Elastic deformation has wide applications in medical simulations, therefore when it comes to designing physical behavior of objects for realistic training applications, determining material parameters so that objects behave in a desired way becomes a crucial. In this work we consider the problem of elasticity parameter estimation for deformable bodies, which is important for accurate medical simulations. Our work has two major steps: the first step is the data acquisition and preparation, and the second step is the parameter estimation. The experimental setup for data acquisition consists of depth and force sensors. Surface deformations are acquired as a series of images along with the corresponding applied forces. The contact point of the force sensor on the surface is found visually and the corresponding applied forces are acquired directly from the force sensor. A complete mesh deformation which is obtained from a surface tracking method is employed along with force measurements in the elasticity parameter estimation method. Our approach to estimate the physical material properties is based on an inverse linear finite element method. We have experimented with two approaches to optimize the elasticity parameters: a linear iterative method and a force-displacement error minimization method. The two methods were tested on the simulation data, and the second method was tested on three deformable objects. The results are presented for the data captured by two different depth sensors. The result is a set of two parameters, the Young's modulus and the Poisson's ratio, which represents the stiffness of the object under test.

The development work of a race car revolves around numerous goals such as drag reduction, maximizing downforce and side force, and maintaining balance. Commonly, these goals are to be met at the same time thus increasing the level of difficulty to achieve them. The methods for data acquisitions available to a race team during the season is mostly limited to wind tunnel testing and computational fluid dynamics, both of which are being heavily regulated by sanctioning bodies. While these methods enable data collection on a regular basis with repeat-ability they are still only a simulation, and as such they come with some margin of error due to a number of factors. A significant factor for correlation error is the effect of tires on the flow field around the vehicle. This error is a product of a number of deficiencies in the simulations such as inability to capture loaded radius, contact patch deformation in Y direction, sidewall deformation and overall shifts in tire dimensions. These deficiencies are evident in most WT testing yet can be captured in CFD. It is unknown just how much they do affect the aerodynamics performance of the car. That aside, it is very difficult to correlate those findings as most correlation work is done at WT which has been said to be insufficient with regards to tire effect modeling. Some work had been published on the effect of tire deformation on race car aerodynamics, showing a large contribution to performance as the wake from the front tires moves downstream to interact with body components. Yet the work done so far focuses mostly on open wheel race cars where the tire and wheel assembly is completely exposed in all directions, suggesting a large effect on aerodynamics. This study bridges the gap between understanding the effects of tire deformation on race car aerodynamics on open wheel race cars and closed wheel race cars. The vehicle in question is a hybrid of the two, exhibiting flow features that are common to closed wheel race cars due to each tire being fully enclosed from front and top. At the same time the vehicle is presenting the downstream wake effect similar to the one in open wheel race cars as the rear of the wheelhouse is open. This is done by introducing a deformable tire model using FEA commercial code. A methodology for quick and accurate model generation is presented to properly represent true tire dimensions, contact patch size and shape, and deformed dimension, all while maintaining design flexibility as the model allows for different inflation pressures to be simulated. A file system is offered to produce CFD watertight STL files that can easily be imported to a CFD analysis, while the analysis itself presents the forces and flow structures effected by incorporating tire deformation to the model. An inflation pressure sweep is added to the study in order to evaluate the influence of tire stiffness on deformation and how this results in aerodynamic gain or loss. A comparison between wind tunnel correlation domain to a curved domain is done to describe the sensitivity each domain has with regards to tire deformation, as each of them provides a different approach to simulating a cornering condition. The Study suggests introducing tire deformation has a substantial effect on the flow field increasing both drag and downforce.In addition, flow patterns are revealed that can be capitalized by designing for specific cornering condition tire geometry. A deformed tire model offers more stable results under curved and yawed flow. Moreover, the curved domain presents a completely different side force value for both deformed and rigid tires with some downforce distribution sensitivity due to inflation pressure.

