Our aim was to aid the viscoelasticity into the model for thermal convection by developing our own code in Fortran 90 and to study the role of viscoelasticity in this model. We should have included the viscoelasticity by Maxwell model; however, due to numerical instability we changed it for Oldroyd-B model. We were adding the terms of objective derivative into our code step by step and we were observing how they influence the behaviour of thermal convection. Partial time derivative and advective terms were included in whole complexity, the corrotational terms need more numerical testing. Our work suggest that the influence of viscoelasticity on thermal convection is noticeable. Powered by TCPDF (www.tcpdf.org)

Numerical simulations of the complex flows of complex (viscoelastic) fluids are investigated. The primary fluid investigated in this thesis is human blood, a complex fluid which can be modelled via viscoelastic constitutive models. The most commonly used constitutive models for viscoelastic fluids include the OldroydB, Giesekus, Johnson-Segalman, Finitely Extensible Non-Linear Elastic (FENE), Phan-Thein-Tanner (PTT) models etc. Our Numerical approach is based on the finite volume methods implemented on the OpenFOAM platform. We employ the Giesekus, Oldroyd-B, and Generalized Oldroyd-B viscoelastic constitutive models in this thesis, depending on the underlying context. Numerical validation of our results is conducted via the most used benchmark flow problems for viscoelastic fluid flow. The robust and efficient numerical methodologies are then deployed to investigate the flow characteristics, and hence illustrate various novel behavior, for blood flow in stenosed and bifurcated arteries. The present work took advantage of the availability of a reasonable set of viscoelastic constitutive model solvers within OpenFOAM, specifically the viscoelasticFluidFoam solver which we modified and developed to suit our focused needs for blood flow computations. The modified computational algorithms were successfully validated against well-known benchmark flow problems in the literature. Noting that the Giesekus viscoelastic constitutive model is a generalization of both the Oldroyd-B and Generalized Oldroyd-B models, the validation of results is carried out via the Giesekus model enabling us to develop a general-purpose code capable of simulating several viscoelastic constitutive models. The main results were otherwise presented for the Oldroyd-B and Generalized Oldroyd-B models as these are the most applicable to blood flow modelling. The results demonstrate that the velocity spurt through the stenosis is directly proportional to the constriction caused by the stenosis. The higher the blockage from the constriction, the higher the corresponding velocity spurt through the constriction. This velocity behavior, as the constriction blockage increases, correspondingly increase the wall shear stresses. High wall shear stresses significantly increase the possibility of rupture of the stenosis/blockage. This can lead to catastrophic consequences in the usual case where the stenosis is caused by tumor growth.

Three-Dimensional (3D) integration of circuits based on die and wafer stacking using through-silicon-via is a critical technology in enabling "more-than-Moore", i.e. functional integration of devices beyond pure scaling ("more Moore"). In particular, the scaling from multi-core to many-core architecture is an excellent candidate for such integration. 3D systems design follows is a challenging and a complex design process involving integration of heterogeneous technologies. It is also expensive to prototype because the 3D industrial ecosystem is not yet complete and ready for low-cost mass production. Networks-on-Chip (NoCs) efficiently facilitates the communication of massively integrated cores on 3D many-core architecture. In this thesis scalability and performance issues of NoCs are explored in terms of architecture, organization and functionality of many-core systems. First, we evaluate on-chip network performance in massively integrated many-core architecture when network size grows. We propose link and channel models to analyze the network traffic and hence the performance. We develop a NoC simulation framework to evaluate the performance of a deflection routing network as the architecture scales up to 1000 cores. We propose and perform comparative analysis of 3D processor-memory model configurations in scalable many-core architectures. Second, we investigate how the deflection routing NoCs can be designed to maximize the benefit of the fast TSVs through clock pumping techniques. We propose multi-rate models for inter-layer communication. We quantify the performance benefit through cycle-accurate simulations for various configurations of 3D architectures. Finally, the complexity of massively integrated many-core architecture by itself brings a multitude of design challenges such as high-cost of prototyping, increasing complexity of the technology, irregularity of the communication network, and lack of reliable simulation models. We formulate a zero-load average distance model that accurately predicts the performance of deflection routing networks in the absence of data flow by capturing the average distance of a packet with spatial and temporal probability distributions of traffic. The thesis research goals are to explore the design space of vertical integration for many-core applications, and to provide solutions to 3D technology challenges through architectural innovations. We believe the research findings presented in the thesis work contribute in addressing few of the many challenges to the field of combined research in many-core architectural design and 3D integration technology. / <p>QC 20151221</p>

The Landau-Ginzburg (LG) B-Model is a significant feature of singularity theory and mirror symmetry. Krawitz in 2010, guided by work of Kaufmann, provided an explicit construction for the LG B-model when using diagonal symmetries of a quasihomogeneous, nondegenerate polynomial. In this thesis we discuss aspects of how to generalize the LG B-model construction to allow for nondiagonal symmetries of a polynomial, and hence nonabelian symmetry groups. The construction is generalized to the level of graded vector space and the multiplication developed up to an unknown factor. We present complete examples of nonabelian LG B-models for the polynomials x^2y + y^3, x^3y + y^4, and x^3 + y^3 + z^3 + w^2.

