Dissertations / Theses on the topic 'Experimental analysis'

Many problems in science and engineering are solved through experimental investigations. Because experiments can be costly and time consuming, it is important to efficiently design the experiment so that maximum information about the problem can be obtained. It is also important to devise efficient statistical methods to analyze the experimental data so that none of the information is lost. This thesis makes contributions on several aspects in the field of design and analysis of experiments. It consists of two parts. The first part focuses on physical experiments, and the second part on computer experiments. The first part on physical experiments contains three works. The first work develops Bayesian experimental designs for robustness studies, which can be applied in industries for quality improvement. The existing methods rely on modifying effect hierarchy principle to give more importance to control-by-noise interactions, which can violate the true effect order of a system because the order should not depend on the objective of an experiment. The proposed Bayesian approach uses a prior distribution to capture the effect hierarchy property and then uses an optimal design criterion to satisfy the robustness objectives. The second work extends the above Bayesian approach to blocked experimental designs. The third work proposes a new modeling and design strategy for mixture-of-mixtures experiments and applies it in the optimization of Pringles potato crisps. The proposed model substantially reduces the number of parameters in the existing multiple-Scheffé model and thus, helps the engineers to design much smaller experiments. The second part on computer experiments introduces two new methods for analyzing the data. The first is an interpolation method called regression-based inverse distance weighting (RIDW) method, which is shown to overcome some of the computational and numerical problems associated with kriging, particularly in dealing with large data and/or high dimensional problems. In the second work, we introduce a general nonparametric regression method, called kernel sum regression. More importantly, we make an interesting discovery by showing that a particular form of this regression method becomes an interpolation method, which can be used to analyze computer experiments with deterministic outputs.

Experimental study was conducted to analyze the physical flow turbulence and sediment distribution with submerged vane. The objectives behind the investigation were verified and compare results with the Odgaard theory, also; achieved to measure vertical pressures acting on both sides of submerged vane, calculate lift and drag forces, lift and drag coefficients experimentally, that the theory of Odgaard was fails to predict satisfactorily. Other motivation of the study was investigates experimentally the hydrodynamic characterization of submerged vanes as; velocities fields, circulation, vorticity, bed topography, pressures, drag and lift forces with its coefficients, study physical fluid turbulence of submerged vanes as; Reynolds normal and shear stresses, turbulent kinetic energy and rate of dissipation, turbulence intensities, Kolmogorov scales, kinetic energy spectrum, turbulent velocities fields, fluctuating velocities and finally Reynolds stresses histograms. Tests were conducted with clear water was transported throughout the re-circulated rectangular channel with cross-section 7.5 m long, 2.52 m wide channel with a bed consisting of 50 cm thick layer of sand with a median diameter of 1.6-mm and a geometric standard deviation of 1.36. Velocities were measured with a 7 Acoustic Doppler Velocimeter ADV, which were calibrated and checked periodically, depths and water surface elevations were measured with a gauge that could be read with an error of less than 0.3 mm. The current meter, gauges were mounted on a movable instrument sliding carriage, which rode on rails a top of the channel walls, on a traversing mechanism, which enabled them to be positioned at any desired location in the channel. Positioning and data sampling were controlled from a computer program. The water surface elevations were used to determine water surface slope S and Darcy-Weisbach friction factor f=8gRS/u_o^2, where uo = undisturbed (pre-vane) cross-sectional-averaged velocity. In all tests, uo=0.2867 m/s, and the discharge Q=116,62 l/s =0.11662 m^3/s. The vanes were made of 14 mm-thick PVC sheet, they were rectangular in shape, with height H = 7 cm = 0.4337d, and length L = 25 cm = 3.571H. In all tests, the vanes were placed at an angle of attack of 20 degrees with the channel centerline. Water depth was 0.1614 m, pre-vane water surface slope, friction factor and geometric standard deviation, sg, were 1.6×10^(-3), 0.045 and 1.36 respectively. The Vectrinos were been calibrated to work at 25Hz and for each position taken data for 4 minutes, a sample volume that is located approximately 4.3 mm of the device. For each position there are seven Vectrinos 10 cm distance from one to other taking data, so data recorded 7 points at the same time. Data recorded were taking on about 24.080 points on whole the sectional cross channel, with the aim to measure the velocities once the channel-bed has reached to the permanent regime or steady state (equilibrium), during the measurements of velocities, we has taken the bed topography (bathymetry) of the channel-bed by using ADV. In the current dissertation, we installed 30 piezometers in each side of Vane. Once obtained the experimental pressures measured at the laboratory on both sides of vane, the pressure difference between vane sides (¿P), and the perpendicular resultant force (FR¿) acting on the vane, first calculated the resultant force between drag and lift components (FR), then we used this force to calculate drag force FD and lift force FL, also calculated Drag coefficient CD, and finally we calculated the Lift coefficient CL. Results, includes submerged vanes turbulence statistics as; Probability distribution of the velocity field, Reynolds stresses, Turbulence intensity, Kinetic and Dissipation energy, and finally, Kolmogorov turbulence scales. Other results contain energy spectrum, turbulent velocities fields, fluctuating velocities and Reynolds stresses histograms.
El estudio experimental se ha llevado a cabo para analizar el funcionamiento, la turbulencia del flujo y el transporte de sedimentos con paneles sumergidos. Los objetivos tras la investigación fueron verificados y comparados con los resultados de la teoría de Odgaard, también; se han medido las presiones verticales que actúan sobre ambos lados de los paneles sumergidos, se han calculado las fuerzas de drag y lift y, sus coeficientes experimentalmente, ya que la teoría de Odgaard no pudo predecirlas satisfactoriamente. Otra motivación del estudio, fue investigar experimentalmente la caracterización hidrodinámica de los paneles sumergidos como; distribución de velocidades, circulación, vorticidad, topografía del fondo, presiones, fuerzas de drag y lift y sus coeficientes, tensiones de Reynolds, energía cinética turbulenta y disipación turbulenta, intensidades de turbulencia, escalas de Kolmogorov, espectro de energía cinética, campos de velocidades turbulentas, velocidades fluctuantes y finalmente, histogramas de las tensiones de Reynolds. Se realizaron pruebas en aguas claras, a lo largo de un canal rectangular con una sección de 7.5 m de largo, 2.52 m de ancho y un espesor de 50 cm de arena de 1.6 mm de diámetro medio y una desviación geométrica de 1.36. Las velocidades fueron medidas con 7 Acoustic Doppler velocímeter ADV, las que fueron calibradas y revisadas periódicamente, las profundidades y las alturas de superficie de agua fueron medidas con un limnímetro que puede leerse con un error de menos de 0.3 mm. Los paneles fueron construidos con placas de PVC de 14 mm de espesor, de forma rectangular, con altura H = 7 cm = 0.4337d y longitud L = 25 cm = 3.571H. En todos los ensayos, los paneles se colocaron con un ángulo de ataque al flujo de 20 grados con la línea central del canal. El calado del agua es de 0.1614 m, la pendiente superficie, el factor de fricción y la desviación geométrica, fueron, 0.045 y 1.36 respectivamente. Los Vectrinos se han calibrado para trabajar a 25Hz y con un volumen de control de 4.3 mm, para cada posición se tomaron datos durante 4 minutos. Para cada posición hay siete Vectrinos con una distancia de 10 cm entre ellos, registrando por lo tanto 7 puntos al mismo tiempo. Los datos registrados fueron alrededor de 24,080 puntos en toda la sección del canal, con el objetivo de medir las velocidades una vez los sedimentos en el canal han alcanzado el régimen permanente o estacionario (equilibrio), durante las mediciones de las velocidades, se ha medido la topografía del fondo (batimetría) mediante el uso de los sensores ADV. La tesis actual, ha desarrollado un sistema para medir la presión vertical que actúa sobre ambas caras del panel, se instalaron 30 piezómetros de plástico en cada lado del panel. Una vez obtenida la presión experimental medida en el laboratorio a ambos lados del panel, se halla la diferencia de presión entre los dos lados, y la fuerza perpendicular resultante actuando sobre el panel, primero se calculó la fuerza resultante entre los dos componentes de drag y lift, para utilizarla después en el cálculo de la fuerza del drag FD y lift FL, así como el coeficiente de arrastre CD, y finalmente se calculó el coeficiente de lift CL. Los resultados de turbulencia incluyen; Distribución de probabilidad de la distribución de velocidades, tensiones de Reynolds, intensidad turbulenta, energía cinética y disipación. Finalmente, escalas de turbulencia de Kolmogorov. Otros resultados contienen el espectro de energía, campos de velocidades turbulentas, velocidades fluctuantes y los histogramas de las tensiones de Reynolds.

