Phase separation behavior in a rubber-toughened epoxy system

Four series of epoxy resins were cured in the presence of a carboxyl-terminated butadiene acrylonitrile (CTBN). The first two series consisted of 7 components, in which the epoxy, hardener, and rubber form one network and two methacrylates form a second interpenetrating, interconnected network. The variables explored are the initial composition of rubber and the ratio of the two methacrylates. The last two series consist of only 3 components, epoxy, hardener, and rubber. The only variable in each is the rubber concentration. The cure schedule for all the samples was the same. The final size of the rubber particles in each sample were measured using optical microscopy (OM) and scanning electron microscopy (SEM). The impact strength of the seven component samples was measured using an Izod impact tester. Particles were not seen in OM for the first two series and only one rubber concentration value in the second two. SEM on etched samples confirmed the presence of particles formed by nucleation and growth in all the samples. The SEM confirmed the OM results of 8.5 and 9 μm domain sizes for the two samples that showed optically. Phase separation was seen in the 7 component series up to 16% rubber in the first and 10% in the second and rubber particles were measured at 0.75-3 μm in size. The Izod results showed an apparent increase in toughness with increasing rubber concentration and no clear dependence on particle size or size distribution, though the error was so large that the true effect of the presence of particles cannot be confirmed

Algorithms for operations on probability distributions in a computer algebra system

In mathematics and statistics, the desire to eliminate mathematical tedium and facilitate exploration has lead to computer algebra systems. These computer algebra systems allow students and researchers to perform more of their work at a conceptual level. The design of generic algorithms for tedious computations allows modelers to push current modeling boundaries outward more quickly.;Probability theory, with its many theorems and symbolic manipulations of random variables is a discipline in which automation of certain processes is highly practical, functional, and efficient. There are many existing statistical software packages, such as SPSS, SAS, and S-Plus, that have numeric tools for statistical applications. There is a potential for a probability package analogous to these statistical packages for manipulation of random variables. The software package being developed as part of this dissertation, referred to as A Probability Programming Language (APPL) is a random variable manipulator and is proposed to fill a technology gap that exists in probability theory.;My research involves developing algorithms for the manipulation of discrete random variables. By defining data structures for random variables and writing algorithms for implementing common operations, more interesting and mathematically intractable probability problems can be solved, including those not attempted in undergraduate statistics courses because they were deemed too mechanically arduous. Algorithms for calculating the probability density function of order statistics, transformations, convolutions, products, and minimums/maximums of independent discrete random variables are included in this dissertation

Alzheimer’s Disease: More Than Just Memory Loss: An Awareness of the Disease and an Active Plan of Coping Strategies and Caregiving

Alzheimer’s Disease (AD) is a chronic neurodegenerative disease which leads to progressive mental deterioration that can occur in middle or old age. During the disease’s progression, various biochemical functions of the brain cells go astray and eventually lead to memory loss. What a lot of people do not always realize is the fact this disease goes beyond just losing memory. From my own observation as well as research studies, it has been noted that AD patients can experience sleep disruption, sundowning, speech decline, apraxia, agnosia, and behavioral changes such as depression and combativeness. As more of these signs and symptoms become evident to me, I conducted a plan as to how people who have loved ones with Alzheimer’s Disease can cope with them and those who experience the disease themselves can learn to improve everyday functions as the disease progresses. This thesis constitutes an awareness of all aspects of Alzheimer’s and a compilation of the best method for treatment and prevention

Timing of exhumation of the eastern Central Alps from zircon and apatite (U-Th)/He thermochronology (Graubünden, Switzerland)

The structurally complex eastern Central Alps, located in eastern Switzerland and adjacent areas, have helped constrain the timing and kinematics of deformation during the Alpine orogeny. Several regional and orogenic scale studies have established a well-defined structural evolution of the eastern Central Alps; however, the low-temperature cooling history of the region remains relatively unconstrained. An understanding of this cooling history may elucidate mechanisms for exhumation of the region and evaluate orogenic scale models for the timing and nature of exhumation within the mountain belt. This study presents new low-temperature zircon and apatite (U-Th)/He age data from the Austroalpine and Penninic nappes of the eastern Central Alps that reveals a three stage cooling history for the region. These data, combined with inverse time-temperature modeling, provide cooling rates for the three phase history. Slow cooling at rates of ~1-10 °C/m.y. through the zircon HePRZ (~200-140 °C) are recorded in the Austroalpine Silvretta, Campo-Grosina, and Err nappes during the Eocene from ~52 to 36 Ma. This period of cooling is related to exhumation resulting from north directed thrusting associated with continental collision. A second stage of rapid cooling at rates of 10-50 °C/m.y. from ~36 to 21 Ma, are recorded by zircon and apatite (U-Th)/He age data from the Bernina and Corvatsch Austroalpine nappes, and zircon (U-Th)/He age data from Penninic units exposed in the Engadine Window. This period of relatively rapid cooling and exhumation is likely a response to a combination of backthrusting along the Insubric Line and crustal duplexing at depth. A final period of cooling and exhumation is recorded only in the Silvretta Austroalpine nappe and Penninic units exposed in the Engadine Window at ~16 Ma. This period of cooling and exhumation is likely a result of uplift along the oblique left-lateral Engadine Line. The overall cooling history of the eastern Central Alps shows that the western exposure of the orogenic lid behaved as a rigid to semi-rigid block during continental collision and continued convergence until the Engadine Line affected the region in the Miocene. The three phase cooling history constrained by this low-temperature thermochronometric data contributes to the growing body of evidence for episodic cooling and apparent exhumation of the Alpine orogen