The goal of this thesis is to investigate a conjecture about Mirror Symmetry for Landau Ginzburg (LG) models with non-abelian gauge groups. The conjecture predicts that the LG A-model for a polynomial-group pair $(W,G)$ is equivalent to the LG B-model for the dual pair $(W^*, G^*)$. In particular, the A-model and B-model include the construction of a Frobenius algebra. The LG mirror symmetry conjecture predicts that the A-model Frobenius algebra for $(W,G)$ will be isomorphic to the B-model Frobenius algebra for the dual pair $(W^*,G^*)$. Part of the conjecture includes a rule describing how to construct the dual pair. Until now, no examples of this phenomenon have been verified. In this thesis we will verify the conjecture for the polynomial $W(x_1,x_2,x_3,x_4) = x_1^4+x_2^4+x_3^4+x_4^4$ with a maximal admissible non-abelian group. I present a supplementary guide along with a worked example to compute the state spaces of each of the A and B models with non-abelian groups. This includes formalizing G-actions to take invariants, computing each state space, formalizing the product on each state space, and as the main result, showing there indeed exists an isomorphism of Graded Frobenius Algebras between the LG A-model and dual LG B-model.

In this work, we develop a method for solving viscoelastic fluid flows using the Navier-Stokes equations coupled with the Oldroyd-B model. We solve the Navier-Stokes equations in skew-symmetric form using the mixed finite element method, and we solve the Oldroyd-B model using the discontinuous Galerkin method. The Crank-Nicolson scheme is used for the temporal discretization of the Navier-Stokes equations in order to achieve a second-order accuracy in time, while the optimal third-order total-variation diminishing Runge-Kutta scheme is used for the temporal discretization of the Oldroyd-B equation. The overall accuracy in time is therefore limited to second-order due to the Crank-Nicolson scheme; however, a third-order Runge-Kutta scheme is implemented for greater stability over lower order Runge-Kutta schemes. We test our numerical method using the 2D cavity flow benchmark problem and compare results generated with those found in literature while discussing the influence of mesh refinement on suppressing oscillations in the polymer stress. / Master of Science / Viscoelastic fluids are a type of non-Newtonian fluid of great importance to the study of fluid flows. Such fluids exhibit both viscous and elastic behaviors. We develop a numerical method to solve the partial differential equations governing viscoelastic fluid flows using various finite element methods. Our method is then validated using previous numerical results in literature.

Yes / Co-production and active participation of the consumers are considered to have enhanced the value co-creation activities that would ensure business benefits of a firm. The marketing literature available does not explicitly explain the philosophy that would motivate the consumers to help to increase values for co-creation activities. In this context, attempts have been made to identify the factors that would impact on co-production and consumers’ participation to co-create values. By studying literature and theories such as theory of co-creation, theory of value creation, information processing theory, marketing theory and expectancy value theory, a conceptual model called F-P-C-B (Future Participation (F) - Co-production (P) - Co-creation (C) - Business Benefit (B)) has been developed along with nine hypotheses. The data was from 362 respondents in India and the model was tested using PLS based analysis. The study shows that it is important for the firms to shift from product-oriented activities to customer-related strategies. It is also found that for obtaining more profitability and better business results, customers should be involved in business activities by way of involving in co-design, idea generation, and other relevant activities of the firms. Moreover, the study highlights that knowledge sharing between the customers and the firm authorities ensures better business values.

The main focus of this work is on the non-Newtonian effects on the inertial instabilities in shear flows. Both inelastic (Carreau) and elastic models (Oldroyd-B and FENE-P) have been employed to examine the main features of the non-Newtonian fluids; shear-thinning, shear-thickening and elasticity. Several classical configurations have been considered; flow past a circular cylinder, in a lid-driven cavity and in a channel. We have used a wide range of tools for linear stability analysis, modal, non-modal, energy and sensitivity analysis, to determine the instability mechanisms of the non-Newtonian flows and compare them with those of the Newtonian flows. Direct numerical simulations have been also used to prove the results obtained by the linear stability analysis. Significant modifications/alterations in the instability of the different flows have been observed under the action of the non-Newtonian effects. In general, shear-thinning/shear-thickening effects destabilize/stabilize the flow around the cylinder and in a lid driven cavity. Viscoelastic effects both stabilize and destabilize the channel flow depending on the ratio between the viscoelastic and flow time scales. The instability mechanism is just slightly modified in the cylinder flow whereas new instability mechanisms arise in the lid-driven cavity flow. We observe that the non-Newtonian effect can alter the inertial flow at both baseflow and perturbation level (e.g. Carreau fluid past a cylinder or in a lid driven cavity) or it may just affect the perturbations (e.g. Oldroyd-B fluid in channel). In all the flow cases studied, the modifications in the instability dynamics are shown to be strongly connected to the contribution of the different terms in the perturbation kinetic energy budget. / <p>QC 20140113</p>