Thesis (M.S.)--West Virginia University, 2009.
Title from document title page. Document formatted into pages; contains vi, 68 p. : ill. Includes abstract. Includes bibliographical references (p. 56-58).

The diploma thesis deals with analysis of risks in relation to various focus (or types) of economic experiments. On the basis of background research suggests entirely new classification of economic experiments and subsequently examines general structure of economic experiment. Performed analysis then identifies major risks of experimental economics, analyses them and proposes possible countermeasures. Outputs of the work substantially enrich and extend current theory. Their utilization is expected in theory and practice, for purpose of scientific research or specific objectives of companies and institutions.

Indentation tests are widely used with simultaneous measurements of indentation depth and force especially for determining material properties. In this study
numerical and experimental investigation of the force-indentation measurements is presented. For indentation tests on anisotropic metals, a novel indenter which is not self similar is used with three transducers to measure the displacements. It is seen that in order to have high repeatability and accuracy at the tests, workpiece and indenter parameters have crucial importance. These parameters in the indentations are analyzed by finite element methods. Ideal dimensions of the workpiece are determined. It is shown that plane strain conditions can only be achieved by embedded indentations. Effect of surface quality and clamping on repeatability are investigated. It is shown that surface treatments have significant effects on the results. Also it is seen that clamping increases the repeatability drastically. Moreover, indentation tests are conducted to verify the results of numerical simulations. Effect of anisotropy on the force-displacement curves is clearly observed.

ABSTRACT EXPERIMENTAL ANALYSIS OF CURVED LAMINATED GLASS BEAM Uzhan, Tevfik M.S., Department of Engineering Sciences Supervisor: Prof. Dr. M. Zü
lfü
ASik May 2010, 33 Pages In this thesis, experimental studies are carried out on curved laminated glass beams to form a database for the scientists who may like to test their mathematical models. Beams which are only free to rotate and constrained in radial direction at both ends are tested to make the data available for further calculations. Test setup is prepared to minimize error that could occur due to test setup and data readings. Material testing machine and 4 channel data collecting machine are used to measure the signals at the strain gauges located over the glass beam. Within the range of force applied to the specimens, laminated curved beam shows linear behavior without any fracture. Data collected from the specimens are in conformance with each other. Results obtained from experiments are compared with the results obtained from the mathematical model developed by ASik and Dural (2006). As it is observed from the graphs presented, experimental results from the tests and numerical results from the mathematical model are in good agreement.

Studying a subject is central to understanding its behavior and what it has learned. In this thesis, we study specific aspects of five representation learning systems for natural language processing tasks. Representation learning systems are a type of machine learning system dedicated to learn representations of data suitable for other machine learning systems, such as classifiers, to operate upon them. Thus, understanding the behavior of and the abilities learned by representation learning systems is crucial for improving the results on the tasks they are used. The aspects on which we focus are interpretability, robustness, and abilities learned. We are interested in obtaining explanations that allow us to understand how a system makes a decision, what factors from the data and internal to the system affect its robustness, and to what extent it has learned a linguistic ability. To do so, we propose to carry out three types of analyses, namely functional, behavioral, and internal analyses which we link with work on the cognitive science, behavioral science, and neuroscience. We present three case studies. In the first study, we provide a functional explanation of a matrix factorization system that allow us to understand how this system makes a prediction. In our second study, we investigate how robust are three systems when the input data suffers a simple transformation and how certain external and internal factors influence their behavior; these systems are trained for the task of natural language inference. Finally, our third study shows that we are able to extract hypernymy from the word embeddings of a popular ReLe system, while studying the influence that the choice of hypernymy dataset plays in the task. In summary, we advance towards better understanding ReLe systems by providing explanations of their predictive behavior and investigating abilities learned by these systems.

Drug solubility and dissolution are important attributes controlling the bioavailability (BA) of oral dosage forms and can be determined in vivo, however it is expensive and can generate ethical issues. In vitro tests have been introduced utilising simulated gastrointestinal (GI) fluids, capturing the GI composition and conditions. However, individual variation and food-induced changes of the GI environment affecting drug BA have been recognised and in-depth knowledge is required to understand their effects on drug absorption. A fractional factorial design of experiment (DoE) and a 4-component mixture design (4MD) were used to investigate drug equilibrium solubility in media presenting in different levels of pH, concentration of amphiphiles, buffer, salt and pancreatin. Poorly soluble acidic, basic and neutral drugs with various physiochemical properties were tested. Solubility results correlate well with literature values, indicating they explored the solubility variation in the biorelevant space. Except pancreatin, all factors showed significant impacts on drug solubility. The descending order of average effect magnitude is pH, amphiphiles, buffer and salt, some of which also displayed remarkable drug specific interactions. Changing amphiphile ratios in 4MD further indicated that solubilisation is not a simple accumulative solubilisation of individual amphiphiles, but interactions between amphiphile-amphiphile and drug-amphiphiles. Powder dissolution using various biorelevant media indicates intrinsic dissolution rates (IDR) are positively correlated with equilibrium solubility and the diffusion coefficient of drugs in different ionisation states and interactions with amphiphiles. The above studies illustrate the convoluted nature of the GI fluids and provide a visualisation of how solubility/dissolution map varies within the ranges of GI fluid parameters. Statistical approaches can systematically detect critical factors affecting drug solubility and dissolution, and the output can potentially be applied in physiologically based pharmacokinetic (PBPK) model to achieve better in vivo-in vitro correlation (IVIVC).

Una millor comprensió dels complexos fenòmens que regeixen la dinàmica del fluxos tri-fàsics així com un increment en la capacitat predictiva de la seva dinàmica, són crucials en el disseny i construcció de sistemes fluidics d'interès per a una àmplia gama d'indústries. Aquest treball de recerca presenta el disseny i muntatge de LESLIE, un circuit tancat de baixa pressió destinat a la recerca en la dinàmica de fluxos bifàsics i trifàsics a través de canonades i els seus accessoris. LESLIE està pensat per obtenir mesures de paràmetres clau i caracteritzar fluxos multifàsics amb fases gasoses, líquides i sòlides, tant en canonades horitzontals com verticals. Presentem aquí noves dades experimentals per a règims intermitents en fluxos bifàsics i trifàsics en configuració horitzontal amb aire, aigua i partícules de polipropilè amb mides d'entre 1 i 2 mil·límetres. Visualitzacions del flux, mesures de pressió i fracció de buit s'han obtingut per a diferents condicions d'operació. En aquest treball investiguem l'impacte de la presència de partícules sòlides sobre la caiguda de pressió, el règim de flux i la freqüència del "slug". A més, l'anàlisi del comportament de fluxos bifàsics anulars mitjançant tècniques de processat d'imatges ha permès obtenir resultats sobre la distribució de mida de gotes.
La dinámica de los flujos trifásicos se rige por fenómenos de alta complejidad, tanto conceptual como matemática. Una mejor comprensión así como un incremento en la capacidad de predicción de su dinámica, son cruciales para el diseño y construcción de instalaciones de interés para una amplia gama de industrias. Este trabajo de investigación presenta el diseño y montaje de LESLIE, un circuito cerrado de baja presión destinado a la investigación experimental de la dinámica de flujos bifásicos y trifásicos a través de tuberías y sus accesorios. LESLIE está pensado para obtener medidas de parámetros clave y caracterizar flujos multifásicos con fases gaseosas, líquidas y sólidas, tanto en tuberías horizontales como verticales.Presentamos aquí nuevos datos experimentales para regímenes intermitentes en flujos bifásicos y trifásicos en configuración horizontal usando aire, agua y partículas de polipropileno con tamaños de entre 1 y 2 milímetros. Visualizaciones del flujo, medidas de presión y fracción de vacío se han obtenido para diferentes condiciones de operación de flujos intermitentes. En este trabajo investigamos el impacto de la presencia de partículas sólidas sobre la caída de presión, el régimen de flujo y la frecuencia del "slug". Además, el análisis del comportamiento de flujos bifásicos anulares mediante técnicas de procesado de imágenes ha permitido obtener resultados sobre la distribución de tamaño de partícula, las cuales también se presentan en este trabajo.
The dynamics of three-phase flows involve phenomena of high complexity, whose understanding and an enhanced prediction capacity of fluid dynamics in multiphase flow systems is crucial for the design and construction of facilities meant for a wide range of industries. This research work presents the design and set up of LESLIE, a low pressure multiphase flow loop for the experimental analysis of two and three-phase flows through pipelines and their accessories. It is designed to measure key parameters, so as to characterise the behaviour of multiphase flows involving gas, liquid and solid phases both in horizontal and vertical pipelines. New experimental data is presented in this study for intermittent two and three-phase flows in horizontal pipelines involving air, water and polypropylene pellets of sizes ranging between 1 and 2 millimetres. Flow visualization, pressure and void fraction measurements were performed and are explored in this work for the case of intermittent flows for a variety of settings. The influence of solid particles over the frictional pressure drop, flow regime and slug frequency is reported in this work. Furthermore, the analysis of the dynamics of annular two-phase flows by means of image processing techniques has allowed obtaining droplet size distributions, which are also presented in this study.

