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This study addresses the extent to which participation in the military affects subsequent status attainment and mobility in America. The purpose of this research was to conduct a comprehensive examination of existing empirical research resulting in a synthesis of findings and establishing a concise summary of the state of the literature on this topic. The study is limited to the examination of existing research on male veterans in the years between 1950 and the present. Findings from sixty-four articles and seven books are presented. The background characteristics of servicemen, the promotion and retention of servicemen, and the post-service earnings and education of servicemen, in the era of World War II, Korea, Vietnam, and the All-Volunteer Force are discussed. When possible, comparisons are made between servicemen and their civilian counterparts, as well as between Anglos and African Americans. Findings indicate that men serving in the military prior to Vietnam were from somewhat higher socio-economic and educational backgrounds. The background characteristics of Anglo veterans of Vietnam and the AVF were homogenous to their civilian counterparts. Black veterans of the period from the war in Vietnam through the present have slightly higher levels of education and income prior to service as compared to their civilian counterparts. Research on promotion, retention, and military occupational assignments demonstrate that blacks are more likely to enlist and re-enlist than are Anglos. Promotions are currently achieved at approximately the same rate regardless of race. However, throughout the period examined, blacks are more likely to be trained in military occupational specialties considered to be less transferable to the civilian workforce. Findings on post-service attainment are limited to the examination of income, earnings, and education. Military service resulted in higher levels of income, earnings, and education for all veterans serving since 1950, with the notable exception of Anglo Vietnam veterans. In other words, as compared to their civilian counterparts, veterans had significantly higher incomes, earnings, and educational levels post-service. Explanations for the association between military service and social mobility, including fluctuations in enlistment standards and educational benefits during the period under investigation, are presented. / Ph. D.

In light of rising global temperatures and energy needs, nuclear power is uniquely positioned to offer carbon-free and reliable electricity. In many markets, nuclear power faces strong headwinds due to competition with other fuel sources and prohibitively high capital costs. Small Modular Reactors (SMRs), such as the proposed Advanced Fast Reactor (AFR) 100, have gained popularity in recent years as they promise economies of scale, reduced capital costs, and flexibility of deployment. Fast sodium reactors commonly feature an upper plenum with a large inventory of sodium. When temperatures change due to transients, stratification can occur. It is important to understand the stratification behavior of these large volumes because stratification can counteract natural circulation and fatigue materials. This work features steady-state and transient simulations of thermal stratification and natural circulation of liquid sodium in a simple rectangular slice using a commercial CFD code (ANSYS FLUENT). Different inlet velocities and their effect on stratification are investigated by changing the inlet geometry. Stratification was observed in the two cases with the lowest inlet velocities. An approach for tracking the stratification interface was developed that focuses on temperature gradients rather than differences. Other authors have developed correlations to predict stratification in three dimensional enclosures. However, these correlations predict stratified conditions for all simulations even the ones that did not stratify. The previous models are modified to reflect the two-dimensional nature of the flow in the enclosure. The results align more closely with the simulations and correctly predict stratification in the investigated cases. / Master of Science

This thesis is on molecular dynamics studies of drying suspensions of bidisperse nanoparticle mixtures. I first use an explicit solvent model to investigate how the structure of the dry film depends on the evaporation rate of the solvent and the initial volume fractions of the nanoparticles. My simulation results show that the particle mixtures stratify according to their sizes when the suspensions are quickly dried, consistent with the prediction of recent theories. I further show that stratification can be controlled using thermophoresis induced by a thermal gradient imposed on the drying suspension. To model larger systems on longer time scales, I explore implicit solvent models of drying particle suspensions in which the solvent is treated as a uniform viscous background and the liquid-vapor interface is replaced by a potential barrier that confines all the solutes in the solution. Drying is then modeled as a process in which the location of the confining potential is moved. In order to clarify the physical foundation of this moving interface method, I analyze the meniscus on the outside of a circular cylinder and apply the results to understand the capillary force experienced by a spherical particle at a liquid-vapor interface. My analyses show that the capillary force is approximately linear with the displacement of the particle from its equilibrium location at the interface. An analytical expression is derived for the corresponding spring constant that depends on the surface tension and lateral span of the interface and the particle radius. I further show that with a careful mapping, both explicit and implicit solvent models yield similar stratification behavior for drying suspensions of bidisperse particles. Finally, I apply the moving interface method based on an implicit solvent to study the drying of various soft matter solutions, including a solution film of a mixture of polymers and nanoparticles, a suspension droplet of bidisperse nanoparticles, a solution droplet of a polymer blend, and a solution droplet of diblock copolymers. / PHD / Drying is a ubiquitous phenomenon. In this thesis, I use molecular dynamics methods to simulate the drying of a suspension of a bidisperse mixture of nanoparticles that have two different radii. First, I use a model in which the solvent is included explicitly as point particles and the nanoparticles are modeled as spheres with finite radii. Their trajectories are generated by numerically solving the Newtonian equations of motion for all the particles in the system. My simulations show that the bidisperse nanoparticle mixtures stratify according to their sizes after drying. For example, a “small-on-top” stratified film can be produced in which the smaller nanoparticles are distributed on top of the larger particles in the drying film. I further use a similar model to demonstrate that stratification can be controlled by imposing a thermal gradient on the drying suspension. I then map an explicit solvent system to an implicit one in which the solvent is treated as a uniform viscous background and only the nanoparticles are kept. The physical foundation of this mapping is clarified. I compare simulations using the explicit and implicit solvent models and show that similar stratification behavior emerge in both models. Therefore, the implicit solvent model can be applied to study much larger systems on longer time scales. Finally, I apply the implicit solvent model to study the drying of various soft matter solutions, including a solution film of a mixture of polymers and nanoparticles, a droplet of a bidisperse nanoparticle suspension, a solution droplet of a polymer blend, and a droplet of a diblock copolymer solution.

