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The Effect of a Senolytic Drug on Messenger RNA and Micro RNA Expression in Perigonadal Adipose Tissue of Young and Old MiceHernandez, Catalina 01 January 2020 (has links) (PDF)
As we face an expanding elderly population and increased age-related chronic diseases, we must seek solutions that address interconnected problems. Dasatinib plus quercetin (D+Q), a novel combination drug, is a proposed solution to improve the health and longevity of aged individuals with minimal side effects, exceptional efficacy, and maximum convenience. In this experiment, intermittent D+Q treatment was completed on young and old mice. RNA was extracted from perigonadal adipose tissue and cDNA libraries of mRNA and miRNA were made. Real-time quantitative polymerase chain reaction was used to assess relative gene expression for mRNA and miRNA pertaining to cell senescence, inflammation, and insulin resistance. miR-146a was found to have a significant difference (p < 0.05) in relative expression based on the interaction between age and treatment, while other genes showed no difference in relative expression. Furthermore, miR-149 was found to show near significance in interaction (p=0.0552) and had significant difference between old control and old D+Q treated mice. The miR-149 presents an avenue for future research in senescence markers and shows potential as a novel senolytic target.
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D-q impedance identification in three phase systems using multi-tone perturbationZhou, Bo 31 May 2013 (has links)
In electric power systems, the existence of constant power loads such as output-regulated power converters may bring instability problem to AC or DC distributed systems. Impedance based stability criteria has been proven a good tool for small-signal stability analysis.
This works focuses on the developing of a comprehensive software tool which can extract DC or three phase AC impedances, and apply stability analysis. An algorithm is designed to select FFT window and adjust perturbation frequencies. This feature enables the software to accurately measure impedances even in existence of system line harmonics. Furthermore, multi-tone approach is developed to improve simulation time. The complete software tool is tested with simulation models and experiment results, to show the effectiveness.
When multi-tone approach is applied on nonlinear loads, it gives incorrect results. The reason is that perturbation frequency will have overlapping with side-band harmonics. An algorithm is designed to avoid this problem. The algorithm is tested with 12-pulse diode rectifier simulation model, and 6-pulse diode rectifier simulation model and experimental test bed. Both simulation and experiment results verifies the concept. / Master of Science
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Singularidades do tipo D(q,p) / Singularities of type D(q,p)Carvalho, Rafaela Soares de [UNESP] 31 March 2016 (has links)
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Previous issue date: 2016-03-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Neste trabalho estudamos germes de funções sob a ação do grupo R_I dos germes de difeomorfismos em C^n que preservam um ideal I, descrevendo os conceitos de codimensão e determinação finita associados. Isso nos fornece ferramentas para caracterizar um tipo especial de germes com singularidades não isoladas, as chamadas singularidades do tipo D(q,p). Conseguimos ainda relacionar o conceito de R_I-estabilidade com estes germes, para o caso em que I é um ideal radical que define uma intersecção completa quase homogênea com singularidade isolada. Além disso, apresentamos um
sistema de coordenadas através do qual obtemos uma fórmula explícita para alguns dos números de Lê destes germes. / In this work we study germs of functions under the action of the R_I group of diffeomorphisms of germs in C^n which preserving an ideal I, describing the concepts of codimension and finite determination
associated. This provides the tools to characterize a particular type of germ with non isolated singularities, the so called D(q,p) singularities. We can still relate the concept of R_I-stability with these germs, in the case where I is a radical ideal that defines complete intersection with isolated singularity. Moreover, we present a coordinate system by which we obtain an explicit formula for some Lê numbers of these germs.
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An Algorithm and System for Measuring Impedance in D-Q CoordinatesFrancis, Gerald 10 May 2010 (has links)
This dissertation presents work conducted at the Center for Power Electronics Systems (CPES) at Virginia Polytechnic Institute and State University.
Chapter 1 introduces the concept of impedance measurement, and discusses previous work on this topic. This chapter also addresses issues associated with impedance measurement.
Chapter 2 introduces the analyzer architecture and the proposed algorithm. The algorithm involves locking on to the voltage vector at the point of common coupling between the analyzer and the system via a PLL to establish a D-Q frame. A series of sweeps are performed, injecting at least two independent angles in the D-Q plane, acquiring D- and Q-axis voltages and currents for each axis of injection at the point of interest.
Chapter 3 discusses the analyzer hardware and the criteria for selection. The hardware built ranges from large-scale power level hardware to communication hardware implementing a universal serial bus. An eight-layer PCB was constructed implementing analog signal conditioning and conversion to and from digital signals with high resolution. The PCB interfaces with the existing Universal Controller hardware.
Chapter 4 discusses the analyzer software. Software was written in C++, VHDL, and Matlab to implement the measurement process. This chapter also provides a description of the software architecture and individual components.
Chapter 5 discusses the application of the analyzer to various examples. A dynamic model of the analyzer is constructed, considering all components of the measurement system. Congruence with predicted results is demonstrated for three-phase balanced linear impedance networks, which can be directly derived based on stationary impedance measurements. Other impedances measured include a voltage source inverter, Vienna rectifier, six-pulse rectifier and an autotransformer-rectifier unit. / Ph. D.