The main aim of this thesis is to investigate the mechanical properties of a hybrid composite material under static loadings. The material is a composite laminate made by layers of carbon bars and a rubber layer. The thesis can be split into three main parts. In the first part a background about carbon bar composite is given and, subsequently, the research and main results on hybrid composites is introduced. The objective of this section is to provide a base on which built the main results of this work. In the second part it is explained how the test activities have been performed and the main results obtained. In particular, the effect of the introduction of a rubber layer has been highlighted in each type of tests. In the last part, a finite element dynamical analysis is presented. A very simple transient analysis has been performed in order to foresee the dynamic behaviour of the hybrid. In conclusion, it has been demonstrated a relevant hybrid effect in the compressive and flexural properties. Those effects can be roughly reassumed in anincreasing specific stiffness for the compressive properties and in a large improvement of flexibility in the bending test. The numerical simulation shows that an increased damping effect is present, corresponding to an increase of rubber layer thickness.

Indentation is a practical and easy method, therefore, is a preferred method of material characterization. Main aim of this thesis study is to determine anisotropic properties of metals by indentation tests. The basic property of the indenter used in the finite element analyses and experiments is that it is specific to this process. Thesis includes studies on optimization of the indenter geometry, analyses of effects of friction coefficient, multiple indentations, tilting of the indenter and clamping of the specimen on force-displacements curves during indentation by finite element analyses. This study also includes finite element analyses of compression tests where these experiments have been necessary to prove anisotropic behavior of the specimen material. In addition to compression, tension tests are done to have a reference for indentation tests. On the other hand, the upper bound method which is an analytical solution is applied on the assumption of plane strain indentation.

Compressed air is widely used particularly in industry. In order to increase the quality of the process and lifetime of the machine, the compressed air should be dried. Therefore the air is used after compression and drying processes. The most commonly used machines that do this process are called &ldquo
Refrigerant Air Dryers&rdquo
. These air dryers are designed to cool and dehumidify the moist air. The process of decreasing temperature is carried out by a refrigerant, R134a. Unlike design conditions, dryers are working in variable loads (variable compressed air flow rates). An experimental setup is prepared for analyzing the variance on the machine and the performance under these variable loads. This thesis includes the design, preparation and the modification of the refrigeration experimental setup for refrigerant air dryers. The setup is tested under three different conditions and the results are compared.

Laminar burning velocity is very useful for both combustion modeling and kinetic scheme validationand improvement. Accurate experimental data are needed. To achieve this, the spherical flame method was chosen. However various expression for burning velocity from the spherically expanding flame can be found. A theorical review details all the expressions and models for the burning veolcity and shows how they can be obtained experimentally. These models were comparated considering basic fuels - various Lewis numbers. As a result, it is shown that the pure kinematic measurement method is the only one thet does not introduce any assumptions. This kinematic measurement had needed the development and validation of an original post-processing tool. Following the theorical review, a parametric experimental study is presented. The new technique is extended to extract burning velocity and Markstein length relative to the fresh gas for pure ethanol, isooctane and blended fuels at high pressure.

Approved for public release; distribution unlimited.
A new design for non-self integrating magnetic-loop sensors (B-dots) has been developed at Los Alamos National Laboratory. Experiments and tests were performed using the Relativistic Electron Beam Experiment (REX) machine to compare the B-dot sensors to optical beam diagnostics (streak camera). the B- dots were assessed to have the capability of measuring the REX electron beam's position to within 0.25mm with 2 percent error, and its transverse oscillatory movement to within 0.5mm amplitude with 7 percent error, over a 1 GHz bandwidth. Many calibration parameters and factors affecting sensor signals were examined during the experiment. The experimental calibration of the B-dots, and the resulting certified accuracy of their remote, non-intrusive measurements of relativistic electron beam parameters should have a wide range of application to many other electron beam machines.

The thesis consists of three chapters with Chapters 2 and 3 providing experimental evidence on the role of cheap-talk and a third party recommendation in reducing or aggravating conflict. Chapter 1 surveys the theoretical, empirical and experimental literature on the determinants of conflict. Chapter 2 considers an experiment based on Baliga and Sjostrom (BS, 2004) to investigate whether communication reduces the probability of an arms race. We find that communication does indeed reduce the possibility of using strategies that lead to an arms race, even when the unique Bayesian Nash equilibrium without communication has both players playing a strategy that leads to an arms race. Chapter 3 considers a set of experiments based on Baliga and Sjostrom (BS, 2012) to understand if third parties can provoke conflict. We adapt their model to experimentally test if a third party recommendation can trigger conflict. While in some treatments with recommendation, more players do choose an aggressive strategy compared to the treatment without, none of them are statistically significant. We propose a number of explanations for why provocation may not necessarily increase conflict in this environment.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biology, 2005.
Includes bibliographical references.
MicroRNAs (miRNAs) are small, endogenous, non-coding RNAs that mediate gene regulation in plants and animals. We demonstrated that Arabidopsis thaliana miRNAs are highly complementary (0-3 mispairs in an ungapped alignment) to more mRNAs than would be expected by chance. These mRNAs are therefore putative regulatory targets of their complementary miRNAs. Many miRNA complementary sites are conserved to the monocot Oryza sativa (rice), implying evolutionary conservation based on function at the nucleotide level. The majority of predicted miRNA targets encode for transcription factors and other proteins with known or inferred roles in developmental patterning, implying that the miRNAs themselves are high-level regulators of development. Our findings indicated that miRNAs are key components of numerous regulatory circuits in plants and set the stage for numerous additional experiments to investigate in depth the significance of miRNA-mediated regulation for particular target families and genes. We developed a comparative genomics approach to identify miRNAs and miRNA targets conserved between Arabidopsis and Oryza. Seven previously unknown miRNAs families were experimentally verified, bringing the total number of known miRNA genes in Arabidopsis to 92, representing 22 families. We expanded the range of functionalities known to be regulated by miRNAs to include F-box proteins, laccases, superoxide dismutases, and ATP-sulfurylases. The expression of miR395, which targets sulfate metabolizing enzymes, is induced by sulfate- starvation, demonstrating that miRNA expression can be responsive to growth conditions.
(cont.) We investigated the biological role of miR394-mediated regulation of Atlg27340, an F-box gene of previously unknown function. Transgenic plants expressing a miR394-resistant version of Atlg27340 displayed a range of developmental abnormalities, including radialized and fused cotyledons, absent shoot apical meristems, curled and radialized leaves, and abortive flowers. The severity of these abnormalities correlated with the overaccumulation of Atlg27340 mRNA. These findings confirm the biological relevance of the interaction between miR394 and Atlg27340, and represent the first insights into the roles of miRNA-mediated regulation of F-box genes. Our results establish that both MIR394 and Atlg27340 are important regulators of meristem identity, and suggest that Atlg27340 targets an activator of class III HD-ZIP function for ubiquitination and proteolysis.
by Matthew W. Jones-Rhoades.
Ph.D.

Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management, 2004.
"June 2004 -- revised October 2004."
Includes bibliographical references (leaves 47-48).
Experiential Learning programs have increasingly been included in corporate training programs. Today there is a wide range of experiential learning programs using a variety of methodologies. However, there is a surprising dearth of research on the effectiveness of such programs for learning in business. This thesis reviews and analyzes one form of experiential learning--a program that utilizes outdoor activities for leadership and teamwork training--to understand the value proposition of such education for corporate clients. From this, a framework for implementing a successful experiential learning program was suggested and then analyzed by the design and delivery of a new, original experiential training program utilizing improvisational theater techniques. Finally, a method to evaluate experiential learning programs both before and after purchase is suggested.
by Lakshmi Balachandra.
M.B.A.

Current efficiency measurements of variable hydraulic axial piston pumps are performed with the displacement system locked at maximum volume, thus without the controller. Therefore, the controller’s effect on the efficiency is not quantified at state of the art measurements. Former research on control systems mainly focused on the dynamic behaviour. This paper aims to quantify the losses in the displacement and control system and to research the dependencies of those. Therefore, a test rig is built up at IFAS to measure the control power of displacement controlled pumps. Furthermore, a simulation tool is developed to increase the understanding of the loss mechanisms of the investigated control systems. In conclusion, the paper shows the potential of efficiency improvements for displacement controlled pumps.

Brief experimental analysis (BEA) has shown to be an effective method of rapidly testing the relative effects of two or more interventions in order to determine interventions that best supports a student’s learning. Little research has been found in regards to the consistency of methods across studies. A meta-analysis in 2008 by Burns and Wagner looked at BEAs that assessed oral reading fluency and provided recommendations for future practice. This study investigates the methods, procedures, and outcomes in BEA studies from 1994 to 2016. The findings of this study are compared to Burns and Wagner’s (2008) recommendations from their meta-analysis, as well as used to discuss the shifts and consistencies found in BEA methodology over the past 23 years. There is not sufficient evidence that Burns and Wagner’s (2008) recommendations have greatly impacted the process of BEA, but there have been changes in predominant methodological components of BEA such as the explicit use of conceptual models, methods of assessing interventions, and the emergence of a problem solving model to inform intervention selection. A general increase in the publication rate and a shift to publication in school psychology journals over behavioral journals was also noted. BEA outcomes continue to support its utility for informing instruction.

Includes abstract.
Includes bibliographical references.
This study was designed to assess the potential role of PCT, and to better understand the public's response to mitigation policy, within the context of South Africa. An experiment was conducted that simulated a personal emissions trading scheme.

Mestrado em Engenharia Mecânica
A presente investigação contempla a simulação numérica e validação experimental de processos de maquinagem. O estudo consiste na simulação numérica da maquinagem de materiais de alto desempenho como a liga de alumínio 7075 e o aço inox AISI 316 com validação experimental. Diversas simulações e validações foram conduzidas de modo a cobrir uma gama de parâmetros de maquinagem. Forças de corte e de avanço, potência de maquinagem, máxima temperatura de corte e deformação plástica foram validadas com sucesso. Finalmente, foram modeladas outras grandezas nomeadamente tensões residuais no aço inoxidável. ABSTRACT: The present investigation contemplates numerical simulation and experimental validation of machining processes. The study consists in simulating the machining of high performance materials like aluminium alloy 7075 and stainless steel AISI 316 with experimental validation. Several simulations and validations were conducted in order to cover a wide range of machining parameters. Cutting and feed forces, cutting power, maximum cutting temperature and plastic strain were validated with success. Finally, residual stresses in stainless steel were also modelled.

This thesis is concerned with flows relating to the continuous coating of multiple layers on moving webs using the slide bead process. The lowermost layer is generally known as a carrier layer when the viscosity and flow rate are both small compared with the corresponding properties of the other layers. This study is predominantly experimental in nature and broad in scope as addressing issues relating to an industrial slide coating process used for the manufacture of photographic products and inkjet media. Novel specialist pieces of equipment have been designed and built for visualizing such flows as part of this work. The studies have been carried out using a pilot coating machine and ancillary flow control facilities currently owned by HARMAN technology Limited. The new techniques enable fresh insight into the interaction between the carrier layer and the surface properties of the substrate, including roughness, surface free energy, electric charge and porosity - an area of investigation that has hitherto been largely ignored. The behaviour of the bead when coating embossed webs showing a "stippled" finish is of particular interest when compared with apparently equally rough substrates of equivalent surface energy. Increasing slide angle is shown to be advantageous to expanding the coating window for difficult substrates. The results show that the widely perceived criteria for a carrier layer needs to be redefined when coating rough surfaces of low surface energy using this process. Charge assisted coating is shown likely to be superior to conventional slide bead coating for minimising waste due to streaks. The studies include the visualisation of flows at the slot exit and on the slide. The methods allow the profile of the interface as well as the free surface to be monitored and give new insight into two major unreported effects limiting the use of a thin low viscosity carrier layer. The scope also extends to the study of waves induced in the surface of wet multi-layer coatings when subjected to the impact of air from an impingement dryer - an area of considerable interest to the coating technologist yet largely ignored by the equipment supplier.

La preservazione e la conservazione delle murature storiche si basano anche su un’appropriata conoscenza delle loro tecniche costruttive e del loro comportamento meccanico. In passato la mancanza di un’appropriata conoscenza dell’influenza delle tecniche costruttive delle murature sul loro comportamento meccanico ha spesso causato interventi errati e poco efficaci e, in alcuni casi, l’incremento delle vulnerabilità strutturali. La scelta dei parametri che influenzano il comportamento meccanico delle murature non può essere demandato unicamente alla letteratura tecnica che spesso descrive solo le tipologie di muratura più diffuse e non tiene conto dell’influenza della tecnologia costruttiva locale sulle prestazioni meccaniche delle murature investigate. Partendo da queste considerazioni generali, alcune murature romaniche di una chiesa, costituite da frammenti di tegole e di mattoni di reimpiego, sono state studiate attraverso un approccio multidisciplinare. La prima fase della ricerca è stata l’analisi delle tecniche costruttive. Nella seconda fase sono state eseguite analisi di laboratorio per determinare le proprietà chimiche, fisiche e meccaniche dei materiali in opera (frammenti di tegole e di mattoni, malta). In una terza fase sono stati riprodotti dei provini di muratura impiegando gli stessi materiali e la stessa tecnica costruttiva delle murature investigate. Le prove di compressione sui provini di muratura hanno permesso di accertare l’influenza della tecnologia e della tecnica costruttiva sull’intero comportamento meccanico delle murature investigate ed, in generale, di incrementare la conoscenza attuale sulle murature storiche. Infine, il metodo NSCD (Non-Smooth Contact Dynamics method) è stato applicato per investigare il comportamento dinamico delle strutture in esame. Sono state eseguite delle analisi parametriche applicando un accelerogramma reale al basamento del modello tridimensionale della chiesa.
The preservation and the conservation of historical masonries are also based on an appropriate knowledge of their constructive techniques and their mechanical behaviour. In the past the lack of knowledge about the influence of the constructive techniques of the masonries on their mechanical behaviour had often caused wrong and out of context repairs and in some cases the increment of the structural vulnerabilities. The choice of the parameters that influence the mechanical behaviour cannot be delegate only to the technical literature, that often describe only the most common types of masonry and it does not take into account the influence of the local constructive technology on the mechanical performances of the investigated masonries. Starting from these general considerations, some Romanesque masonries, made by tile and brick fragments, of a church were studied by a multidisciplinary approach. The first step of the research was the analysis of the constructive techniques. In a second phase the analyses of the chemical, physical and mechanical properties of the original materials (tile and brick fragments, mortars) were carried out by laboratory tests. In a third phase, wall specimens were built with the same materials and constructive technique of the investigated masonries. The results of the compression tests on the reproduced wall specimens allowed to assess the influence of the technology and the constructive technique on the entire mechanical behaviour of the investigated masonries and, in general, to increment the current knowledge on the historical masonries. Finally, the Non-Smooth Contact Dynamics (NSCD) method was applied to investigate the dynamical behaviour of the considered structures. Parametric analyses were carried out considering a real earthquake accelerogram applied to the supporting base of the threedimensional church.

