The Transverse-Field Ising Spin Glass Model on the Bethe Lattice with an Application to Adiabatic Quantum Computing

In this Ph.D. thesis we examine the Adiabatic Quantum Algorithm from the point of view of statistical and condensed matter physics. We do this by studying the transverse-field Ising spin glass model defined on the Bethe lattice, which is of independent interest to both the physics community and the quantum computation community. Using quantum Monte Carlo methods, we perform an extensive study of the the ground-state properties of the model, including the R\'enyi entanglement entropy, quantum Fisher information, Edwards--Anderson parameter, correlation functions. Through the finite-size scaling of these quantities we find multiple independent and coinciding estimates for the critical point of the glassy phase transition at zero temperature, which completes the phase diagram of the model as was previously known in the literature. We find volumetric bipartite and finite multipartite entanglement for all values of the transverse field considered, both in the paramagnetic and in the glassy phase, and at criticality. We discuss their implication with respect to quantum computing. By writing a perturbative expansion in the large transverse field regime we develop a mean-field quasiparticle theory that explains the numerical data. The emerging picture is that of degenerate bands of localized quasiparticle excitations on top of a vacuum. The perturbative energy corrections to these bands are given by pair creation/annihilation and hopping processes of the quasiparticles on the Bethe lattice. The transition to the glassy phase is explained as a crossing of the energy level of the vacuum with one of the bands, so that creation of quasiparticles becomes energetically favoured. We also study the localization properties of the model by employing the forward scattering approximation of the locator expansion, which we compute using a numerical transfer matrix technique. We obtain a lower bound for the mobility edge of the system. We find a localized region inside of the glassy phase and we discuss the consequences of its presence for the Adiabatic Quantum Algorithm

Characterization of Trailing Line Vortices

Mean velocity surveys were taken for axial or trailing line vortices produced behind a bi-wing vortex generator in a low-speed wind tunnel. Data were taken primarily with a seven-hole probe at a speed of 30m/s; but vortex steadiness was studied using smoke flow visualization over a speed range between 10 and 40 m/s. Various generator center body configurations were studied, with particular interest directed toward how a centerline jet and an asymmetric, unsteady circumferential flow influenced the mean velocity profiles. This study found that a centerline jet did not produce a well-behaved two-cell vortex over the parametric range available in the wind tunnel. Mean velocity profiles that were produced when circumferential disturbances were introduced via the center body were found to be identical, within experimental error, to mean profiles produced behind the same configuration with the injection slots taped. Since vortex stability, with respect to vortex breakdown, has been delineated using Rossby number, steady vortex velocity profiles have been identified in terms of local Rossby and Reynolds number. Using an axial-based Reynolds number, these experiments covered a Reynolds number range of 8,900 to 21,400 and the Rossby number varied between 0.99 and 2.20

RECLAIMING OUR HUMANITY: REDEMPTION, REIMAGINING, AND RESTORYING OF THE FOUNDATIONS FOR SUCCESS OF FORMERLY INCARCERATED AFRICAN AMERICAN MALES

Reclaiming Our Humanity: Redemption, Reimagining, and Restorying of the Foundations for Success of Formerly Incarcerated African American Males African American men represent the highest population found in the criminal justice system. Systemic racism contributes to the high recidivism rates of formerly incarcerated Black men. Additional barriers to affordable education, job training, and other services exist for the formerly incarcerated. The purpose of this study was to interview formerly incarcerated African American men and provide a counter-narrative of the foundations for success post-incarceration. This research project explored the narratives of the lived experiences of formerly incarcerated Black men through the lenses of two theoretical frameworks: Black critical race theory and abolitionist theory. Together these frameworks work to shift the narrative around decarcerated Black men. Data were collected via one-on-one interviews with six formerly incarcerated African American men based in California. Six themes emerged from the data: (1) Early educational experiences: The love for learning that was not cultivated; (2) The absence of belonging: Growing up in a traumatic environment incarceration; (3) Incarceration: Building meaningful connections through mentorship, reading, and debating; (4) Post-incarceration: Programs facilitating transition and educational opportunities; (5) Factors that build success: Reactivating the genius inside us, networking, and education; and 6) Recommendations and the foundations for success. The findings of this study highlight the additional barriers that formerly incarcerated African American males encounter during reentry and job placement. Furthermore, the results highlight iii the urgency of providing culturally relevant mentorship and affordable education, job training, job placement and cross-collaboration between institutes of higher learning and reentry organizations, along with developing increased awareness and understanding of the unique needs of formerly incarcerated African American males. Results from this study offer insight and implications for improving the reentry experiences of African American males in both policy and practice

Thin-Layer Prestressed Composite Ferroelectric Driver and Sensor Characterization with Application to Separation Flow Control