Ye / Genetic and epigenetic alterations significantly contribute to development of human cancer. Genotyping tumour tissue in search for these actionable genetic and epigenetic changes has become routine practice in oncology. However, sampling tumour tissue has significant inherent limitations. It provides only a single snapshot in time, prone to selection bias due to intra-tumour heterogeneity, and cannot always be performed owing to its invasive nature. Circulating tumour DNA (ctDNA) based liquid biopsy provides an effective alternative to invasive tissue sampling and have emerged as a minimally invasive, real-time biomarker. Recent advancements in DNA sequencing technologies have revealed enormous potential of ctDNA to improve tumour detection and stratification. In this review, we critically appraise the role of ctDNA as a liquid biopsy for cancer and evaluate the role of circulating tumour DNA as a diagnostic, prognostic and predictive biomarker. We also highlight some technical challenges and constraints associated with circulating DNA analysis.

Yes / Results are presented from a numerical simulation to investigate the vertical buoyant wall jet discharged into a linearly stratified environment. A tracer transport model considering density variation is implemented. The standard k-ε model with the buoyancy effect is used to simulate the evolution of the buoyant jet in a stratified environment. Results show that the maximum jet velocity trend along vertical direction has two regions: acceleration region and deceleration region. In the deceleration region, jet velocity is reduced by the mixing taking place between jet fluid and ambient lighter fluid. Jet velocity is further decelerated by the upwards buoyant force when ambient fluid density is larger than jet fluid density. The normalized peak value of the cross sectional maximum jet velocity decreases with λ (the ratio between the characteristic momentum length and the buoyancy length). When λ<1, the dimensionless maximum penetration distance (normalized by the characteristic buoyancy length) does not vary much and has a value between 4.0 and 5.0, while it increases with increasing λ for λ≥1. General good agreements between the simulations and measurements are obtained, indicating that the model can be successfully applied to investigate the mixing of buoyant jet with ambient linearly stratified fluid. / Engineering and Physical Sciences Research Council (EPSRC: EP/G066264/1), National Natural Science Foundation of China (51609214,41376099,51609213), National Natural Science Foundation for Distinguished Young Scholars of China (Grant No.51425901),Public Project of Zhejiang Province (2016C33095)