This research project consists in a theoretical and experimental study of oligopolistic markets. I believe that an experimental approach to this subject might help to understand the interplay of the many different factors that affect firms behavior in this context, and to analyze problems which theory does not provide a clearcut answer to. My project develops into two main parts: the first concern how firms can learn to collude tacitly, the second studies deterrence of explicit collusion.

Heat dissipation is one of the most important issues for the reliability of electronics equipment. Up today, air represents the most safe, cheap, and common working fluid for electronics thermal management applications. Due to its poor heat transfer characteristics, air always flow through enhanced surfaces, such as plain and louvered fins, pin fins, offset strip fins and wire screens, in order to increase the heat transfer area and to create turbulence. Recently, metal foams have been proposed as promising enhanced surfaces to improve the overall heat transfer performance of the cooling system. In several applications air might be not enough for high level of heat dissipation, thus two-phase systems can represent a viable solution. Boiling is the heat transfer mechanism with the highest heat transfer coefficients, thus it can be used to spread high heat fluxes to maintain the wall temperature at low values with compact heat sinks. Microstructured surfaces, such as metal foams and microfin tubes, can exploit positive benefits on the flow boiling mechanism, i.e. they can promote bubble nucleation, reduce onset of nucleate boiling, augment two-phase mixing, enhance critical heat flux. On the other hand, the environmental issues associated to the use of synthetic refrigerants call for a continuous improvement of the technical solutions. Recently, new low-GWP refrigerants, in particular R1234ze(E) and R1234yf, have been proposed as possible alternatives of the traditional R134a. This PhD thesis explores the use of microstructured surfaces for thermal management applications. Metal foams, plain finned and pin finned surfaces are experimentally and numerically investigated during air forced convection. In addition, single- and two-phase flow (vaporization) of refrigerants through a copper foam and in a microfin tube is experimentally studied. The first chapter is focused on the air forced convection through metal foams. Nine copper foams are experimentally tested, and the overall heat transfer coefficients and pressure drops are calculated from the experimental measurements. The effects of the geometrical parameters (foam core height, pore density, and porosity) on the thermal and hydraulic behaviour of such materials are discussed. The experimental data points, coupled with other measurements previously obtained on aluminum foams, have permitted the development of a new semi-empirical equation for the estimation of the foam finned surface efficiency and of the heat transfer coefficient. The air forced convection through plain finned and pin fin surfaces is discussed in the second chapter. Numerical simulations are performed on different geometrical configurations of fin thickness, pitch, and height for the plain finned surfaces, and different configurations of pin diameter, longitudinal and transverse pin pitch, and pin height for the pin fin surfaces. The effects of the geometrical characteristics on the thermal and hydraulic behaviour are reported. From the numerical results, four correlations have been developed for the estimation of the Colburn j-factor and friction factor for plain finned and pin fin surfaces. In the end, an optimization of a plain finned surface is reported. The third chapter proposes a numerical approach to study the air forced convection through metal foams. The real structure of four copper foams, whose experimental results are reported in the first chapter, is obtained by micro-computed tomography scanned images. Once reconstructed, the real foams are meshed and the air flow simulated with a commercial software. Numerical results of pressure drop and heat transfer coefficient are compared against the experimental values. The design and development of a new experimental facility to study the phenomenon of the flow boiling inside microstructured surfaces is reported in the fourth chapter. The numerical design of the test section, which hosts a 200 mm long metal foam, is presented. Every component of the set up is discussed in details. The results of the calibration tests are reported. The flow boiling of refrigerants inside a metal foam is shown in the fifth chapter. The tested copper foam is 200 mm long, 10 mm wide, and 5 mm high. Three different refrigerants are studied: R134a, R1234ze(E), and R1234yf. R1234ze(E) and R1234yf (GWP=6 and 4, respectively) are possible substitutes of R134a (GWP=1400). Tests are run at a saturation temperature of 30 °C, which can be considered suitable for the case of electronic cooling applications, at different working conditions, in order to highlight the effects of the vapour quality, mass velocity, and heat flux on the thermal and hydraulic performance. Finally, the sixth chapter reports some results about the flow boiling of refrigerants inside a 3.4 ID microfin tube. Three different refrigerants are studied: R134a, R1234ze(E), and R1234yf. As for the case of flow boiling inside a metal foam, tests are run at a saturation temperature of 30 °C under different working conditions, i.e. different vapour quality, mass velocity, and heat flux. The experimental results of heat transfer coefficient, vapour quality at the onset of the dryout, and pressure drop are compared against values predicted by correlations from the open literature
Lo smaltimento di calore è uno degli aspetti più importanti per l’affidibilità di componenti elettronici. Ad oggi, l’aria è il più sicuro, economico e utilizzato fluido operativo in applicazioni di raffreddamento di componentistica elettronica. A causa delle sue scarse qualità di scambio termico, l’aria fluisce attraverso superficie estese, come alette piane, cilindriche e louvered, “offset strip fins” e “wire screens”, per aumentare la superficie di scambio termico e per creare turbolenza. Recentemente, le schiume metalliche sono state proposte come promettenti superfici estese per incrementare le prestazioni termiche del sistema di raffreddamento. Tuttavia, l’aria potrebbe non essere sufficiente nel caso in cui i flussi termici da asportare siano particolarmente alti e pertanto i sistemi bifase possono essere una soluzione attuabile. La vaporizzazione è il meccanismo di scambio termico con i maggiori coefficienti di scambio termico, pertanto può essere usato per dissipare elevati flussi termico e mantenere la temperatura di parete del dissipatore entro limiti che siano compatibili con quelli delle apparecchiature elettroniche. Superfici microstrutturate, come schiume metalliche e tubi microalettati, possono avere benefici nella vaporizzazione, cioè possono incrementare i siti di nucleazione delle bolle, anticipare l’ebollizione nucleata, aumentare il miscelamento tra la fase liquida e vapore, aumentare il flusso termico critico. Importanti sono anche gli aspetti ambientali associati a refrigeranti sintetici, situazione che richiede un miglioramento delle soluzioni tecniche attualmente impiegate. Recentemente, nuovi refrigeranti a basso impatto ambientale, in particolare l’R1234ze(E) e l’R1234yf, sono stati proposti come alternative al tradizionale R134a. Questa tesi di dottorato esplora l’uso di superfici microstrutturate in sistemi di raffreddamento. Sono state studiate sperimentalmente e numericamente schiume metalliche, alette piane e cilindriche durante la convezione forzata di aria. Inoltre,è stato sperimentalmente studiato il deflusso monofase e bifase (vaporizzazione) di refrigeranti in una schiuma metallica in rame e all’interno di un tubo microalettato. Il primo capitolo si focalizza sulla convezione forzata di aria attraverso schiume metalliche. Nove schiume in rame sono sperimentalmente studiate e dalle misure sperimentali vengono calcolati i coefficienti globali di scambio termico e le perdite di carico. Vengono discussi gli effetti dei parametri geometrici (altezza della schiuma, densità di pori e porosità) sul comportamento termico e idraulico di tali materiali. I punti sperimentali raccolti, insieme ad altre misure sperimentali precedentemente ottenute su schiume in alluminio, hanno permesso lo sviluppo di una correlazione per la stima dell’efficienza e del coefficiente di scambio termico. La convezione forzata di aria attraverso alette piane e cilindriche è discussa nel secondo capitolo. Sono state condotte simulazioni numeriche su differenti configurazioni geometriche di spessore, passo e altezze delle alette nel caso di alette piane, e di diametro, passo longitudinale e trasversale e altezza nel caso di alette cilindriche. Vengono riportati gli effetti delle caratteristiche geometriche sul comportamento termico e idraulico. Dai risultati numerici, sono state sviluppate quattro correlazioni per la stima del fattore j di Colburn e del fattore f di attrito per alette piane e cilindriche. Infine, è riportato un esempio di ottimizzazione di una superficie con alette piane. Il terzo capitolo propone un approccio numerico alla modellizazione della convezione forzata di aria in schiume metalliche. La reale struttura di quattro schiume in rame, i cui risultati sperimentali sono riportati nel primo capitolo, è ottenuta mediante immagini ottenute con la tecnica della microtomografia. Il deflusso di aria è quindi simulato con un software commerciale. I risultati numerici sulle perdite di carico e sui coefficienti di scambio termico sono quindi confrontati con i risultati sperimentali. Il dimensionamento e lo sviluppo di un nuovo impianto sperimentale per lo studio del fenomeno della vaporizzazione in superfici microstrutturate è riportato nel quarto capitolo. Viene presentato lo sviluppo mediante un codice numerico della sezione di prove, che alloggerà una schiuma metallica lunga 200 mm. Ogni componente dell’impianto è discusso in dettaglio. Infine vengono riportati i risultati della calibrazione dell’impianto. I risultati relativi alla vaporizzazione di refrigeranti all’interno di una schiumametallica sono presentati nel quinto capitolo. La schiuma metallica in rame è lunga 200 mm, larga 10 mm e alta 5 mm. Tre diversi refrigeranti sono studiati: R134a, R1234ze(E), and R1234yf. L’R1234ze(E) e l’R1234yf (GWP=6 e 4, rispettivamente) sono possibili sostituti dell’R134a (GWP=1400). Le prove sperimentali sono state condotte ad una temperatura di saturazione di 30 °C, che è un valore idoneo al caso di raffreddamento di componenti elettronici, in diverse condizioni operative, al fine di evidenziare gli effetti del titolo di vapore, della portata specifica e del flusso termico sulle performance termiche ed idrauliche. Nel sesto ed ultimo capitolo vengono riportati alcuni risultati sulla vaporizzazione di refrigeranti all’interno di tubo microalettato avente un diametro interno di 3.4 mm. Tre diversi refrigeranti sono studiati: R134a, R1234ze(E), and R1234yf. Come nel caso precedente, le prove sono state condotte ad una temperatura di saturazione di 30 °C in diverse condizioni operative, cioè a diverso titolo di vapore, portata specifica e flusso termico. I risultati sperimentali del coefficiente di scambio termico, del titolo di vapore all’inizio della crisi termica e delle perdite di carico sono confrontati con i valori stimati da alcune correlazioni empiriche proposte in letteratura

