation time interacted and affected leaf area, dry mass of leaf, petiole, stem, capitulum and total dry mass. The d eficit irrigation did not change the partition of dry matter. Changes were observed in capitulum diameter, in the mass of one thousand achenes, in the achene oil content, in the achene, oil and protein production potentials, and in the water use efficiency in the production of achenes and oil (for the applied water deficits). The management strategy of water deficit during the vegetative and flowering stages contributed to the achievement of an achene production potential at a level equivalent to that achieved in cultivation with full irrigation throughout the growing season. Regardless of the phenological phase, the water deficit exerted a positive effect on the efficiency of water use in the achene production. The incidence of water deficit during the flowering stage was more advantageous to the efficiency of water use in oil production than at any other stage, and did not influence the efficiency of water use in protein production, regardless of phenological stage on which it happened. Sensitivity to water deficit quantified by the coefficient of sensitivity to water stress (K Y) varied in the following decreasing order: production formation, vegetative and flowering, with water deficit occurring in only one developmental stage. For the deficit conditions in two stages, the coefficient KY showed that the lack of water has the greatest impact on sunflower achene yield when it occurs in both vegetative and production formation stages. As the K Y values were less than 1 at all stages, it is concluded that the sun flower culture showed a low sensitivity to the water deficits applied, showing, therefore, vulnerability to water deficit irrigation practice throughout its cycle. / As culturas agrícolas apresentam estádios fenológicos de menor suscetibilidade ao déficit hídrico do solo, nos quais a estratégia de manejo da irrigação deficitária pode ser empregada, no intuito de maximizar a produção por unidade de água aplicada. Assim, objetivou-se, com esta pesquisa, avaliar as respostas da cultura do girassol a irrigação plena e a diferentes regimes de déficit hídrico durante seus estádios fenológicos, visando reunir informações que permitam diagnosticar a viabilidade técnica da aplicação da irrigação deficitária na cultura, para as condições do semiárido cearense. Em campo, o experimento foi conduzido na Fazenda Experimental Vale do Curu, em Pentecoste – CE, sob delineamento experimental de blocos ao acaso, com quatro repetições e oito tratamentos, definidos em função da época de indução do déficit hídrico nos três estádios fenológicos do girassol (vegetativo, floração e formação da produção), correspondendo à ocorrência de déficit hídrico em um, dois ou três estádios. O déficit correspondeu à aplicação da metade da lâmina de irrigação do tratamento sem déficit hídrico. Foram procedidos todos os tratos culturais e fitossanitários necessários. Para se mensurar os efeitos dos tratamentos foram avaliadas ao término de cada estádio fenológico às seguintes variáveis: temperatura foliar, taxas de fotossíntese, transpiração, condutância estomática, concentração interna de CO2, eficiências instantâneas e intrínsecas de uso da água, altura da planta, número de folhas, diâmetro do caule, área foliar, produção de fitomassa seca dos constituintes da parte aérea (caule, folha, pecíolo e capítulo) e a participação de cada um deles em relação à produção de fitomassa seca total (partição). Por ocasião da colheita, avaliaram-se os componentes de produção (diâmetro do capítulo, massa de 1.000 aquênios e os teores de óleo e de proteínas), os rendimentos potenciais de produção de aquênios, óleo e proteínas, e os índices de eficiência de uso da água em produzir aquênios, óleo e proteínas. As variáveis foram submetidas à análise estatística realizando-se análise de variância (Teste F) e Teste de Tukey para comparação de médias. Determinaram-se, ainda, os coeficientes de sensibilidade ao déficit hídrico (KY) nos estádios isolados e no ciclo total da cultura, através da relação entre a queda de rendimento relativo e o déficit de evapotranspiração relativa. Os resultados mostraram que a temperatura foliar e as trocas gasosas, não mostraram efeitos do nível déficit hídrico avaliado, independentemente da época em que os mesmos foram aplicados. As épocas de avaliação influenciaram todas as variáveis relacionadas às trocas gasosas, com exceção da eficiência intrínseca de uso da água. A altura da planta, o número de folhas e o diâmetro do caule foram negativamente afetados pelos efeitos isolados dos déficits de irrigação e das épocas de avaliação. Os déficits de irrigação e as épocas de avaliação interagiram e afetaram a área foliar, a massa seca da folha, do pecíolo, do caule, do capítulo e a total. Os déficits de irrigação não modificaram a partição de fitomassa. Foram observadas modificações no diâmetro dos capítulos, na massa de mil aquênios, no teor de óleo dos aquênios, no potencial de produção de aquênios, óleo e proteína, e na eficiência de uso da água na produção de aquênios e óleo nos déficits hídricos aplicados. A estratégia de manejo da irrigação com déficit durante os estádios vegetativo e de floração do girassol contribuiu para a obtenção de um potencial de produção de aquênios na cultura em um nível equiparado ao alcançado no cultivo sem déficit hídrico durante toda a estação de crescimento. Independentemente da fase fenológica, o déficit hídrico exerceu efeito benéfico na eficiência de uso da água na produção de aquênios. A incidência de déficit hídrico durante o estádio de floração foi mais vantajosa para a eficiência de uso da água na produção de óleo, do que em qualquer outra fase, e não influenciou a eficiência de uso da água na produção de proteína, independentemente da etapa fenológica em que esse ocorreu. A sensibilidade ao déficit hídrico, quantificada mediante o coeficiente de sensibilidade ao déficit hídrico (KY) variou na seguinte ordem decrescente: formação da produção, vegetativo e floração, para déficit aplicado em apenas um estádio fenológico. Para as condições de déficit em dois estádios, o coeficiente KY indicou que a insuficiência de água exerce maior impacto sobre o rendimento de aquênios do girassol quando ocorre simultaneamente nos estádios vegetativo e de formação da produção. Como os valores de KY foram inferiores a 1 em todos os estádios, conclui-se que a cultura demonstrou uma baixa sensibilidade aos déficits hídricos aplicados, mostrando-se, portanto, adaptável à prática da irrigação com déficit durante todo o seu ciclo.
73