The objective of this study is to evaluate material response to plastic deformation between aluminum alloys AA2219-T87 and AA2195-T87. Of particular interest are the deformation conditions that result in subsequent grain refinement or recrystallization. Although both alloys have a face centered cubic (FCC) microstructure, variations are expected in their plastic deformation behavior. During plastic deformation, dislocation motion results in faulted regions whose width can vary according to chemical composition of the alloy. These faulted regions, or stacking faults, influence whether dislocation entanglements form or annihilation occurs during the deformation process. In addition, differences in mechanical properties can affect the amount of adiabatic heating that occurs during deformation. Ultimately these differences can affect the uniformity of deformation and the stability of the microstructure.

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This dissertation research consists of two parts: (i) investigation of quasiparticle alignments at high-spins and (ii) identification of triaxial strongly deformed structures in 168Hf. A γ-ray spectroscopy study was carried out, as well as lifetime measurements using the Doppler-shift Attenuation Method (DSAM). The two data sets used for this research were obtained from experiments at Argonne National Laboratory employing the reaction 96Zr(76Ge, 4n). The decay γ-rays were measured with the Gammasphere Compton-suppressed Ge spectrometer array. A self-supporting 96Zr foil ("thin target") was used in the first experiment, while in the second experiment the 96Zr target material was evaporated onto a thick Au backing ("backed target" or "thick target") to stop the recoiling nuclei for lifetime measurements. All previously known rotational bands have been extended to higher spins. Seven new normal-deformed bands, of which three are high-K bands, have been discovered. Neutron alignments were observed in all bands, and the proton alignments observed in several bands at the highest spin region (rotational frequency 0.55 - 0.6 MeV). The results are interpreted within the framework of the cranked shell model (CSM). Intrinsic configurations for the new bands, up to six quasiparticles, are proposed. The co-existing coupling schemes, deformation and rotation alignment, involving identical orbitals at high spin are discussed for the high-K bands. Possible decay pathways associated with three previously proposed candidates for triaxial strongly deformed (TSD) structures in 168Hf have been investigated. The spin and excitation energy of the bandhead for the strongest band, TSD1, were determined approximately based on γ-ray coincidence relationships. Discrete links were established for the second band. The overall agreement between the observed properties of the bands and cranking calculations using the Ultimate Cranker code provides strong support for an interpretation where band TSD1 is associated with a TSD minimum, (ε2, γ) ~ (0.43, 20°), involving the π(i13/2)2 and the ν(j15/2) high-j orbitals. This constitutes the first identification of a TSD band in Hf isotopes, long-predicted by theoretical studies. The second band is understood as being associated with a near-prolate shape and a deformation enhanced with respect to the normal deformed bands. It is proposed to be built on the π(i13/2 h9/2)ν(i13/2)2 configuration. The Doppler-shift attenuation method was used to measure lifetimes of yrast states. The deformation extracted from this measurement fits well with predictions from theoretical calculations.

We investigate the problem how to describe the equivalence classes of formal deformations of a symplectic manifold $M$ in the case when we have several deformation parameters $\ve_1, \ve_2, \dots, \ve_g$ of non-positive degrees. We define formal deformations of $M$ over the base ring $\bbC[[\ve, \ve_1, \dots, \ve_g]]$ as Maurer-Cartan elements of the differential graded Lie algebra $(\ve, \ve_1, \dots, \ve_g) \sPD^\bullet(M)[[\ve, \ve_1, \dots, \ve_g]]$ where $\sPD^\bullet(M)$ denotes the algebra of polydifferential operators on $M$. The interesting feature of such deformations is that, if at least one formal parameter carries a non-zero degree, then the resulting Maurer-Cartan element corresponds to a $\bbC[[\ve, \ve_1, \dots, \ve_g]]$-multilinear $A_\infty$-structure on the graded vector space $\cO(M)[[\ve, \ve_1, \dots, \ve_g]]$ with the zero differential, where $\cO(M)$ is the algebra of smooth complex-valued functions $M$. This dissertation focuses on formal deformations of $\cO(M)$ with the base ring $\bbC[[\ve, \ve_1, \dots, \ve_g]]$ such that corresponding MC elements $\mu$ satisfy these two conditions: The Kodaira-Spencer class of $\mu$ is $\ve \al$ and $\mu$ satisfies the equation $\mu \rvert_{\ve=0} =0$. The main result of this study gives us a bijection between the set of isomorphism classes of such deformations and the set of all degree 2 vectors of the graded vector space \, $\bigoplus_{q \geq 0} \, (\ve, \ve_1, \dots, \ve_g) \, H^q(M, \bbC)[[\ve, \ve_1, \dots, \ve_g]]$ where $H^\bullet(M, \bbC)$ is the singular cohomology of $M$ with coefficients in $\bbC$ and every vector of $H^q(M, \bbC)$ carries degree $q$. / Mathematics