Experiments were conducted in two different stages--general piezoelectric actuator characterization and flow separation control applications. The characterization of the piezoelectric devices was performed in several stages, due to the many variables that affect performance. The first stage of the characterization consisted of tests conducted on 13 different THUNDERTM (thin-layer composite unimorph ferroelectric driver and sensor) configurations. These configurations consisted of a combination of 1, 3, 5, 7, and 9 layers of 25μ thick aluminum as backing material, with and without a top layer of 25μ aluminum. All of these configurations used the same piezoelectric ceramic wafer (PZT-5A) with dimensions of 5.1 x 3.8 x 0.018 cm. The above configurations were tested at two stages of the manufacturing process: before and after re-poling. The parameters measured included frequency, driving voltage, displacement, capacitance, and radius of curvature. An optical sensor recorded the displacement at a fixed voltage (100-400 Vpp) over a predetermined frequency range (1-1000 Hz). These displacement measurements were performed using a computer that controlled the process of activating and measuring the displacement of the device. A parameter was defined which can be used to predict which configuration will produce maximum displacement for a partially constrained device. The second phase of the characterization was conducted using two different types of piezoelectric devices. Actuators were made with PZT wafers of 3.8 x 1.9 x 0.025cm, and 3.8 x 1.3 x 0.02 cm. These models consisted of a combination of top layers of 1 mil (0.0254 mm) aluminum and brass, and bottom layers of stainless steel, aluminum, and brass of varying thickness (3, 4, 5, 7, 9, 10 mil (0.076, 0.102, 0.127, 0.178, 0.229, 0.254 mm)). Displacement was measured for 12 configurations at 1 Hz and 200 Vpp under loads of 0, 0.2, 0.4, 0.5, and 1.0 Kg using an optical sensor. Again the parameter β was used to predict the configuration with the maximum displacement for a partially constrained device, as well as with the device under load. Finally, a THUNDERTM based actuator was used to deploy submerged vane-type vortex generators which were used to control turbulent separated flow associated with flow over a backward-facing ramp. Effectiveness of the vortex generator array was demonstrated using wall pressure measurements, velocity surveys, and smoke-oil flow visualization photographs which showed that the nominal flow separation region was reduced by 35-40%

Problem gambling among older people. An italian study on habits, representations, levels of engagement and psychosocial determinants

Gambling participation among older people has grown over the years. Elders constitute a large and fast-growing population in Italy, but little empirical evidence describes gambling patterns among older Italian adults and the problem gambling (PG)’s psychosocial determinants, so a range of questions which are crucial to orient prevention strategies remain unanswered. The present study aims to investigate habits, representations, levels of engagement in gambling among Italian elders and the role of loneliness, social support and well-being in explaining their problem with gambling. A convenience sample of 165 participants (mean age: 66.93; SD = 5.73; women: 43.1%) was involved. Gambling activities, habits, representations and PG rates were examined. A group “at moderate risk/problem gambling” (scoring >7 on PGSI, n = 40) and a control group (scoring 0 on PGSI, n = 40) were selected from the whole sample, balanced on socio-demographic characteristics; a one-way analysis of variance (ANOVA) was used to compare the two groups on the target psychosocial variables. 11.5% of the sample was found to meet the PGSI criteria for PG; 26.7% for moderate risk; 11.5% for problem gambling; 50.3% were classified as no-problem gamblers. Scratch cards were the main form of gambling among all groups; the chance to make more money and to distract oneself from other problems were the main reasons to gamble. Finally, the group “at moderate risk/problem gambling,” compared to the control group, expressed higher loneliness, as well as lower perceived social support and well-being

Attachment relationships and internalization and externalization problems in a group of adolescents with pathological gambling disorder

Objective: The evidence accumulated in the relevant literature suggests that the presence and evolution of gambling could be correlated with the internalizing and externalizing problems and with the attachment style. This paper aims at exploring this perspective further. In particular, it analyses how such risk factors interact within the specific context of adolescent gambling disorder. Method: The sample comprises 91 adolescents, 61 male and 30 female, in the 17-22 age range (M = 17.77; SD = 0.98). A structural equation model was used to examine the relationship between the Youth Self-Report latent factors and pathological gambling, and the mode of attachment was assumed to act as a moderator. Results: Our results suggest that in the group characterized by a fearful attachment style there was a positive relationship between somatization and propensity to risk (p = 0.008), whereas in the dismissing attachment group there was a positive relationship between a greater tendency to delinquent behaviour and gambling risk (p = 0.042). Conclusions: The various insecure attachment stylespatterns may contribute in different ways to the development of oppositional-provocative behaviour and problems of conduct in adolescents

Evaluation of performance at university with the Rasch Analysis

In 2007/2008 the University of Salento has started a degree course in Psychology. Right from the start, the people in charge of the course have been focusing on preventing early dropouts by stimulating a better professional awareness and by ensuring the best possible course experience. To do so, the students were asked increasing performance standards to prevent the choice of university studies as mere alternative to work. This study refers specifically of controlling the training process through the analysis of perfor- mance of students (monitoring career). Normally a review of developments in the curriculum in relation to explanatory variables is performed using sta- tistical inferential model where the dependent variable is the grade obtained in the different disciplines or even the credits acquired by the student. The particular structure of the activity since its inception allows to introduce the evaluation of the curriculum using effectively Rasch Analysis. The model involves the insertion of the exams outcomes analysed in terms of success / failure examination for each of the constituent disciplines of studies. This model establishes a more reliable criteria for the verification of differential variables useful for monitoring the training process (for example: final grade to high school diploma, sex, age, university registration renewal , etc.) and the subsequent management of the training process