A CITY REVITALIZED: PROMOTING CIVIC PRESENCE TO REESTABLISH IDENTITY

SMITH, KANDICE K. 03 October 2006 (has links)
No description available.
74

A Position Paper of Environmental Education for Nelson County

Hunt, Geneva B. 01 August 1974 (has links)
The results of a survey, concerning environmental education taken of the educators of the Nelson County School System, indicated a need for environmental education workshops and classes. The status of environmental education in the nation and in Kentucky were studied and compared. A research was done of the status of environmental education in Nelson County, and implications were drawn for implementing environmental education in the Nelson County School System. A tentative program for implementing environmental education in the Nelson Country schools was given, and a bibliography of resources and materials to be used in said program was included.
75

Quantile regression in risk calibration

Chao, Shih-Kang 05 June 2015 (has links)
Die Quantilsregression untersucht die Quantilfunktion QY |X (τ ), sodass ∀τ ∈ (0, 1), FY |X [QY |X (τ )] = τ erfu ̈llt ist, wobei FY |X die bedingte Verteilungsfunktion von Y gegeben X ist. Die Quantilsregression ermo ̈glicht eine genauere Betrachtung der bedingten Verteilung u ̈ber die bedingten Momente hinaus. Diese Technik ist in vielerlei Hinsicht nu ̈tzlich: beispielsweise fu ̈r das Risikomaß Value-at-Risk (VaR), welches nach dem Basler Akkord (2011) von allen Banken angegeben werden muss, fu ̈r ”Quantil treatment-effects” und die ”bedingte stochastische Dominanz (CSD)”, welches wirtschaftliche Konzepte zur Messung der Effektivit ̈at einer Regierungspoli- tik oder einer medizinischen Behandlung sind. Die Entwicklung eines Verfahrens zur Quantilsregression stellt jedoch eine gro ̈ßere Herausforderung dar, als die Regression zur Mitte. Allgemeine Regressionsprobleme und M-Scha ̈tzer erfordern einen versierten Umgang und es muss sich mit nicht- glatten Verlustfunktionen besch ̈aftigt werden. Kapitel 2 behandelt den Einsatz der Quantilsregression im empirischen Risikomanagement w ̈ahrend einer Finanzkrise. Kapitel 3 und 4 befassen sich mit dem Problem der h ̈oheren Dimensionalit ̈at und nichtparametrischen Techniken der Quantilsregression. / Quantile regression studies the conditional quantile function QY|X(τ) on X at level τ which satisfies FY |X QY |X (τ ) = τ , where FY |X is the conditional CDF of Y given X, ∀τ ∈ (0,1). Quantile regression allows for a closer inspection of the conditional distribution beyond the conditional moments. This technique is par- ticularly useful in, for example, the Value-at-Risk (VaR) which the Basel accords (2011) require all banks to report, or the ”quantile treatment effect” and ”condi- tional stochastic dominance (CSD)” which are economic concepts in measuring the effectiveness of a government policy or a medical treatment. Given its value of applicability, to develop the technique of quantile regression is, however, more challenging than mean regression. It is necessary to be adept with general regression problems and M-estimators; additionally one needs to deal with non-smooth loss functions. In this dissertation, chapter 2 is devoted to empirical risk management during financial crises using quantile regression. Chapter 3 and 4 address the issue of high-dimensionality and the nonparametric technique of quantile regression.
76

