Alumni Dissertations

 

Alumni Dissertations

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  • Continuum and Molecular Dynamics Simulations of the Growth of a Vapor Bubble on a Heating Surface: Exploring the Mechanism of Nucleate Boiling Heat Transfer

    Author:
    Jinyong Bao
    Year of Dissertation:
    2011
    Program:
    Engineering
    Advisor:
    David Rumschitzki
    Abstract:

    Starting with a completely rewritten code for the conductively-driven quasi-static vapor bubble growth in an axisymmetric, cylindrical cell comprised of solid and liquid phase of finite thicknesses under small Reynolds, Peclet, Capillary and Bond numbers to verify L. Huang's (our prior Ph.D. student) earlier results, we couple the solution of the quasi-static problem with three simple, somewhat ad hoc models of contact line motion and relax the assumption of small Bond number to simulate the growth of an incipient bubble until gravity begins to slowly deform the vapor bubble and then to detach it from the solid heater surface. A simple physical theory is developed to explain that when the bubble density is not too high, the bubble volume vs time approaches a 3/2 power before gravity begins to deform its shape, independent of contact line motion models and system parameters such as the conductivity ratio of the liquid to solid and degree of wall superheat. On the other hand, contact line motion does have a significant effect on bubble deformation and detachment. Molecular dynamics (MD) is employed to determine the contact line motion in a nano-scale version of our three-phase system because MD not only includes heat transfer, but also fluid flow, which can remove many restrictions of the earlier continuum calculation in our nano-size system. Instead of nucleating a bubble by cavitation, we nucleate a vapor bubble by heating the bottom of the solid upon which the fluid sits at constant pressure. Under a uniform body force that, due to the scale of MD is far larger than terrestrial gravity, we then track the bubble's growth driven by heat transfer from the conducting heated solid until detachment. Its contact line motion is monitored and the effects of wettability of solid surface, temperature-slip of fluid-solid interface and the choice of the interaction between the solid and the fluid have also been discussed. Unfortunately, this temperature slip mitigates some of the effects of the contact line that the continuum modeling (without temperature slip) finds so crucial at macroscopic scales.

  • Neocontradictions: The Politics and Ideology of American Welfare State Decline

    Author:
    Darren Barany
    Year of Dissertation:
    2009
    Program:
    Sociology
    Advisor:
    Stanley Aronowitz
    Abstract:

    This study historically investigates the circumstances - economic, political, and ideological - out of which the American political culture would shift to the right and become hostile to welfare. It is in part a genealogy of contemporary welfare reform discourse, which is comprised by the synthesis of varied and contradictory components of conservative philosophy about family, work, responsibility, and the role of government. This study also contextualizes that discourse within the development of a conservative politico-ideological apparatus. Today's conservative movement in the United States is the fusion of other sub-strands of conservatism and has successfully defined the parameters of acceptable discourse around the issue of welfare. It has developed a large pool of resources, become adept in the arena of activist and electoral politics, built a vast infrastructure for the production and deployment of ideas, and established a resilient presence in the everyday lives of Americans. Therefore a study of the erosion of the American welfare state must trace the development of these ideas and the means by which they became policy orthodoxy. Argued here is that the conservative movement's success in affecting welfare reform can be attributed to two factors. Firstly, it can be attributed to the consolidation and organization of libertarian and traditionalist conservatism and to the mastery of ideological production by a conservative politico-ideological apparatus or policy planning network. Secondly, it can be attributed to the emergence of varied conservative ideas on work, family, equality, and personal responsibility as a new policy consensus which was itself a consequence of important transformations in social and economic conditions. The post-war conservative movement has been dynamic and has managed its own ideological tensions by continually refining its argument and perfecting its methods of framing issues. It has contributed to altering the political culture in relation to the welfare state and related issues The subjection of welfare state programs to ongoing critique has enabled the social safety net to become vulnerable to reforms which have gradually altered them to be more consistent with the shifting requirements of the economic system and elite preferences.

  • An Examination of Predictive Variables of Success in Mental Health Diversion Programs.

