People make food choices based upon the motivation to consume foods that are reinforcing compared to alternatives that may be available.1 Delay discounting (DD) is a measure used to assess impulsivity, quantifying how people make decisions based on time to receive and amount of the choice presented. The food purchase task (FPT) assesses the demand for a food and how reinforcing this item is at various prices. Using a controlled feeding study design, 10 males (n=7 sedentary, n=10 endurance trained) consumed an iso-caloric, standard diet (55% carbohydrate, 30% fat, and 15% protein) for 10 days, followed by a high-fat diet (55% fat, 30% carbohydrate, 15% protein) for 5 days. DD, FPT, and Three Factor Eating Questionnaire (TFEQ) were assessed at three time points: baseline, after the standard diet/before high-fat diet, and after the high-fat diet. Discounting rates were significantly different at baseline between sedentary and endurance trained males, with the sedentary males having higher discounting rates (mean difference 1.43, p=.037). Discounting rates for the whole sample significantly decreased between baseline (time 1) and post-STD diet/before HFD (time 2), between time 2 and after the HFD (time 3), and between time 1 and time 3 (all indicated by p<0.05). No group differences were noted over time for demand elasticity, intensity, or TFEQ measures (all indicated by p<0.05). Results could be used to advance the understanding of factors that influence impulsive and unhealthy eating behaviors and inform the development of interventions that use reinforcers to positively influence eating behaviors. / MS / Choice is a fundamental part of life, and people make decisions based on a variety of different factors, such as the amount of effort required, perceived benefits and risks of the choice, what other options are available, and what resources the person has available to them (e.g., time, money). Many dietary and lifestyle choices are unhealthy, such as choosing to consume fast food in excess or to not engage in exercise. About 2/3 of Americans are overweight, and 1/3 are obese, and about 1 in 5 of American adults meet the guidelines recommended by the Centers for Disease Control of engaging in at least 150 minutes of moderate physical activity or 75 minutes of vigorous physical activity per week. Understanding the factors that influence unhealthy eating and lack of physical activity is crucial in order to develop effective programs that focus on changing these behaviors, as weight-loss or physical activity programs often require people to delay the immediate gratification of food in order to achieve optimal health outcomes. The present study investigates how a diet high in fat and exercise habits influence how people value rewards and make decisions. Delayed discounting is a tool used to determine much a person is influenced by immediate gratification of a reward versus waiting for a larger reward of greater worth that is available in the future. The food purchase task is used to quantify the reinforcing value of a food item by determining how much of a favorite snack food a person would purchase by depending on the price. Lastly, eating habits such as dietary restraint or loss of control are quantified by a questionnaire. Results could improve the understanding of factors that influence unhealthy decisions and support the creation of programs that aim to improve how people view and value future health outcomes.

This dissertation provides a comprehensive examination of the role of Transportation Networking Companies (TNC) across four dimensions. First, we examined the factors affecting Transportation Networking Companies (TNC) pricing and destination choice behavior using weekday TNC trip data from Chicago spanning January 2019 through December 2019. Towards achieving this goal, we developed a joint model framework where trip fare is modelled using linear regression model (LR) and destination choice is modelled using a multinomial logit model (MNL). Second, we build a systematic framework to analyze spatial TNC demand patterns (origins) across the urban region at the census tract (CT) level and compare them to overall transportation demand. We propose and compute a novel metric at the census tract level to identify the potential imbalance between overall transportation demand and TNC demand by developing a Generalized Ordered Logit. The model applicability is further illustrated through elasticity analysis. Third, based on earlier studies we identified that current TNC related macroscopic studies do not incorporate attributes at the microscopic resolution. We bridge the macroscopic and microscopic analysis using a bi-level modeling approaching that accommodates for the influence of microscopic attributes within the macroscopic modeling approach. In this proposed framework, the trip level destination choice model (microscopic model) takes the form of a multinomial logit model and the origin-destination flow model (macroscopic model) takes the form of a multinomial logit fractional split model. Finally, in our effort to incorporate TNCs into travel demand tools, we conducted a comprehensive literature review on studies examining the impact of TNCs on various components of travel demand models (TDM). We provide guidelines for potential travel demand model updates using three use case examples including vehicle ownership model, trip generation model, and trip level mode choice components.

No / The pharmaceutical powder and tableting process is simulated using a combined finite-discrete element method and contact dynamics for irregular-shaped particles. The particle-scale formulation and two-stage contact detection algorithm which has been developed for the proposed method enhances the overall calculation efficiency for particle interaction characteristics. The irregular particle shapes and random sizes are represented as a pseudo-particle assembly having a scaled up geometry but based on the variations of real powder particles. Our simulations show that particle size, shapes and material properties have a significant influence on the behaviour of compaction and deformation.