To provide the average golfer with more consistent results, manufacturers have continued to improve the available equipment. This has led to larger club-heads, with larger ?sweet spots?, different shaft thickness for different swing styles, and the use of advanced materials, such as graphite and titanium, for the construction. The development of improved equipment, which utilizes advanced materials, has spurred the need for advanced scientific analysis using a variety of techniques. Among the most prevalent of these methods are finite element analysis and experimental modal analysis, and use of these techniques in examining a golf club is the focus of this research. The primary goals of this work are the development and correlation of an appropriate finite element model, the characterization of the hands-free boundary condition and the examination of the club golf dynamic response. To accomplish these objectives, the physical parameters of the golf club are determined to develop the finite element model. The analysis of natural frequencies and mode shapes correlate well with the results extracted from experimental modal analysis for the free-free and clamped-free boundary conditions. With the correlation established, a third boundary condition, hands-free, is tested experimentally to ascertain the effects of the golfer?s grip on the boundary conditions. With the FEA model confirmed, a nonlinear dynamic response of the club during the down-swing is investigated using the nonlinear solver in Algor, and the club-head position relative to the shaft is predicted.
Master of Science

Whole-interval Differential Reinforcement of Other Behaviours (DRO), which reinforces set periods of behaviour absence, has been a widely used treatment in the reduction of inappropriate behaviours. Momentary DRO, a variant of this schedule which reinforces behaviour absence only at specific moments, may offer higher levels of reinforcement for clients and greater ease of administration. The primary aim of this thesis was to investigate the relative effectiveness of momentary DRO and whole-interval DRO in reducing inappropriate behaviour. The thesis also examined the claims that momentary DRO delivers greater reinforcement than whole-interval DRO and that momentary DRO is easier to programme. Experiments 1 to 6 showed momentary DRO to be at least as effective as whole-interval DRO in reducing inappropriate behaviour. There was also evidence to suggest momentary DRO produced a more rapid behaviour reduction and that it was more effective in reducing non-targeted inappropriate behaviours. Experiments I, 6 and 7 showed that momentary DRO consistently delivered higher levels of reinforcement than whole-interval DRO. Contrary to predictions, whole-interval DRO was reported to be as easy to administer as momentary DRO (Experiments 9 and 10). However, as subjects did not programme both schedules this result must be considered provisional. Experiments 9 and 10 showed that reinforcement was delivered more accurately in whole-interval DRO, although there was evidence to suggest that administration of this schedule was more effected by concurrent tasks than momentary DRO. It can therefore be concluded that the effectiveness of momentary DRO has been underestimated. It is clear, in view of its effectiveness and of the greater density of reinforcement it provides, that momentary DRO presents a viable, and in some cases superior, alternative to whole-interval DRO in the reduction of inappropriate behaviour.

Effective connectivity in functional neuroimaging studies is defined as the time dependent causal influence that a certain brain region of interest (ROI) exerts on another. Structural equation modeling (SEM) is regularly employed to analyze effective connectivity. In recent years, various SEM methods have been proposed to model effective connectivity. However, there has been little attempt to develop SEM methods for analyzing common patterns of effective connectivity across subjects despite the prevalence of multiple-subject research in effective connectivity. This dissertation proposes a method that fills this gap. This method is called dynamic generalized (multiple-set) structured canonical correlation analysis (dynamic GCANO). It combines generalized (multiple-set) canonical correlation analysis (GCANO) with a multivariate autoregressive time series model in a unified framework. This dissertation begins with a brief review of existing SEM techniques, and points out their limitations in analyzing multiple-subject effective connectivity data, which serves as a motivation to develop dynamic GCANO. The technical underpinnings of the proposed method are then stated, including specifications of a modeling framework and an optimization criterion for parameter estimation, which is minimized by an alternating least squares algorithm. The effectiveness of dynamic GCANO is demonstrated by analyzing both synthetic and real data sets. The former reveals reasonably good parameter recoveries by the proposed method, while the latter shows the usefulness of the method in empirical research. Several features of dynamic GCANO are highlighted through these examples. The dissertation concludes with possible extensions of the proposed method.
Suivant les méthodes d'imagerie fonctionnelle cérébrale, une connectivité efficace est définie comme influence dépendant de causalité temporelle qu'une certaine région d'intérêt du cerveau (ROI) exerce sur une autre. La modélisation par équation structurelle (SEM) est régulièrement utilisée pour analyser la connectivité efficace. Ces dernières années, diverses méthodes de SEM ont été proposées pour la modélisation de la connectivité efficace. Cependant, il y a eu peu de tentative pour développer des méthodes de SEM pour analyser les modèles communs de connectivité efficace sur-sujets, malgré la prédominance de recherche sur des sujets multiples pour analyser la connectivité efficace. Cette thèse propose une méthode qui comble cette lacune. Cette méthode est appelée dynamique généralisée (multiples ensemble) structuré l'analyse de corrélation canonique (dynamique GCANO). Elle combine généralisée (multiples ensemble) structuré l'analyse de corrélation canonique (GCANO) avec multivariée des séries chronologiques autorégressif dans un cadre unifié. Cette thèse commence par un bref sommaire sur les techniques existantes de SEM et souligne leurs limites pour analyser les données de plusieurs sous réserve pour la connectivité efficace, ce qui a mené à développer la dynamique GCANO. Les techniques de base de la méthode proposée sont ensuite énumérées, y compris les spécifications du cadre de modélisation et un critère d'optimisation pour l'estimation de paramètres, qui est réduit par alternant algorithme des moindres carrés. L'efficacité du dynamique GCANO est démontrée par l'analyse des ensembles de données synthétiques et réels. Les données synthétiques montrent une récupération raisonnable de paramètre par la méthode proposée, alors que les données réelles montrent l'utilité de la méthode dans les recherches empiriques. Plusieurs fonctionnalités du dynamique sont mises en évidence par le biais de ces exemples. En conclusion, la thèse propose des extensions possibles de la méthode proposée.