Formality quasi-isomorphisms Cobar(C) -> O are a necessary component of the machinery used in deformation quantization to produce quantized algebras of observables, however they are often constructed via transcendental methods, resulting in computational difficulties and quasi-isomorphisms defined over extensions of Q We will show that these formality quasi-isomorphisms can be "demystified" for a large class of dg-operads, by showing that they can be constructed recursively via an algorithm that builds them from systems of linear equations over Q, given certain assumptions on H(O). / Mathematics

A rapid local deformation of the erythrocyte membrane in the shape of an imprint caused by illumination with a focused laser beam in the presence of an external fluorophore has been investigated. This morphological change of the membrane appeared to be the very first observable step of the photohemolysis process which is exploited in photodynamic therapy. I showed that when a laser beam was focused on the erythrocyte membrane, the membrane was pulled toward the inside of the cell, independently of the direction in which the light was traveling. Imprint formation was observed neither on the lipid membrane of giant unilamellar vesicles nor on the membrane of nucleated mammalian cells such as HeLa cells. It shows that the effect is specific to erythrocytes; suggesting that it might be due to the unique structure of the erythrocyte membrane cytoskeleton. Also, I found that the rate of the imprint formation depended on laser input power, fluorophore concentration, and the presence of oxygen scavenger, but that it was independent of pH in the range pH= 6.4 to 7.8. These dependences are exactly the same for photohemolysis and for the imprint formation. By analogy with the photohemolysis process, these observations suggest that the imprint is created via the oxidization of band 3 proteins on the erythrocyte membrane. It supports the hypothesis that band 3 proteins play a pivotal role in the preservation of the erythrocyte shape. Preliminary work also suggests that spectrin is involved in the imprint formation process. / Thesis / Master of Science (MSc)

Eurokoderna som tillsammans med EKS (Boverkets konstruktionsregler), utgör svenska normer för verifiering av bärförmåga, stadga och beständighet kan ibland vara svåra och tidsödande att tolka och tillämpa i konstruktionsarbetet. I bruksgränstillstånd finns oftast inte krav kvantifierade i eurokoden utan det är byggherrens eller konstruktörens ansvar att formulera dimensioneringskriterier för till exempel deformationer. Denna brist på tydliga krav och definitioner gör det svårt att få en samlad bild och tolkningar och kriterier tenderar till att bli individuella. Hur deformationsgränser och lastfall tolkas och tillämpas påverkar hur byggnadsdelar dimensioneras och utformas och därmed även materialåtgång, kostnad och miljö.   Den här studien är gjord för att effektivisera hur AFRY arbetar med eurokoderna med avseende på bruksgränstillstånd och framför allt vertikala stomdeformationer. Studien visar även hur materialanvändningen påverkas av olika deformationskriterier och lastfall. För att kunna visa detta har några vanligt förekommande konstruktionslösningar studerats.   Det som framkommit är att frånvarandet av deformationsgränser i de svenska eurokoderna är en brist som borde åtgärdas och kanske borde vi göra som andra länder som har med deformationsgränser i den generella delen av eurokoden. Eurokoderna kan även vara krångliga att läsa, och det är lätt att tappa helhetsbilden när informationen som eftersöks finns i olika stycken och eurokoder.   Det har även framkommit att materialåtgången kan vara så stor som 66 procent beroende av hur eurokoderna tolkas och vilka deformationskrav som används. Det är dock en siffra som kan ha stora variationer beroende på konstruktionslösning och material, men resultatet ger dock en fingervisning på hur det kan se ut.