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Output Impedance Modeling and Measurement of a 28 kW Synchronous GeneratorShan, Keyue 09 June 2022 (has links)
Synchronous machines (SMs) are a vital part of today's world, and precise modeling is important for studying their stability. In this thesis, a small-signal analysis is done on the d-q frame for the AC SM. Starting from formulating the SM's abc frame equations, a d-q transformation is done based on the SM rotor frame so that the inductance from the abc frame representation will be fixed. Then, the SM's fundamental parameters are obtained from standstill frequency response testing. In the interest of having the most complete model possible, a governor controller and an exciter controller have been designed, and their performance has been evaluated according to the International Standard ISO-8628. A d-q steady-state analysis has been carried out and the resulting small-signal perturbation has been added to the steady-state equations. The model has been analyzed with exciter control only, with governor control only, and with both controllers, and in the end, the small-signal d-q impedance model for the SM has been verified by simulations and experiments in the Center for Electronics Systems (CPES) at Virginia Tech. The impedance measurement unit (IMU) was built by CPES. It is designed for measuring three-phase AC power systems and DC systems. Nevertheless, even though the single-phase system can be connected to the IMU, the impedance result in the end is not correct. Modifications have been made to the IMU so that it is able to calculate the single-phase AC power system impedance. The experimental results demonstrate that implementation has been completed. / Master of Science / Emergency diesel generators are critical in the event of widespread blackouts. Generators are typically synchronous machines (SMs), and stability studies are crucial from the standpoint of the power system. With knowledge gained through stability analysis, if instability occurs, a solution can be quickly formulated based on phenomena that has been observed during the event. In order to study the system stability, an accurate model is essential. The small-signal d-q impedance model will be derived by the Center for Power Electronics Systems (CPES) at Virginia Tech based on an AC generator that is rated at 28 kW, and the impedance results will be verified by both MATLAB/Simulink simulations and experiments. The impedance measurement unit (IMU) will serve as the equipment to do the measurement. However, the IMU can only correctly calculate impedance for a three-phase power system. For the single-phase AC power system, due to the three-phase phase locker loop (PLL) calculating the wrong angle, the IMU cannot properly determine the impedance. However, modifications have been applied to the IMU so that it can automatically calculate the impedance for a single-phase AC power system.
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The Quarrel of the Fairies: The Tales of Mme D'Aulnoy and PerraultGoodridge, Elisabeth S. January 2008 (has links) (PDF)
No description available.
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[en] USING LINEAR AND NON-LINEAR APPROACHES TO MODEL THE BRAZILIAN ELECTRICITY SPOT PRICE SERIES / [pt] MODELOS LINEARES E NÃO LINEARES NA MODELAGEM DO PREÇO SPOT DE ENERGIA ELÉTRICA DO BRASILLUIZ FELIPE MOREIRA DO AMARAL 17 July 2003 (has links)
[pt] Nesta dissertação, estratégias de modelagem são
apresentadas envolvendo modelos de séries temporais
lineares e não lineares para modelar a série do preço
spot no mercado elétrico brasileiro. Foram usados, dentre
os lineares, os modelos ARIMA(p,d,q) proposto por Box,
Jenkins e Reinsel (1994) e os modelos de regressão
dinâmica. Dentre os não lineares, o modelo escolhido foi o
STAR desenvolvido, inicialmente, por Chan e Tong (1986) e,
posteriormente, por Teräsvista (1994). Para este modelo,
testes do tipo Multiplicador de Lagrange foram usados para
testar linearidade, bem como para avaliar os modelos
estimados. Além disso, foi também utilizada uma proposta
para os valores iniciais do algoritmo de otimização,
desenvolvido por Franses e Dijk (2000). Estimativas do
filtro de Kalman suavizado foram usadas para substituir os
valores da série de preço durante o racionamento de energia
ocorrido no Brasil. / [en] In this dissertation, modeling strategies are presented
involving linear and non-linear time series models to model
the spot price of Brazil s electrical energy market. It has
been used, among the linear models, the modeling approach
of Box, Jenkins and Reinsel (1994) i.e., ARIMA(p,d,q)
models, and dynamic regression. Among the non-linear ones,
the chosen model was the STAR developed, initially,
by Chan and Tong (1986) and, later, by Teräsvirta (1994).
For this model, the Lagrange Multipliers test, to measure
the degree of non linearity of the series , as well as to
evaluate the estimated model was used. Moreover, it was
also used a proposal for the initial values of the
optimization algorithm, developed by Franses and Dijk
(2000). The smoothed Kalman filter estimates were used in
order to provide values for the spot price series during
the energy shortage period.
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Impedance Extraction by MATLAB/Simulink and LabView/MultisimLin, Jen-Pin 17 April 2014 (has links)
This thesis studies the techniques of small-signal impedance measurement in three-phase power systems. Stability issue has become critically important since power electronics are highly applied in power distribution and conversion systems. Controlled output systems cause the risk of instability. In order to obtain the impedance model, an impedance extraction in D-Q reference frame algorithm is developed. This paper also applied Interpolated Fast Fourier Transform to increase accuracy of impedance model. Based on the voltage injection, Phase-Locked Loop, Park Transform, D-Q reference frame, and IPFFT. Three-phase system has been realigned on D-Q coordinate and impedance model is extracted in this form.
Firstly, impedance extraction algorithm is designed by MATLAB/Simulink, the algorithm includes PLL, D-Q transform, and IPFFT is used to obtain magnitude and phase angle in frequency domain. Impedance matrices in D-Q frame may be solved through the relation between currents and voltages. Impedance model is made through various tests. Secondly, using the algorithm to test RL circuit to verify with real bode plot of the circuit. Then apply the algorithm on sophisticated circuit model. Finally, implement the algorithm on LabView/Multisim for future hardware tests.
This paper clearly describes the objective of the research, the research problem and approaches, and experiment setup. This paper presents work conducted at the Smart Grid Power Systems Laboratory at University of South Florida.
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Simulace pohonu hybridního automobilu / Simulation of hybrid car driveByrtus, Jiří January 2013 (has links)
This thesis deals with analysis of electric drive parts from hybrid electric vehicle, namely interior permanent magnet synchronous motor and inverter with control. First part describes a basic theory. Further, motor and inverter computer models are shown, specified simulations are performed on this models. Results are compared with values measured on real machines from accessible literary sources.
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