Attachment priming and avoidant personality features as predictors of social-evaluation biases

Personality research has shown that negativity in social situations (e.g., negative evaluations of others) can be reduced by the activation of participants' sense of attachment security. Individuals with avoidant personality disorder (APD), however, are theoretically less responsive to context or situational cues because of the inflexible nature of their personality disposition. This idea of individual differences in context-responsiveness was tested in a sample of 169 undergraduates who were assessed for APD features and assigned to positive, negative, or neutral attachment priming conditions. More pronounced APD features were associated with more negative responses to vignettes describing potentially distressing social situations. A significant interaction showed that participants with more avoidant features consistently appraised the vignettes relatively more negatively, regardless of priming condition. Those without APD features, by contrast, did not exhibit negative appraisals/evaluations unless negatively primed (curvilinear effect). This effect could not be explained by depression, current mood, or attachment insecurity, all of which related to negative evaluative biases, but none of which related to situation inflexibility. These findings provide empirical support for the notion that negative information-processing is unusually inflexible and context-unresponsive among individuals with more pronounced features of APD

Study of air pollutant detectors

The application of field ionization mass spectrometry (FIMS) to the detection of air pollutants was investigated. Current methods are reviewed for measuring contaminants of fixed gases, sulfur compounds, nitrogen oxides, hydrocarbons, and particulates. Two enriching devices: the dimethyl silicone rubber membrane separator, and the selective adsorber of polyethylene foam were studied along with FIMS. It is concluded that the membrane enricher system is not a suitable method for removing air pollutants. However, the FIMS shows promise as a useable system for air pollution detection

Pitch ability as an aptitude for tone learning

Tone languages such as Mandarin use voice pitch to signal lexical contrasts, presenting a challenge for second/foreign language (L2) learners whose native languages do not use pitch in this manner. The present study examined components of an aptitude for mastering L2 lexical tone. Native English speakers with no previous tone language experience completed a Mandarin word learning task, as well as tests of pitch ability, musicality, L2 aptitude, and general cognitive ability. Pitch ability measures improved predictions of learning performance beyond musicality, L2 aptitude, and general cognitive ability and also predicted transfer of learning to new talkers. In sum, although certain nontonal measures help predict successful tone learning, the central components of tonal aptitude are pitch-specific perceptual measures

Innovative concepts for aerodynamic control of wind turbine rotors

New systems for the aerodynamic control of wind turbine rotors are being studied in various projects funded by the UK Department of Energy. Results from a current project, ongoing at the National Wind Turbine Test Centre (NWTC) in Scotland are presented. These systems show the promise of much cheaper and more affective active control of horizontal axis wind turbines than has been achieved with full span and partial span pitching systems

Contributions of Signal-detection Mechanisms and Semantic Memory Representations to Famous Name Recognition

In past research, investigators have often used the recognition memory paradigm to study the cognitive and neural processes that permit the ability to accurately assess whether or not stimuli are familiar. This paradigm involves presenting stimuli to participants in a study phase, and examining their later recognition of them when these stimuli are subsequently presented again in a later test phase. It is not well understood, however, whether the same mechanisms that support familiarity assessment in recognition memory also support familiarity based on general life experience (e.g., recognizing a famous celebrity in daily life). To address this, I implemented modified recognition memory paradigms for the purpose of better understanding the processes that support famous name recognition. In Chapter 2, I developed a signal-detection model that describes how people discriminate between famous and fictional names. I found that similarly to recognition memory, famous name recognition relies on graded evidence that can be modeled successfully with Gaussian distributions. In Chapter 3, I studied the contributions of semantic knowledge to famous name familiarity, with a focus on recognition experiences in which ‘names ring a bell’. I revealed that despite the fact that participants understand this recognition experience to reflect situations where names are familiar but do not provoke retrieval of any related semantic details, they still achieve above-chance performance on an occupation forced-choice task for the same names. Based on these results, I investigated in Chapter 4 whether ‘name rings a bell’ experiences engage the same brain regions as those that also support the ability to successfully retrieve semantic knowledge about famous names. Using functional magnetic resonance imaging, I examined whether the brain regions that support ‘name rings a bell’ experiences overlap with those that support successful identification and correct occupation forced-choice decisions. Two brain areas that I found to be engaged during ‘name rings a bell’ responses were also engaged while participant’s successfully retrieved semantic knowledge for names, which included the left posterior middle temporal gyrus and an inferior aspect of the left ventrolateral prefrontal cortex. Overall, my thesis advances our knowledge of how feelings of familiarity for famous names relate to underlying semantic representations about them

Naturally Degenerate Neutrinos

The solar neutrino problem, atmospheric neutrino problem, and the existence of hot dark matter can all be economically accounted for using only the three known neutrinos if these neutrinos all have nearly degenerate masses of a few eV. We show how to generate this pattern of neutrino masses in a natural way within a `see-saw' framework.Comment: 10 pages, plain TeX, McGill-94/07, NEIP-94-003 (This is the version which is to appear in the journal. We have cleaned up typos, added references, and slightly expanded our treatment of radiative corrections.