No / When a drop of liquid is placed on the surface of a soft material, the surface deformation and the rate of spreading of the triple contact point is dependent on the mechanical properties of the substrate. This study seeks to use drop spreading behavior to infer the mechanical properties of soft biological materials. As an illustration of the value of this technique we have compared the spreading behavior of a liquid droplet on two viscoelastic, soft materials, namely, an elastomer and a low concentration agar gel. The ratio of the mechanical properties of these soft materials obtained in this way is confirmed by atomic force microscopy (AFM) nanoindentation. By comparing the spreading behavior of a liquid on the retina with that of the same liquid on each of two viscoelastic materials, we can then estimate the elastic moduli of the retina: an estimate that is extremely difficult to carry out using AFM.

Feldspars are one of the archetypical families of framework silicates. They not only comprise around 60% volumetrically of the Earth's crust, but are among some of the most structurally complicated minerals. Investigation into the structural behavior of various intermediate plagioclases at pressure has been undertaken with the intent of categorizing the elastic behavior with pressure across the solid solution series and establishing a conceptual model to characterize feldspar compression. Complex behavior has been observed in the Equation of State for plagioclase feldspars in excess of 3 GPa, including an anomalous softening of ordered albite in excess of 8.4 GPa (Benusa et al 2005: Am Min 90:1115-1120). This softening was not observed in the EoS for the more intermediate plagioclase compositions containing between 20 and 40 mol% of end-member anorthite. The calculated elastic compliance tensor sums at room pressure show a general stiffening with increasing anorthite component, small elastic changes at the C-1 to I-1 transition, and a dominantly first-order response at the P-1 to I-1 transition near end-member anorthite. The crystal structure of An37 plagioclase was determined by single-crystal X-ray diffraction. The compression mechanisms in An37 are similar to those in albite at lower pressures. The softening in albite at higher pressures is therefore attributed to the structural shearing in albite that is absent in An37 plagioclase up to 9.5 GPa. / Master of Science

No / Closed-form expressions are derived for the torsional stiffness, radial stiffness and tilting stiffness of annular rubber flanged bushes of finite length in three principal modes of deformation, based upon the classical theory of elasticity. Illustrative numerical results are deduced with realistic physical data of typical flanged bushes.

No / Representations for the stress fields created around an infinite row of collinear, antiplane shear cracks moving within one-dimensional hexagonal quasicrystals, and the resulting stress intensity factors and the J-integral, are determined in closed-form and discussed, using an extended method of dislocation layers. The solutions for a finite quasicrystalline plate containing a single moving crack and a plate with a moving edge crack are also provided by this analysis. (C) 2014 Elsevier Ltd. All rights reserved.

Yes / : Understanding how cancer incidence evolves during economic growth is useful for forecasting the economic impact of cancerous diseases, and for governing the process of resources allocation in planning health services. We analyse the relationship between economic growth and cancer incidence in order to describe and measure the influence of an increasing real per capita income on the overall rate of cancer incidence. Method:We test the relationship between real per capita income and the overall rate of cancer incidence with a cross-sectional analysis, using data from the World Bank and the World Health Organization databases, for 165 countries in 2008. We measure the elasticity of cancer incidence with respect to per capita income, and we decompose the elasticities coefficients into two components: age-effect and lifestyle-effect. Results: An Engel’s model, in a double-log quadratic specification, explains about half of the variations in the age-standardised rates and nearly two thirds of the variations in the incidence crude rates. All the elasticities of the crude rates are positive, but less than one. The income elasticity of the age-standardised rates are negative in lower income countries, and positive (around 0.25 and 0.32) in upper middle and high income countries, respectively. Conclusions:These results are used to develop a basic framework in order to explain how demand-side economic structural changes may affect the long run evolution of cancer incidence. At theoretical level, a J-Curve is a possible general model to represents, other things being equal, how economic growth influence cancer incidence.