    Author:
    Virginia Barber Rioja
    Year of Dissertation:
    2009
    Program:
    Psychology
    Advisor:
    Thomas Kucharski
    Abstract:

    Diversion programs were developed to ease the overrepresentation of individuals with psychiatric disorders in the criminal justice system. These programs divert individuals with mental illnesses out of jails into community treatment. Despite the increased popularity of these programs, little is known about the psychosocial, psychiatric and psychological characteristics of the diverted individuals. In addition, despite the importance of using standardized assessment instruments pre-diversion, no published study has attempted to evaluate the utility of risk assessment instruments or measures of malingering, personality or psychopathology in diverted offenders. This investigation attempted to address this gap in the literature through three different studies that (1) described a sample of 61 defendants released from jail in terms of demographical, clinical, and criminological characteristics; (2) determined the utility of the HCR-20 violence risk assessment scheme and the Psychopathy Checklist: Screening Version (PCL: SV) in the prediction of diversion non-compliance, and recidivism in a sample of 120 defendants, and (3) identified alternative factors that help defendants succeed in diversion through a multiple case-study design. Results revealed that this sample consisted primarily of minority male defendants with extensive histories of prior arrests, significant histories of physical abuse, homelessness and suicidality, and co-morbid substance abuse and psychiatric disorders. The findings provided preliminary validation of the predictive validity of the HCR-20 and PCL: SV with defendants diverted to community treatment. The HCR-20 was found to be superior to the PCL: SV in predicting both non-compliance and recidivism, and the PCL: SV proved to be more useful in predicting recidivism than non-compliance. Results of multiple case-studies found a pattern of characteristics shared by participants who failed diversion regardless of HCR-20 results. These variables included history of physical abuse, family history of substance abuse or criminal behavior, levels of social support, and level of responsibility taken for the instant offence.

  • El modernismo desde dentro: Discurso de la "gente nueva" y campo literario en la prensa modernista madrileña (1897-1907)

    Author:
    MARIA SUSANA BARDAVIO ESTEVAN
    Year of Dissertation:
    2010
    Program:
    Hispanic & Luso Brazilian Literatures & Languages
    Advisor:
    William Sherzer
    Abstract:

    This dissertation examines the trajectory of modernist discourse between 1897 and 1907 and its impact on the process toward autonomy of Madrid's literary field. In the late nineteenth century, the failure of the liberal project and of positivism plunged European thought into what has been called the fin de siècle crisis. Spain participated fully in this process, generating a series of protest discourses that rejected the prevailing system. In the arts and literature in particular, this led to a number of trends aesthetically or ideologically opposed to the political system of the Restoration, to bourgeois values, to radical positivism and to realist aesthetics. The material and social conditioning factors greatly hindered the development of the new aesthetics. This caused the young writers to come together as a community of discourse conjoining the plurality of perspectives that characterized them under two basic principles: the defense of literary renewal and the rejection of the established powers. The constant struggle for these two assumptions laid the foundations for a symbolic revolution in the literary field. I understand modernism as the collective discourse that in the late nineteenth century started to make its way into the literary field and whose impact on it would be crucial in the process of autonomization. My study focuses on the public sphere of modernist discourse. I have examined mainly the modernist magazines published in Madrid between 1897 and 1907 because, compared to the consecrated press, they were the means by which the gente nueva could freely express and disseminate their opinions. Throughout the dissertation I explore the development of modernist discourse to show that it was not immutable, but that it was changing within the literary field. As it was gaining recognition, the modernist writers adopted literary positions that caused confrontations among themselves, leading to the breakup of the original community of discourse. However, they were still sharing the defense of the aforementioned principles, and when they finally imposed them and their discourse was perceived as legitimate by the whole field, a degree of autonomy hitherto nonexistent in the literary world was eventually reached.