Wave combustors for trans-atmospheric vehicles

The Wave Combustor is an airbreathing hypersonic propulsion system which utilizes shock and detonation waves to enhance fuel-air mixing and combustion in supersonic flow. In this concept, an oblique shock wave in the combustor can act as a flameholder by increasing the pressure and temperature of the air-fuel mixture and thereby decreasing the ignition delay. If the oblique shock is sufficiently strong, then the combustion front and the shock wave can couple into a detonation wave. In this case, combustion occurs almost instantaneously in a thin zone behind the wave front. The result is a shorter, lighter engine compared to the scramjet. This engine, which is called the Oblique Detonation Wave Engine (ODWE), can then be utilized to provide a smaller, lighter vehicle or to provide a higher payload capability for a given vehicle weight. An analysis of the performance of a conceptual trans-atmospheric vehicle powered by an ODWE is given here

Heterogeneous condensation of the Lennard-Jones vapor onto a nanoscale seed particle

The heterogeneous condensation of a Lennard-Jones vapor onto a nanoscale seed particle is studied using molecular dynamics simulations. Measuring the nucleation rate and the height of the free energy barrier using the mean first passage time method shows that the presence of a weakly interacting seed has little effect on the work of forming very small cluster embryos but accelerates the rate by lowering the barrier for larger clusters. We suggest that this results from a competition between the energetic and entropic features of cluster formation in the bulk and at the heterogeneity. As the interaction is increased, the free energy of formation is reduced for all cluster sizes. We also develop a simple phenomenological model of film formation on a small seed that captures the general features of the nucleation process for small heterogeneities. A comparison of our simulation results with the model shows that heterogeneous classical nucleation theory provides a good estimate of the critical size of the film but significantly over-estimates the size of the barrier.Comment: 9 pages, 10 figures, In Print J. Chem. Phy

Crystal Nucleation in a Supercooled Liquid with Glassy Dynamics

In simulations of supercooled, high-density liquid silica we study a range of temperature T in which we find both crystal nucleation, as well as the characteristic dynamics of a glass forming liquid, including a breakdown of the Stokes-Einstein relation. We find that the liquid cannot be observed below a homogeneous nucleation limit (HNL) at which the liquid crystallizes faster than it can equilibrate. We show that the HNL would occur at lower T, and perhaps not at all, if the Stokes-Einstein relation were obeyed, and hence that glassy dynamics plays a central role in setting a crystallization limit on the liquid state in this case. We also explore the relation of the HNL to the Kauzmann temperature, and test for spinodal-like effects near the HNL.Comment: 4 pages, 4 figure

The Index Of Narrative Microstructure: A Clinical Tool For Analyzing School-Age Children's Narrative Performances

Purpose: This research was conducted to develop a clinical tool-the Index of Narrative Microstructure (INMIS)-that would parsimoniously account for important microstructural aspects of narrative production for school-age children. The study provides field test age- and grade-based INMIS values to aid clinicians in making normative judgments about microstructural aspects of pupils' narrative performance. Method: Narrative samples using a single-picture elicitation context were collected from 250 children age 5-12 years and then transcribed and segmented into T-units. A T-unit consists of a single main clause and any dependent constituents. The narrative transcripts were then coded and analyzed to document a comprehensive set of microstructural indices. Results: Factor analysis indicated that narrative microstructure consisted of 2 moderately related factors. The Productivity factor primarily comprised measures of word output, lexical diversity, and T-unit output. The Complexity factor comprised measures of syntactic organization, with mean length of T-units in words and proportion of complex T-units loading most strongly. Principal components analysis was used to provide a linear combination of 8 variables to approximate the 2 factors. Formulas for calculating a student's performance on the 2 factors using 8 narrative measures are provided. Conclusions: This study provided a method for professionals to calculate INMIS scores for narrative Productivity and Complexity for comparison against field test data for age (5- to 12-year-old) or grade (kindergarten to Grade 6) groupings. INMIS scores complement other tools in evaluating a child's narrative performance specifically and language abilities more generally.Communication Sciences and Disorder