Food waste is an arguably increasing problem in society, with consumers being responsible for as much as half of all combined food waste. The problem needs to be tackled from all angles, but there is no all encompassing solution for all situations. One context consumers find themselves in is the kitchen at their place of work, where the shared nature of the refrigerator creates situations and problems not found in the home environment. It is for these shared kitchens that this study is focused on providing a physical solution based on The Behavioural Change Wheel (BCW), book providing methods and tools for designing with the goal of behavioural change. The intention of this study was to develop, test and later evaluate a prototype on its behavioural change capacity and potential, using the tools presented in the BCW. The developed prototype took form as an RFID activated labelling system, providing users with the current date and their name on a label to be adhered on the articles they place in the shared refrigerator. After the testing period, an online questionnaire was sent out and was answered by fourteen out of seventeen participants. The two week testing period and subsequent questionnaire provided no conclusive answers regarding detected behavioural change capacity, but the potential is considered high based on participants qualitative comments and attitudes, and their quantitative usage. No measurements of change in food waste is conducted, but the target behavioural changes would provide a positive development resulting in less food waste in the workplace kitchen, if not only a more orderly refrigerator. / Matavfall är ett påtagligt ökande problem i samhället, där konsumenter ansvarar för så mycket som hälften av allt kombinerat matavfall. Problemet bör hanteras från alla möjliga håll, men det finns ingen allmän lösning för alla situationer. Ett sammanhang som konsumenterna befinner sig i är köket på deras arbetsplats, där kylskåpets gemensamma natur skapar situationer och problem som inte återfinns i hemmiljön. Det är för dessa delade kök som denna studie riktar sig på att tillhandahålla en fysisk lösning baserad på The Behavioural Change Wheel (BCW). Den innehåller metoder och verktyg för att designa med beteendeförändring som mål. Syftet med denna studie var att utveckla, testa och senare utvärdera en prototyp angående dess beteendeförändringsförmåga och potential, med hjälp av de verktyg som presenteras i BCW. Den färdigställda prototypen tog form som ett RFID-aktiverat etikettsystem, som gav användarna det aktuella datumet och deras namn på en etikett som ska sättas på artiklarna som de placerar i det delade kylskåpet. Efter testperioden skickades ett frågeformulär ut och fjorton av sjutton deltagare svarade. En testperiod på två veckor och efterföljande frågeformulär gav inga avgörande svar angående påvisad beteendeförändringsförmåga, men potentialen anses vara hög baserad på deltagarnas kvalitativa kommentarer och attityder, och deras kvantitativa användning. Inga mätningar kring mängd matavfall utfördes, men målbeteendeförändringarna skulle ge en positiv utveckling som resulterar i mindre matavfall i arbetsplatsens kök, om inte bara ett mer ordnat kylskåp. / Smart storage solutions in the fridge of the future to reduce food waste

本研究主要目的係探索大台北地區消費者對義大利、日本、中華民國、韓國、美國等 國家的服飾產品態度。並瞭解消費者的自我意議高低、購買及使用經驗多寡與消費者 態度間的關係。 第一章緒論首先敘述本研究的背景及動機。第二節說明本研究的範圍、包括產品、國 家別、樣本的選取等，第三節則闡述本研究所欲達成的目的為何? 第四節根據研究的 自變項、應變項來說明研究的假設。 第二章敘述與本研究有關的理論及文獻探討，第一節為消費者行為理論，包括消費者 行為模式E–K–B Model， 有關態度方面的相關理論。第二節為相關研究文獻探討， 分別討論過去學者研究的問題及發現。第三節則摘要本國學者的一些相關研究及發現 。 第三章主要在說明研究方法，對研究的內容作－扼要性的報告。第一節說明研究流程 ，第二節則根據理論，將本研究的觀念架構加以表達。第三節報告研究的設計重點， 第四節為問卷設計的說明。第五節抽樣方法則討論樣本的選取，資料的收集方法。第 六節為研究資料的分析方法。 第四章首先說明抽樣的結果包括全體樣本對各國服飾產品態度的平均數及標準差、各 種人口統計變項的交叉分析表、消費者自我意識、購買及使用經驗；最後說明消費者 對服飾產品的認知及訊息來源。 第五章說明運用統計方法變異數分析分析消費者對不國家態度差異以及不同消費者群 體差異，並檢定研究所做假設。第六章則說明研究的結論以及在市場行銷上的涵義。