Riding Red Ink: Public Ownership of Mass Transit in Indianapolis

Wilhite, Ryan Daniel January 2011 (has links)
**Note** During the research process, IndyGo donated some of the resources cited within this paper to the Indiana Historical Society. That collection has not been archived yet. Further, IndyGo may have placed other documents (created during the time of public ownership) in the Indiana State Archives or the Indiana State Library. / Indiana University-Purdue University Indianapolis (IUPUI) / Today, most urban mass transit providers are publicly owned. Just a few decades ago, and for a majority of the history of mass transit, private owners provided transportation for communities. The decline of private ownership in Indianapolis resulted in transit crisis that pitted private owners against local government, riders and community groups. Advocates lambasted the private owners for their profit-first tactics, pointing to the dividends gained by the private owners. These owners, the Midland Transportation Corporation, also owned the mass transit companies in Milwaukee, Wisconsin and Louisville, Kentucky. Indianapolis politicians, residents and newspapers, all firmly conservative, hoped private owners could continue to operate Indianapolis Transit Systems without public assistance. The imminent failure prompted a discussion of the future of transportation in the city of Indianapolis. Community groups hoped the new public corporation would increase service for Indianapolis and not continue the skeleton system managed by the private owners. A storm of uncontrollable events prevented the robust expansion of the new public corporation and its lack of funding resulted in a continuing decline of service, much akin to the private owners that were abhorred by transit riders. Public ownership in Indianapolis revealed the importance of public ownership in the historiography of mass transportation and urban history. The regional investigation of Midland Transportation confirmed the notion of transit as a unique industry, both in its industrial relations and influence of the locality. The basic rationale for public ownership in Indianapolis would be the most important: the provision of public transportation for those unable to afford private transportation to obtain necessary services.
77

Uma solução para a equação da energia cinética turbulenta empregando o método das características / A solution for the turbulent kinetic energy equation employing the method of characteristics

Szinvelski, Charles Rogério Paveglio 31 August 2009 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In this study, using the Method of Characteristics and numeric resources, presents a solution to the equation Spectral Density Evolution of Turbulent Kinetic Energy for a Convective Boundary Layer (CBL) in the morning. It presents three models for the evolution of spectral energy density. The first model, based on the assumption of a system of isotropic turbulence, considering only terms of energy transfer inertial and viscous dissipation. The second model adds the term energy production due to the onset of action of the parameter of heat flux on the surface, but consider it a term of energy transfer inertial anisotropy. The third model employs a mixed configuration of the two previous models, assuming thus distinct regions of operation to inertial transfer terms. The results shaped the evolution of the CLC. In this case, the growth of the energy spectrum is modeled by inserting energy in the region of low wave numbers, a region in which the term of anisotropic energy transfer can not transfer the energy introduced by the energy production term. It is observed that in a region of wave number higher there is a stabilization of the parameter variation temporal on the plane characteristics curves (PCC), indicating that the variation of wave number govern the evolution of the energy spectrum. This fact establishes a kind of criterion for stationarity of turbulent flow regimes. / No presente trabalho, utilizando o Método das Característica e recursos numéricos, apresenta-se uma solução para a Equação de Evolução Espectral de Densidade de Energia Cinética Turbulenta para uma Camada Limite Convectiva (CLC) no período da manhã. Apresenta-se três modelos para a evolução espectral da densidade de energia. O primeiro modelo, baseado na suposição de um regime de turbulência isotrópica, considera apenas termos de transferência de energia inercial e de dissipação viscosa. O segundo modelo adiciona o termo de produção de energia devido o início da ação do parâmetro de fluxo de calor na superfície, porém considerá-se um termo de transferência de energia inercial anisotrópico. O terceiro modelo emprega uma configuração mista dos dois modelos anteriores, admitindo, desta forma, regiões distintas de atuação para os termos de transferência inercial. Os resultados obtidos modelaram a evolução da CLC. Neste caso, o crescimento do espectro de energia modelado se deu pela inserção de energia na região de baixos números de onda, região em que o termo de transferência de energia anisotrópico não consegue transferir a energia inserida pelo termo de produção de energia. Observa-se que em uma região de número de onda mais alto existe uma estabilização da variação do parâmetro temporal sobre as curvas características planas (CCP), indicando que a variação do número de onda governará a evolução do espectro de energia. Fato que estabelece um tipo de critério de estacionariedade para de regimes de escoamento turbulento.
78