  • The Role of Sleep in Odor Memory Consolidation Within the Piriform Cortex

    Author:
    Dylan Barnes
    Year of Dissertation:
    2014
    Program:
    Psychology
    Advisor:
    Donald Wilson
    Abstract:

    Sleep is important for memory consolidation. One potential mechanism of memory consolidation is replay, where recently formed memories are repeated during post-learning sleep. For example, the firing sequences evoked in hippocampus during learning are spontaneously replayed during bouts of slow wave sleep (SWS). The phenomenon of replay during SWS is common in many neocortical systems. Odor memory may also rely on sleep-dependent consolidation, even though olfaction is not a neocortical system. The primary olfactory (piriform) cortex is a three-layered archicortex receiving direct input from the olfactory bulb. Piriform cortical activity during slow-wave sleep-like states is modified by recent odor experiences and becomes highly coherent with the amygdala and hippocampus, suggesting a possibility of replay in the olfactory system. The goal of this research was to describe the role post-training sleep had in odor memory consolidation. The initial study utilized two different types of conditioning: standard odor fear conditioning and differential fear conditioning to examine how olfactory training can affect perceptual odor discrimination. Results from this study showed that animals that undergo differential odor fear conditioning are better able to discriminate similar odors following conditioning compared to animals that undergo standard conditioning. Furthermore, this change in perception is possible through changes in the receptive fields of individual units within the piriform cortex. The next study examined how SWS in the anterior piriform cortex is involved in olfactory memory consolidation following odor fear conditioning. The amount of time animals spent in SWS following conditioning significantly increased compared to baseline habituation days and the amount of time animals spent in SWS following learning predicted how much time they froze to the odor during testing. Finally, the last study assessed changes in both the strength and precision of olfactory memory following modifications made during post-training SWS. Imposing replay of the learned odor during post-training SWS enhanced the strength of the odor memory, while imposing replay of another odor stimulus caused animals to generalize their fear response to multiple olfactory stimuli. Taken together, these results underlie the importance of sleep in the consolidation of both the strength and precision of odor memory.

  • Negotiating labyrinths of risk: The impact and implementation of a structured violence risk assessment instrument in juvenile parole

    Author:
    Kevin Barnes-Ceeney
    Year of Dissertation:
    2013
    Program:
    Criminal Justice
    Advisor:
    Jeff Mellow
    Abstract:

    ABSTRACT Negotiating labyrinths of risk: The impact and implementation of a structured violence risk assessment instrument in juvenile parole Kevin Barnes-Ceeney Risk assessment has become a critical aspect of correctional work. Risk assessment instruments are often used by criminal justice workers to predict the likelihood of prison escape, recidivism, or an offender's potential for perpetrating future harms. Increasingly, state parole boards are using risk assessment to assist in their evaluation of offenders' risks, to identify requisite interventions, and to ascertain suitability for parole. Although there has been considerable research concerning the predictive validity of risk factors, few studies have examined how criminal justice workers experience and understand risk assessment, and how such understandings impact decision making. Many scholars have posited that the use of risk assessment to inform discretion decisions can improve the consistency and accuracy of recidivism prediction. Others, however, suggest that risk assessment instruments are indicative of the pernicious scientification of administration, and that an emphasis on risk factors may lead workers to practice containment rather than resolution, ensnaring individuals in biographical "labyrinths of risk." Despite extensive risk theorization, few scholars have examined the impact of risk technologies at the individual and organizational level. This mixed methods case study addresses this gap in the literature. The qualitative inquiry answers the central research question: How do juvenile justice actors experience and understand risk assessment processes? Subsidiary questions seek to unpack these experiences and understandings by asking: How do juveniles experience labyrinths of risk? and What is the nature of risk labyrinths? The quantitative part of the study answer the question: Does the implementation of a structured risk assessment increase the number of juveniles released early on parole? Tracking the implementation of the Structured assessment of violence risk in youth (SAVRY) assessment tool, in juvenile parole in New Jersey, this dissertation seeks to understand the meanings juvenile justice actors ascribe to risk, and how such understandings shape juvenile justice system responses. Semi-structured interviews focusing on perceptions of risk were conducted with three juvenile parole board members, six parole hearing team officers, 12 Juvenile Justice Commission staff, and 10 committed juveniles. Where possible, interviews were recorded and transcribed. Forty-five parole board hearings were also observed, and 21 case files were selected and transcribed. Quantitative data comprised of 445 SAVRY assessed and un-assessed juvenile cases. Cases were matched on the following variables: age within 6 months of index offense, gender, sentence length, seriousness of index offense score, and the Offender Group Reconviction Scale 3 (OGRS 3.) A grounded theory approach was adopted to analyze the qualitative data. Line-by-line open coding of transcripts was conducted, using Atlas ti qualitative data analysis software. The constant comparison method was used to refine initial codes, and develop pattern codes. Repeated patterns of meaning were grouped into themes, and the themes discussed with study participants. The quantitative data was analyzed through a survival analysis. Hazard curves were generated to examine whether assessed juveniles are likely to be released earlier than non-assessed juveniles. The findings suggest that juveniles who received a SAVRY assessment were more likely to be released earlier on parole, after an initial period of one year had passed. Parole board members felt that the SAVRY instrument was helpful as they are required to chart a course through large amounts of risk information. Risk assessment instruments do not create labyrinths of risk, however the labyrinths of risk metaphor is still useful. Risk assessment instruments appear to serve as Ariadne's thread helping to guide parole board members as they negotiate labyrinths of risk when making a parole decision. Furthermore, a juvenile's progression through the juvenile justice system can be likened to a classical labyrinth, consisting of a single unicursal path leading to the center and out again. Successful navigation of such a labyrinthine structure involves a process of transformation, in which the juvenile is expected to extinguish his offending self, thereby metaphorically slaying the Minotaur. A net labyrinth awaits the juvenile on his release. Organizational interconnectivity is of critical importance when a juvenile negotiates such a postmodern labyrinth of labyrinths. This dissertation facilitates a better understanding of the interplay between risk assessment instruments and juvenile justice decision-making. The findings improve knowledge of the barriers to successful risk assessment implementation, and identify problems with intra-and inter-organizational connectivity. Training opportunities for juvenile justice actors are identified, which facilitate the adoption of effective risk management procedures. Key findings of the dissertation were disseminated to juvenile justice employees through face-to-face discussions during the data analysis process, and meetings with senior parole officials.

  • MINORITIES' PERCEPTIONS OF MINORITY-WHITE BIRACIALS: THE ROLE OF IDENTIFICATION FOR COGNITIVE, AFFECTIVE, AND BEHAVIORAL RESPONSES

    Author:
    Sabrica Barnett
    Year of Dissertation:
    2014
    Program:
    Psychology
    Advisor:
    Daryl Wout
    Abstract:

    Research on intergroup relations has a rich history in social psychology, with scholars devoting a considerable effort investigating factors that influence stereotyping, prejudice and discriminatory behavior. The results of these studies suggest that individuals' cognitions, affect, and behaviors are affected by their own group memberships as well as the groups to which others belong. People generally view the groups that they belong to (their ingroup) positively, and view the groups that others belong to (outgroups) stereotypically (Tajfel & Turner, 1986). However, much of the research on social identification and subsequent perceptions has focused on socially distinct groups rather than groups that blur categorical boundaries. As such, there is a dearth of research on how individuals identify with and perceive people who belong to multiple racial groups. To address this gap in the literature, I investigated minorities' identification with minority-White biracials, as well as the downstream cognitive (warmth and competence stereotypes), affective (pride, shame), and behavioral (facilitation, distancing) consequences of identification across three studies. Results demonstrated that Black (Study 1) and Hispanic (Study 2) participants were equally identified with biracials and other ingroup members (Blacks, Hispanics), and were less identified with outgroup members (Whites). In contrast, White participants (Study 1) were most identified with other White people, least identified with Black people, and moderately identified with Black-White biracial people. Moreover, Black participants stereotyped Blacks and Black-White biracials as equally warm and competent (Study 1); Hispanic participants felt equally proud of and were equally willing to help Hispanics and Hispanic-White biracials (Study 2); and both Black and Hispanic participants felt equally ashamed when a Black or Hispanic and Black-White or Hispanic-White biracial person acted in a stereotypically negative manner, and wanted to distance themselves from the wrongdoer (Study 3). In contrast, minorities perceived Whites less positively across measures of stereotypes, emotions and behaviors. Finally, consistent with self-categorization theory (Turner et al., 1987), minorities' identification with minority-White biracials predicted their group-based stereotypes, emotions and behaviors. These results make an important contribution to the limited work on perceptions of biracial people, and extend previous research regarding the role of identification for intergroup perceptions.