Ce travail comporte deux parties dont la première concerne l'ensemble asymptotique $S_F$ d'une application polynomiale $F: C^n to C^n$. Dans les année 90s, Jelonek a montré que cet ensemble est une variété algébrique complexe singulière de dimension (complexe) $n-1$. Nous donnons une méthode, appelée {it méthode des fa{c c}ons}, pour stratifier cet ensemble. Nous obtenons une stratification de Thom-Mather. Par ailleurs, il existe une stratification de Whitney de $S_F$ telle que l'ensemble des fa{c c}ons possibles soit constant sur chaque strate. En utilisant les fa{c c}ons, nous donnons un algorithme pour expliciter l'ensemble asymptotique d'une application quadratique dominante en trois variables. Nous obtenons aussi une liste des ensembles asymptotiques possibles dans ce cas. La deuxième partie concerne l'ensemble $V_F$ : En 2010, Anna et Guillaume Valette ont construit une pseudo-variété réelle $V_F subset R^{2n + p}$, où $p > 0$, associée à une application polynomiale $F: C^n to C^n$. Dans le cas $n = 2$, ils ont prouvé que si $F$ est une application polynomiale de déterminant jacobien partout non nul, alors $F$ n'est pas propre si et seulement si l'homologie d'intersection de $V_F$ n'est pas triviale en dimension 2. Nous donnons une généralisation de ce résultat, dans le cas d'une application polynomiale $F : C^n to C^n$ de jacobien partout non nul. Nous donnons aussi une méthode pour stratifier l'ensemble $V_F$. Comme applications, nous obtenons des stratifications de l'ensemble des valeurs critiques asymptotiques de $F$ et de l'ensemble des points de bifurcation de $F$. / There are two parts in the present work. The first part concerns the asymptotic set of a polynomial mapping $F: C^n to C^n$. In the 90s, Zbigniew Jelonek showed that this set is a $(n-1)$ - (complex) dimensional singular variety. We give a method, called {it m'ethode des fa{c c}ons}, for stratifying this set. We obtain a Thom-Mather stratification. Moreover, there exists a Whitney stratification such that the set of possible fa{c c}ons is constant on every stratum. By using the fa{c c}ons, we give an algorithm for expliciting the asymptotic sets of a dominant quadratic polynomial mapping in three variables. As a result, we have a complete list of the asymptotic sets in this case. The second part concerns the set called Valette set $V_F$. In 2010, Anna and Guillaume Valette constructed a real pseudomanifold $V_F subset R^{2n + p}$, where $p > 0$, associated to a polynomial mapping $F: C^n to C^n$. In the case $n = 2$, they proved that if $F$ is a polynomial mapping with nowhere vanishing Jacobian, then $F$ is not proper if and only if the homology (or intersection homology) of $V_F$ is not trivial in dimension 2. We give a generalization of this result, in the case of a polynomial mapping $F : C^n to C^n$ with nowhere vanishing Jacobian. We give also a method for stratifying the set $V_F$. As applications, we have the stratifications of the set of asymptotic critical values of $F$ and the set of bifurcation points of $F$.

On constate que la majorité des essais de phase III, conduits après des essais de phase II pourtant prometteurs, sont “négatifs”, la nouvelle thérapeutique se révélant finalement trop toxique ou insuffisamment efficace. L’hétérogénéité de la population participant aux différentes phases de développement est une explication. Elle induirait une estimation erronée de la toxicité et, par dilution de l’effet traitement, conduirait à arrêter l’évaluation thérapeutique alors que peut être un sous-ensemble de cette population, définie à partir d’une caractéristique particulière, pourrait en bénéficier.Dans cette thèse, nous proposons dans un premier temps une réflexion sur les aspects méthodologiques des essais de phase II qui permettraient d’améliorer l’identification précoce des thérapeutiques toxiques et des populations les plus sensibles et donc de ne planifier des essais de phase III que sur des populations encore mieux ciblées. Dans un second temps, nous présentons une nouvelle méthodologie d’essai de phase II que nous avons développée pour prendre en compte l’hétérogénéité de la population et son intérêt en pratique clinique courante. Avec cette méthode, qui est une extension du plan de Fleming à deux étapes, le développement des médicaments est moins fréquemment arrêté pour la population entière et moins de patients non sensibles à la nouvelle thérapeutique sont exposés à des molécules potentiellement toxiques, durant l’étape 2 de l’essai de phase II ou plus tard lors de l’essai de phase III. / The majority of phase III clinical trials, despite being conducted after promising phase II trials, are "negative," with the new therapy determined in the end to be too toxic or insufficiently efficacious. One explanation is the heterogeneity of the populations participating in various phases of development, which results in an erroneous estimation of the toxicity and thus a diluted therapeutic effect. This may lead to termination of evaluation of a therapy, even if a sub-population, defined by a particular characteristic, may stand to benefit from it. In this thesis, we propose a close examination of the methodological aspects of phase II trials which would permit improved early identification of toxic therapies and of responsive populations, so that phase III trials may be designed only with the best targeted populations in mind. We present as well a new phase II clinical trial methodology which we have developed to take into account trial population heterogeneity and its importance in current clinical practice. With this method, drug development is less often stopped for the entire phase II population and less non sensitive patients are exposed to toxic drugs in the second part of phase II trials, and next in phase III trials.