Microwave interaction in nonlinear metamaterials

Lapine, Mikhail 22 September 2004 (has links)
This Thesis is devoted to theoretical investigation of the effective magnetic properties of nonlinear metamaterials, based on resonant conductive elements.A general expression for the effective bulk ermeability in the microwave frequency range is derived. Frequency dispersion of the permeability is studied and recommendations for optimisation of metamaterials with negative permeability are given. The results are supported with numerical simulation of the finite metamaterial sample.Next, a metamaterial possessing nonlinear magnetic responseowing to nonlinear electronic components, inserted into resonant conductive elements, is proposed. For the limit of low nonlinearity, the arising quadratic nonlinear susceptibility is calculated; it is shown how it is controlled by the properties and arrangement of the structure elements as well as by the type and characteristics of the insertion.For the insertions operating in essentially nonlinear regime, when a nonlinear magnetic susceptibility cannot be introduced, an approach is developed for analyzing three-wave coupling processes with a strong pump wave and two weak signals. Peculiarities of coupling, arising from use the insertions with variable resistance or variable capacitance are discussed. Estimates are given that extremely strong nonlinear coupling can be achieved using typical diodes reported in literature.Finally, it is demonstrated how the metamaterial band gap can be tuned, and the resulting metamaterial switching between transmitting, reflecting and absorbing states is described. The details appear to depend drastically on the type of nonlinear components inserted into the resonant conductive elements. Relying on practical estimates, it is predicted that the transmittance of a metamaterial slab can be modulated by several orders of magnitude already using a slab with thickness equal to one microwave wavelength in vacuum.
79

Vectorial beam coupling in fast photorefractive crystals with AC-enhanced response / Vectorial beam coupling in fast photorefractive crystals with AC-enhanced response

Filippov, Oleg 28 September 2004 (has links)
We develop a theory of vectorial wave coupling in cubic photorefractive crystals placed in an alternating ac-field to enhance the nonlinear response. First we analytically and numerically investigate the dependences of the first Fourier harmonics of the space-charge field, induced in an AC-biased sillenite crystal by a light-interference pattern, on the light contrast m. The data obtained was used to extend the vectorial beam-coupling theory on the whole contrast region. In particular, we proved in the general case that despite of essential differences between thediffusion and AC nonlocal responses the later keeps the light interference fringes straight during the interaction. This fundamental feature allows, under certain restrictions, to reduce the nonlinear problem of vectorial coupling to the known linear problem of vectorial Bragg diffraction from a spatially uniform grating, which admits an exact solution. As a result, the nonlinear vectorial problem can be effectively solved for a number of practically important cases.The developed theory was applied to describe the transformation of a momentary phase changes of one of the input beams into the output intensity modulation (so-called grating translation technique). In contrast to the previous studies, we take into account the change of the space-charge field amplitude across the crystal (the coupling effects). The theory developed is employed to optimize the conditions for the linear signal detection under polarization filtering for the transverse and longitudinal optical configurations. We also analyze the possibility of the linear detection without polarization filtering.Illumination of AC-biased photorefractive BTO crystals with a coherent light beam results in development of strong nonlinear scattering. We investigate the angular and polarization characteristics of the scattered light for the diagonal optical configuration and different polarization states of the pump.
80

Ultrafast Photon Management: The Power of Harmonic Nanocrystals in Nonlinear Spectroscopy and Beyond

Kijatkin, Christian 01 April 2019 (has links)
The present work broaches the physics of light-matter interaction, chiefly using nonlinear optical spectroscopy in a newly developed framework termed as Photon Management Concept. This way, existing fragments dealing with specific properties of harmonic and upconversion nanoparticles (HNPs/UCNPs) are consolidated into a full and coherent picture with the primary goal of understanding the underlying physical processes and their impact on the application side, especially in terms of imaging techniques, via suitable experimental and numerical studies. Contemporary optical setups involving contrast-enhancing agents are frequently limited in their excitation and detection configurations owing to a specialization to a select number of markers. As a result, the bandwidth of experimental methods and specimens that may be investigated is severely restricted in a large number of state-of-the-art setups. Here, an alternative approach involving HNPs and UCNPs, respectively, is presented providing an overview from their synthesis to optical characterization and to potential fields of application. Based on their inherent flexibility based on their nonlinear optical response, especially in terms of wavelength and intensity tunability, the PMC alleviates prevalent limitations by dynamically adapting the setup to a sample instead of the preliminary culling to a reduced number of eligible specimens that must not change their optical properties significantly during investigation. The use of HNPs supersedes such concerns due to their nearly instantaneously generated, strongly anti-Stokes shifted, coherent emission capable of producing radiation throughout the visible spectral range, including infrared and ultraviolet wavelengths. This way, HNPs transcend the traditional field of imaging and introduces potential applications in optomanipulation or holographic techniques. Thorough (nonlinear) optical characterization of UCNPs and alkali niobate HNP ensembles is performed to assess the fundamental physical mechanisms interwoven with numerical studies leading to their wide-ranging applicability. Final remarks show that HNPs are ideal candidates for realization of the PMC and yet hold an even further potential beyond current prospects.

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