Women of the future : gender, technology, and cyborgs in Frank Herbert's dune

Cette thèse défend les mérites d’une lecture cyborgienne de l’oeuvre de science-fiction de Frank Herbert, Dune, où la vision particulière des sciences et technologies nous permet d’interpréter plusieurs personnages en tant que réitération Nouvelle Vague du cyborg. Publié en 1965, Dune introduit des personnages féminins atypiques pour cette époque compte tenu de leurs attributs tels qu’une capacité intellectuelle accrue, une imposante puissance de combat et une immunité manifeste contre la faiblesse émotionnelle. Cependant, le roman reste ambivalent en ce qui concerne ces femmes : en dépit de leurs qualités admirables, elles sont d’autre part caractérisées par des stéréotypes régressifs, exposants une sexualité instinctive, qui les confinent tout au mieux aux rôles de mère, maitresse ou épouse. Finalement, dans le roman, elles finissent par jouer le rôle du méchant. Cette caractérisation se rapproche beaucoup de celle du cyborg femelle qui est d’usage courant dans les productions de science fiction pour le grand public des décennies plus récentes. Par conséquent, cette thèse défend qu’une lecture cyborgienne de Dune complète et accroisse une analyse sexospécifique, car cette approche comporte une théorisation essentielle des réactions à l’égard de la technologie qui, selon Evans, sont entretissées dans la réaction patriarcale de ce roman à l’égard des femmes. Bien que ces créatures fictives ne soient pas encore communes à l’époque de la rédaction de Dune, Jessica et certains autres personnages du roman peuvent néanmoins être considérés comme exemples primitifs des cyborgs, parce qu’ils incarnent la science et la technologie de leur culture et qu’ils possèdent d’autres éléments typiques du cyborg. L’hypothèse propose que la représentation des femmes dans Dune ne découle pas seulement de l’attrait pour le chauvinisme ou la misogynie, mais qu’elle est en fait grandement influencée par la peur de la technologie qui est transposée sur la femme comme c’est couramment le cas dans la littérature cyborg subséquente. Ainsi, ce roman annonce le futur sous-genre cyborg de la science-fiction.Evans argues for the merits of a cyborgian reading of Frank Herbert’s seminal science fiction novel, Dune, on the basis that the novel’s particular conception of science and technology allows many of the characters to be understood as New Wave iterations of the cyborg. First published in 1965, Dune includes female characters uncharacteristic for the genre during this period due to the degree of their intelligence, formidable fighting powers, and seeming freedom from emotional weakness. However, the novel is ambivalent about its super-women: despite their admirable qualities, they are otherwise depicted in retrogressive stereotypes, representing the instinctual sex, naturally best limited to roles of mothers, lovers, and wives; by the novel’s conclusion they are cast as villains. This particular characterization of women shares many qualities with the trope of the female cyborg that becomes common in mass media science fiction of later decades. Therefore, this thesis argues that a cyborgian reading of Dune complements and augments a gender analysis of the novel because this approach incorporates an essential theorization of the reactions to technology that, according to Evans, are interwoven into the novel’s patriarchal response to women. Although these fictional creatures were not yet common at the time of Dune’s writing, Jessica and other characters in the novel can be read nonetheless as early examples of cyborgs because they physically embody their culture’s science and technology, and are consistent with other important hallmarks of the figure. The argument is that Herbert’s depiction of women in Dune does not just arise from an appeal to male chauvinism and misogyny, but is, in fact, strongly influenced by a fear of technology that is projected onto women, as is commonly seen in later cyborg literature. According to such a reading, the novel foreshadows the later cyborg sub-genre of science fiction

Bicultural Appalachian Females: The Mediating Effect of Perceived Stigma on Health Outcomes

Appalachia has been the focus of ongoing curiosity and ascribed disdain in Euro-centric American history. An amalgamation of cultures found a home in the Appalachian Mountains, blending to create a unique collectivistic culture still visible today. However, this culture has often been misconstrued as unhealthy or undesirable at best and, by reductionistic intentions, relegated to a culture of poverty. Within this system, Appalachian females have faced the burden of the intersectionality of their identities, given the acculturation expectations and Appalachian identity stigma imposed by the dominant Euro-North American culture. As indicated in scholarly literature, despite chronic marginalization and systemic oppression, a silent minority still retains the core elements of its heritage culture. However, it remains hidden by a bicultural approach that bridges the gap between identifying as Appalachian and American. This study hypothesized that perceived stigma directly impacts the overall physical and mental health outcomes of women who identify as culturally Appalachian. The degree of bicultural expression was assumed to affect the strength of the relationship between perceived stigma and health outcomes