Memories once acquired, are retained in a stable state that is relatively impervious to change. However, following reactivation these memories are destabilized and require a reconsolidation process to once again be stabilized. If the reconsolidation process is disrupted, amnesia will ensue. This has opened the possibility that reconsolidation could be used a therapeutic tool for attenuating detrimental memories such as those that govern post-traumatic stress disorder and drug addiction. Contextual cues previously associated with rewarding drugs induce powerful cravings which are believed to be a major cause of relapse. Disrupting memory reconsolidation for these associations may provide a means to attenuate cue-induced craving and relapse. This thesis shows that post-reactivation administration of the amnestic agents propranolol and midazolam will disrupt a morphine place preference in a manner consistent with reconsolidation blockade. A further study shows that over-learning acts as a boundary condition that inhibits reconsolidation. However the impact of memory strength can be overcome by allowing the memory to age and decay prior to reactivation. Another study demonstrates that post-reactivation propranolol treatment disrupts reconsolidation when administered immediately after a first, but not a second, non-reinforced reactivation session. This suggests that a certain degree of novelty is required at the time of reactivation for reconsolidation to be triggered. Finally the impact of drug dependence on the reconsolidation phenomenon is explored and shown to produce resistance to post-reactivation amnesia. In fact, it reverses the effect of propranolol and results in an enhancement of the preference for the drug-paired cues. These findings support the concept of reconsolidation as a therapeutic approach for treating cue-induced relapse in former drug addicts, but highlight the critical impact that prior dependence may have on the phenomenon.
Une fois acquises, nos mémoires sont préservées dans un état stable et à l'écart de tout changement. Cependant, suivant leur réactivation, ces mémoires sont déstabilisées et exigent un processus de reconsolidation afin d'être stabilisé de nouveau. Or lorsque ce processus de reconsolidation est perturbé, l'amnésie survient. De là a découlé l'idée d'exploiter le processus de reconsolidation en tant qu'outil thérapeutique afin d'atténuer, voire d'éliminer, les mémoires nuisibles comme celles qui régissent le syndrome de stress post-traumatique et la toxicomanie. Les associations contextuelles liées à l'usage de certaines drogues d'abus induisent des désirs de consommation, lesquels constituent une cause majeure de rechute. La perturbation de la reconsolidation de la mémoire pour ces associations peut fournir un moyen d'atténuer ces désirs et ainsi réduire les taux de rechute. Cette thèse démontre que l'administration post-reconsolidatoire de certains agents amnésiques - le propranolol et le midazolam - perturbe une préférence conditionnée d'endroit à la morphine d'une manière compatible avec une interférence du processus de reconsolidation. Elle prouve également que le sur-apprentissage d'une association agit de manière à empêcher l'enclenchement de la reconsolidation. Cependant la robustesse d'une mémoire peut être surmonté en permettant à cette mémoire de vieillir et se délabrer avant la réactivation. Une autre étude démontre que le traitement avec propranolol suivant la réactivation perturbe la reconsolidation une fois administré juste après une première séquence de réactivation, mais non après une seconde. Cela suggère qu'un certain degré de nouveauté est nécessaire au moment de la réactivation pour que la reconsolidation soit déclenchée. Cette thèse explore, en dernier lieu, l'impact de la dépendance à la drogue sur le phénomène de reconsolidation. Les résultats démontrent ici qu'une dépe

Leakage is a widespread problem associated with the construction of diaphragm walls whenever they are erected in water-bearing ground. The aim of the present research is to develop a new type of slurry wall: the bi-layer diaphragm wall (BL), which main objective is to tackle the aforementioned problem. The method to construct it is based on an existing solution: casting a second waterproof concrete layer against the diaphragm walls. In the BL technique, the second layer is made of steel fibre reinforced concrete (SFRC) sprayed over the conventional diaphragm wall (called Mono-Layer diaphragm wall (ML) in this thesis), including a waterproof admixture. The central idea is to maximize the functional attributes of the second layer, allowing it to play a structural role in addition to the waterproofing function.The proposed methodology is based on a combination of experimental works and numerical tools. A design method for the BL walls, which is based on an uncoupled structural-section model, is proposed. The method is later used to carry out different comparisons with ML walls and an exhaustive parametric analysis of the construction processes involved in the walls construction. The experimental campaign comprised test at two levels. At element level, the structural response of walls built in a real building located in Barcelona was studied and, at section level, the bond strength between concretes of cores extracted from the abovementioned walls was measured.The model at structural level, which is based on a finite element model, was contrasted with the results obtained in the experimental walls. The sectional analysis is taken from the specialized literature. With the complete structural-section model, the BL walls are analysed. The study shows that the main flexural resistance is provided by the first layer (the conventional diaphragm wall), providing the SFRC layer a secondary flexural resistance.For the geometrical ranges of the elements considered in the thesis (35 cm to 60 cm width first layer, and 10 cm width second layer) the increase in the cross-section ultimate bending resistance when it is strengthened by the SFRC layer is between 8% and 15%. This increase allows a reduction in the steel reinforcement of the first layer (up to 7.0% of the total flexural reinforcement) and, to some extent, it also collaborates with a displacement reduction (reducing up to 7.3% of the maximum displacements). It was also found that the spraying sequence is a crucial parameter to be able to take advantage of the SFRC collaboration, and specific indications are described.Good concrete to concrete bond strength was obtained for the extracted cores. The average shear strength value measured for each age (2, 6 and 35 days) was always above 1.0 MPa for the different cases. Beyond the local test performed, a monolithic behaviour was observed at element level in the experimental walls.A similar final material consumption was observed between the BL walls and the combined consideration of a ML wall and an external waterproof system. The consideration of the technology cost entails a higher construction cost for the BL technique. However, it is still an interesting option under particular circumstances, like space limitations or if continuous maintenance costs want to be avoided in the future.In general terms it can be said that the research herein presented lay the foundation for the development of the bi-layer diaphragm wall technique, which is a promising solution for the leakage problem of diaphragm walls. Nonetheless, more studies are needed to be able to fully use these types of walls as a standard technique, e.g. a detailed cost study and sustainability analysis, debonding risk, waterproofing capability and above all more full scale experimental cases.
Un problema habitual en la construcción de pantallas continuas en terrenos con presencia de agua es la existencia de filtraciones. El objetivo de esta tesis busca resolver este problema mediante el desarrollo de un nuevo tipo de pantalla: la pantalla bi-capa (BL, por sus siglas en inglés). El método para construir estos muros se basa en una solución existente: realizar una segunda capa de hormigón impermeable sobre los muros pantalla. En las pantallas BL, la segunda capa se realiza con hormigón con fibras de acero (SFRC) proyectado sobre las pantallas convencionales (llamadas ML en esta tesis) e incluyendo a su vez una adición impermeabilizante. La idea central es maximizar las funciones de la segunda capa, asignándole un rol estructural, además de la función impermeabilizante. La metodología propuesta se basa en la combinación de trabajos experimentales y herramientas numéricas. Se propone un método de diseño para las pantallas BL basado en modelos estructura-sección desacoplados. Posteriormente se utiliza este método para realizar diferentes comparaciones con pantallas ML y un análisis paramétrico exhaustivo de distintos procesos constructivos involucrados en la construcción de las pantallas BL. La campaña experimental realizada comprende dos niveles: a nivel elemento, se estudió la respuesta estructural de pantallas construidas en un edificio real ubicado en Barcelona; a nivel seccional, se midió el nivel de adherencia entre ambas capas de hormigón mediante testigos extraídos de las pantallas antes mencionadas. El modelo a nivel estructural, basado en elementos finitos, se contrastó con los resultados experimentales obtenidos. El modelo seccional se tomó de la bibliografía estudiada. Con el modelo estructura-sección completo se analizaron las pantallas BL. El estudio muestra que la principal resistencia flexional es aportada por la primera capa (el muro pantalla convencional), siendo secundario el aporte de la capa de SFRC. Para el rango de elementos considerados en esta tesis (35 cm a 60 cm de espesor de primera capa y 10 cm de segunda), el incremento de la resistencia última a flexión cuando se considera el aporte de la capa de SFRC, está entre 8% y 15%. Este incremento permite una reducción en el acero de refuerzo de la primera capa de hasta un 7.0% del total del acero de flexión y, hasta cierto punto, también colabora con una reducción en los desplazamientos (alcanzando reducciones de hasta un 7.3% del desplazamiento máximo). Se observó también que la secuencia de proyección es un factor clave a la hora de aprovechar la colaboración extra aportada por la capa de SFRC. Indicaciones específicas se describen a este respecto. Se obtuvo una buena resistencia de adherencia entre hormigones para los testigos extraídos. La resistencia media medida a cada edad (2, 6, y 35 días) estuvo siempre, para los distintos casos, por encima de 1.0 MPa. Más allá de los ensayos puntuales, se observó un comportamiento monolítico a nivel elemento para las pantallas BL experimentales. Se obtuvo un consumo final de materiales similar entre pantallas BL y la consideración conjunta de una pantalla ML más un sistema impermeabilizante externo. Considerar los costos tecnológicos conlleva un costo constructivo mayor para las pantallas BL. Sin embargo, ésta es aún una opción interesante bajo consideraciones particulares, como limitaciones del espacio subterráneo interior o si se desean evitar costos continuos de mantenimiento. En términos generales, se puede decir que la investigación aquí presentada sienta las bases para el desarrollo de la técnica de muros pantalla bi-capa, la cual es una solución prometedora para el problema de las filtraciones en pantallas. No obstante, son necesarios más estudios para poder usar plenamente este tipo de pantallas de forma habitual, e.g. estudios de sostenibilidad detallados, evaluación del riesgo de desprendimiento de la segunda capa, capacidad impermeable y, sobre todo, más ensayos experimentales a escala real