The thesis presents a novel computational method for analysing the static and dynamic behaviour of a multi-damaged beam using local and non-local elasticity theories. Most of the lumped damage beam models proposed to date are based on slender beam theory in classical (local) elasticity and are limited by inaccuracies caused by the implicit assumption of the Euler-Bernoulli beam model and by the spring model itself, which simplifies the real beam behaviour around the crack. In addition, size effects and material heterogeneity cannot be taken into account using the classical elasticity theory due to the absence of any microstructural parameter. The proposed work is based on the inhomogeneous Euler-Bernoulli beam theory in which a Dirac's delta function is added to the bending flexibility at the position of each crack: that is, the severer the damage, the larger is the resulting impulsive term. The crack is assumed to be always open, resulting in a linear system (i.e. nonlinear phenomena associated with breathing cracks are not considered). In order to provide an accurate representation of the structure's behaviour, a new multi-cracked beam element including shear effects and rotatory inertia is developed using the flexibility approach for the concentrated damage. The resulting stiffness matrix and load vector terms are evaluated by the unit-displacement method, employing the closed-form solutions for the multi-cracked beam problem. The same deformed shapes are used to derive the consistent mass matrix, also including the rotatory inertia terms. The two-node multi-damaged beam model has been validated through comparison of the results of static and dynamic analyses for two numerical examples against those provided by a commercial finite element code. The proposed model is shown to improve the computational efficiency as well as the accuracy, thanks to the inclusion of both shear deformations and rotatory inertia. The inaccuracy of the spring model, where for example for a rotational spring a finite jump appears on the rotations' profile, has been tackled by the enrichment of the elastic constitutive law with higher order stress and strain gradients. In particular, a new phenomenological approach based upon a convenient form of non-local elasticity beam theory has been presented. This hybrid non-local beam model is able to take into account the distortion on the stress/strain field around the crack as well as to include the microstructure of the material, without introducing any additional crack related parameters. The Laplace's transform method applied to the differential equation of the problem allowed deriving the static closed-form solution for the multi-cracked Euler-Bernoulli beams with hybrid non-local elasticity. The dynamic analysis has been performed using a new computational meshless method, where the equation of motions are discretised by a Galerkin-type approximation, with convenient shape functions able to ensure the same grade of approximation as the beam element for the classical elasticity. The importance of the inclusion of microstructural parameters is addressed and their effects are quantified also in comparison with those obtained using the classical elasticity theory.

Ce travail a été effectué dans le cadre du projet Rem3D® dans lequel participent plusieurs entreprises avec l'objectif de développer un logiciel d'injection en 3D par éléments finis. L'objectif est de développer une méthode numérique pour modéliser le comportement viscoélastique des polymères de l'état solide à l'état liquide à travers une approche multiphasique qui est largement utilisé pour traiter le problème de l'interaction fluide-structure (IFS). La philosophie est d'utiliser une formulation mixte de trois champs (u, v, p) (déplacement, vitesse, pression), où u et v représentent les principales variables de déformation et de vitesse de déformation. Nous sommes amenés au problème de Navier-Stokes compressibles avec l'extra-contrainte, qui est résolu en utilisant la méthode des éléments finis mixte. Le présent travail contribue aussi certains éléments de stabilisation pour la simulation numérique des problèmes multiphasiques par l'approche monolithique.Comparaison entre la littérature et l'expérience est accompli par la validation du cas élastique et cas modèle viscoélastique de Kelvin-Voigt dans le lagrangien approche ainsi qu'eulérien approche. L'extension de la méthodologie au modèle visco-hyper-élastique est débuté par la modélisation et la validation au point matériel, puis l'implémentation dans la bibliothèque des éléments finis CimLib®. Enfin, un schéma stabilisation de résolution du type EVSS est adopté pour le modèle viscoélastique de Kelvin-Voigt, le modèle visco-hyper-élastique de Néo-Hookean, et aussi le modèle visco-hyper-élastique qui propose une prometteuse porte ouverte dans la simulation et modélisation, non seulement pour la viscoélasticité, mais aussi pour les applications dynamique complexes. / This work concerns the simulation of viscoelastic behavior of polymer at different states. Viscoelastic modeling of polymer was performed from the solid state to the liquid state via a multiphase approach which is largely used to deal with the fluid structure interaction. To ensure the appreciation of the FSI, viscoelasticity is considered in two parts: an elastic one and viscous other where the main idea is to use a mixed formulation in three fields (u, v, p) (displacement, velocity, pressure), with u and v, represented the primary variables of a strain and a strain rate formulation. We are led to the Navier-Stokes compressible problem with extra-stress, which is solved by using the Mixed Finite Element. The present work contributes some stabilization elements to the numerical simulation of multiphase problem by the monolithic approach.Comparison between the literature and experiments was performed through the validation of an elastic case and the viscoelastic Kelvin-Voigt model in the context of Lagrangian framework as well as Eulerian framework. The extension of the methodology to a visco-hyper-elastic is given through the modeling and validation on material point on the finite elements library CimLib®. Finally, a stabilization scheme of the EVSS type is adopted for viscoelastic Kelvin-Voigt model, hyper-elastic Neo-Hookean model, and also visco-hyper-elastic model which proposed an open door in computational modeling, not only with viscoelasticity but also complex dynamic application.