  • Counterfeiting in American Literature

    Author:
    Todd Barosky
    Year of Dissertation:
    2010
    Program:
    English
    Advisor:
    David Reynolds
    Abstract:

    This dissertation provides an analysis of representations of counterfeiting in American literature across the eighteenth and nineteenth centuries. One of the oldest crimes in America and until the Civil War one of the most prevalent, counterfeiting appealed to the literary imagination not merely because it was so common, but because, as a fundamentally ambiguous activity, it seemed to expose significant fault lines in American life. The ambiguity of counterfeiting arose from the fact that its performance, and especially its successful performance, explicitly challenged the stability of the concepts, such as monetary value and sovereign authority, that were necessary to define it as a crime. Counterfeiting thus probed the shifting and often permeable boundaries between what was considered legitimate and illegitimate, legal and illegal, moral and immoral, natural and artificial, valuable and valueless, real and imaginary. The subject of counterfeiting became for a diverse group of American writers, from Benjamin Franklin, Stephen Burroughs and Charles Brockden Brown in the eighteenth century, to John Neal, George Lippard, and Herman Melville in the nineteenth century, a lens through which social and political analysis could be brought into focus, and a fertile source of philosophical speculation and literary creation. Once it was figured as a literary subject, counterfeiting also had a profound impact on the texture and development of American literature across this period. Most obviously, attempts to represent counterfeiting and counterfeiters gave rise to new experiences, new characters, new settings, and new vernaculars. Less obviously, the ambiguity of counterfeiting was such that it exerted pressure on the traditional literary forms, such as the picaresque narrative and the gothic novel, which were deployed in an effort to make it meaningful. What is more, sustained reflection upon the meaning of counterfeiting often led American writers to doubt the possibility of truthful or meaningful representation as such. "Counterfeiting in American Literature" thus seeks to demonstrate that the subject of counterfeiting exists in American literature as a site of literary creativity and cultural tension, a site where older literary forms are recast to fit new circumstances, and where different ideas are inaugurated and tested.

  • Boronic Acids as Penicillinase Inhibitors

    Author:
    Juan Barquero
    Year of Dissertation:
    2013
    Program:
    Biochemistry
    Advisor:
    Manfred Philipp
    Abstract:

    Abstract Boronic Acids as Penicillinase Inhibitors by Juan F. Barquero Advisor: Dr. Manfred Philipp. £]-lactamases are enzymes produced by bacteria resistant to antibiotics. A common feature on beta lactam antibiotics is the beta-lactam ring. £]-lactamases hydrolyze the £]-lactam ring leaving the antibiotic inoperative. The advent of bacteria that are resistant to £]-lactams has impelled researchers to find inhibitors for £]-lactamases that mimic the lactam ring but do not get hydrolyzed. One group of these new antibiotics is the aryl boronic acids. The main reason the boronic acids have been chosen as potential drugs is their lack of toxicity and their easy excretion in the urine. One of the most important structural features of these compounds is their chemical and geometric fitness in the active site of £]-lactamases. Boronic acids mimic the tetrahedral intermediate formed in the half-acylation reaction that occurs during the hydrolysis of the fÒ-lactam ring. The major goal of the research presented here was to discover new aryl boronic acids inhibitors of penicillinases from the class A £]-lactamases. To accomplish this goal, commercially available boronic acids that are manufactured for the Suzuki reaction were used. These compounds included fluorinated, chlorinated, brominated, carboxylated, nitrophenylated, pinacol-esterified and thiophene-carboxylated aryl boronic acid derivatives. Kinetic evaluations of each class of compounds were performed under pseudo first-order enzymatic reaction conditions and the inhibitory constants (Ki) were reported using nitrocefin as substrate for two enzymes: the in-house expressed £]-lactamase BlaC and the £]-lactamase from Bacillus cereus 569/H9 (Calbiochem) identified as TEM-116. The structure-activity relationship (SAR) showed that the most potent inhibitors of BlaC £]-lactamase were 2-carboxythiophene-5-boronic acid; 3,4,5-trifluorophenylboronic acid; 3-nitrophenytlboronic acid and 2,3,4,5-tetrafluorophenylboronic acid, Ki values of 1.2, 175.7, 213.9 and 228.6 micromolar respectively. In addition, SAR revealed that the most potent inhibitors for Bacillus cereus £]-lactamase I were 2-carboxythiophen-5-boronic acid, 3-carboxyphenylboronic acid, 2-carboxythiophene-4-boronic acid, and 3-carboxy-4-fluorophenylboronic acid having Ki values of 1.1, 19.4, 46.5, and 47.1 micromolar respectively. To gain further insight into the molecular interactions between each class of inhibitors and their targeted enzymes docking experiments were performed using Autodock Vina program combined with Sculpt from MDL and followed by the molecular visualization of the protein-ligand complexes using Swiss-PdbViewer and DiscoveryStudio from Accelerys. The results conclusively show that some selective classes of aryl boronic acids are potent competitive inhibitors of BlaC and Bacillus cereus £]-lactamase I and that they should be further considered for advanced drug discovery and improvement of treatment against antibiotic resistant bacteria. Furthermore, the discovery that 4,4¡¦-DDT is an inhibitor of Mycobacterium tuberculosis £]-lactamase, combined with in silico studies, suggests that further elaboration of this molecule may be one route to new inhibitors.

  • Contact-induced changes in word order and intonation in the Spanish of New York City bilinguals

    Author:
    Carolina Barrera-Tobon
    Year of Dissertation:
    2013
    Program:
    Hispanic & Luso Brazilian Literatures & Languages
    Advisor:
    Ricardo Otheguy
    Abstract:

    This dissertation is a variationist sociolinguistic analysis of the variable word order and prosody of copular constructions (Nicolás es feliz versus Feliz es Nicolás, Es Nicolás feliz, Es feliz Nicolás, `Nicolas is happy') in the Spanish of first- and second-generation Spanish-English bilinguals in New York City. The data used for the study come from a spoken corpus of Spanish in New York City based on 140 sociolinguistic interviews (details of the corpus will be presented in Chapter Three). This dissertation addresses the question of whether second-generation bilinguals have a less flexible word order in Spanish as a result of their increased use of, and contact with, English, where a more fixed order prevails. We will show that the informants in the present study, like their peers in Los Angeles and other parts of the US, exhibit a more rigid word order compared to their first-generation peers. We have established that this increase in rigidity of word order among the second-generation can be attributed in large part to their increased use of and contact with English. The studies mentioned above have interpreted their results to mean that these speakers are losing or have lost the discourse pragmatic constraints that govern word order. However, the data here show that the first- and second-generation speakers in the present study share many of the same conditioning variables and constraints for word order, although these variables appear to account for a smaller amount of variance among the second-generation. In this way, we have established that the second-generation is not losing the discourse pragmatic constraints that govern word order, but that they are differently sensitive to these constraints. In fact, we show that second-generation speakers are very capable of communicating the pragmatic functions that the first-generation speakers do using word order because they maintain the prosodic details of their first-generation counterparts. In other words, the second-generation communicates these functions in ways that are slightly different from the first-generation, relying more on prosodic resources than syntactic ones. Furthermore, the data indicate that their prosodic patterns are not modeled after the prosody of English. In general terms we show that the second-generation does not have a different grammar from their first-generation counterparts, as is claimed by other researchers. Instead we show that these speakers favor certain first-generation strategies over others.