Aquesta tesi analitza diversos aspectes de les motivacions individuals i de les seves implicacions en processos econòmics. Específicament, analitzo en detall criteris normatius que poden aplicar els individus com són els de justícia i reciprocitat. En la Introducció defineixo l'ús que en faig de conceptes com la reciprocitat, la justícia, la "dependència del menú" i els "punts de referència" donat que s'empren en el desenvolupament dels diferents capítols. També es descriu la metodologia emprada, que consisteix en alguns models teòrics sobre el comportament dels individus en situacions estratègiques, incorporant elements de la Teoria dels Jocs i l'ús de la metodologia experimental. En el segon capítol, " El concepte de justícia de Rabin i la provisió privada de béns públics", analitzo en detall les implicacions de la teoria de Rabin (1993) sobre el comportament estratègic d'individus. Aquest model introdueix en la funció d'utilitat , a més dels pagaments econòmics que un individu obté, aspectes psicològics com el sentit de justícia en les relacions econòmiques amb altres individus. En aquest capítol examino les implicacions d'una extensió de la teoria a un camp a on existeix una acumulació de resultats experimentals en contradicció amb el comportament predit pels models estàndard de la teoria dels jocs. Mostro que la teoria d'en Rabin és consistent amb el que s'anomena "splitting" però inconsistent amb el que es coneix com a "efecte MPCR". El tercer capítol, "Punts de referència i reciprocitat negativa en jocs seqüencials simples", analitza la influència que poden tenir certs vectors de pagaments no disponibles en un moment de decisió, anomenats "punts de referència", sobre la preferència per un altre conjunt de vectors de pagaments. Això es connecta amb l'atribució de certes intencions a altres subjectes quan trien determinats cursos d'acció en el joc. Mitjançant la utilització d'experiments s'obtenen resultats que confirmen la importància dels punts de referència en les consideracions de reciprocitat que empren els individus. El quart capítol, " Aspectes distribucionals i els punts de referència", analitza alguns aspectes que poden combinar-se amb els punts de referència en la atribució d'intencions. Aquests aspectes són: el pagament que podia rebre un agent en el punt de referència, el seu pagament relatiu a l'altre agent i, finalment, el pagament conjunt que podien obtenir els dos agents en el punt de referència. Els resultats experimentals obtinguts mostren que cap d'aquests efectes pot explicar per ell mateix els resultats. Finalment, el cinquè capítol, " Els joc del dilema dels presoners en forma seqüencial: Reciprocitat i efectes de dimensió del grup" estudia les reaccions dels individus a certes decisions d'altres individus del procés i els canvis d'aquestes reaccions amb la dimensió del grup. Els resultats experimentals obtinguts , mostren que el comportament observat és consistent amb consideracions de reciprocitat i d'aversió a la desigualtat.
This thesis analyzes several aspects of the motivations that drive individuals and their implications in economic processes. In particular, I analyze in detail normative criteria that individuals apply such as those of fairness and reciprocity. In the Introduction I define the use I make of the concepts of reciprocity, fairness, menu dependence and reference points that will be used in the course of the different chapters. The methodology developed in this thesis employs some theoretical models on the behavior of individuals in strategic interactions, using elements of Game Theory and Experimental Economics. In the second chapter, "On Rabin's Concept of Fairness and the Private Provision of Public Goods", I analyze in detail the implications of Rabin's (1993) theory of individual behavior and its implications. This model introduces, apart from the economic payoffs that the individual obtains in a strategic interaction, psychological phenomena, mainly a sense of fairness in the relation with other agents. In this chapter I analyze the implications of an extended version of this theory to a field where there exists a vast amount of experimental evidences contradicting the behavior predicted by standard game theoretical models. I show that Rabin's theory is consistent with one piece of evidence repeatedly found in experiments, the so call "splitting". I also show that the model is inconsistent with another piece of evidence in the field, the "MPCR effect". The third chapter, "Reference Points and Negative Reciprocity in Simple Sequential Games", analyzes the influence that certain payoff vectors, the "reference points", not attainable at that time, may have on the preference by other payoff vectors. This is connected with the attribution of certain intentions to the other players when selecting some courses of action. By using experiments I obtain results that confirm the importance of these reference points in the reciprocity considerations that individuals apply. Chapter four , "Distributional Concerns and Reference Points", analyzes some aspects that may interact with the reference points in the attributions of intentions. These aspects are the payoff to the agent from a given course of action, his/her relative payoff and the joint payoff. The experimental results show that none of these elements is able to explain by itself the results. Finally, the fifth chapter, "The Sequential Prisoner's Dilemma Game: Reciprocity and Group Size Effects" analyzes how aspects of the individual motivations interact with social aspects. In particular it studies how the reactions of individuals change with the dimension of the group in certain processes. The experimental results obtained show that in the prisoner's dilemma game (two-person and three-person games) the behavior of subjects may be consistent with reciprocity considerations and with inequality aversion considerations.

In this study, experimental modal analysis was studied. Experimental modal analysis includes modal testing, modal parameter estimation and calibration. For this purpose a 4 span skewed steel frame was constructed in Structural Mechanics Laboratory of Civil Engineering Department of METU. The model was transported to Vibration and Acoustic Laboratory of Mechanical Engineering Department of METU. The tests were conducted by cooperation with Vibration and Acoustics Laboratory. Due to lack of experimental modal analysis software in Structural Mechanics Laboratory, modal parameter estimation and finite element updating softwares were written in Matlab platform. The written softwares were executed on the data obtained from modal testing. 15 reasonable modes are extracted from the FRFs that are obtained from modal testing. 59.23 percent consistency is found for the nominal modal comparison. At the end of calibration process 76.14 percent consistency is achieved between the experimental results and analytical results.

The aerodynamics of two-dimensional and three-dimensional flapping motion in hover is analyzed in incompressible, laminar flow at low Reynolds number regime. The aim of this study is to understand the physics and the underlying mechanisms of the flapping motion using both numerical tools (Direct Numerical Simulation) and experimental tools (Particle Image Velocimetry PIV technique). Numerical analyses cover both two-dimensional and three-dimensional configurations for different parameters using two different flow solvers. The obtained results are then analyzed in terms of aerodynamic force coefficients and vortex dynamics. Both symmetric and cambered airfoil sections are investigated at different starting angle of attacks. Both numerical and experimental simulations are carried out at Reynolds number 1000. The experimental analysis is carried out using Particle Image Velocimetry (PIV) technique in parallel with the numerical tools. Experimental measurements are taken for both two-dimensional and three-dimensional wing configurations using stereoscopic PIV technique.