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Yes / Highly oriented long-chain-branched poly (lactic acid) (LCB-PLA) was prepared and the structure evolution was studied in the process of solid die drawing by compared with poly (lactic acid) (PLA). During drawing, samples underwent not only die drawing process but also free drawing process. Drawing speed presented a prominent effect on the free drawing process, while die thickness showed a more obvious influence on the die drawing process. For PLA, free drawing process mainly contributed to its final orientation degree and crystallinity, and thus the mechanical properties of PLA were greatly influenced by drawing speed. However, for LCB-PLA, die drawing process made a greater contribution to the final orientation degree and crystallinity, and its mechanical properties were mainly affected by die thickness. Under the same drawing condition, the tensile strength and modulus of LCB-PLA were always higher than those of PLA, and reached up to 228 MPa and 7.2 GPa, respectively, which basically met the requirement for born fixation materials. Samples which only underwent die drawing showed obvious “sandwich” structure, and the thickness of the oriented skin layer for LCB-PLA was thicker than that for PLA, suggesting that shear-induced orientation can be easily retained due to the enhanced entanglement between long branched chains. After drawing, LCB-PLA samples showed smaller lamellae size (Llateral) but larger long period (Lac) compared with PLA, suggesting that the low chain mobility restricted the motion of chain slipping of LCB-PLA and thus resulted in the fragmentation of neighboring crystal lamella by chain stretched-out.

Left ventricular flows in the human heart are very complex and in the presence of a diseased condition, such as unhealthy or prosthetic heart valves, the complexity of the flow is further increased. The intricacy of the heart geometry combined with the pulsatile character of the flow, the interaction of high-speed jets with the flexible walls, and the unsteady motion of the heart valve leaflets generate inherently complicated flow fields. It is therefore essential that we study and understand the complex cardiac energetics and physics of blood flow in both healthy and diseased hearts. Although artificial heart valves, mechanical and biological, have evolved to a level of universal acceptance, they have never reached a level of performance comparable to that of the natural valves of the heart. Many of the problems are directly related to the fluid mechanics. Considering that mechanical heart valves (MHV) are more commonly implanted because of their durability, it is imperative to better understand their hemodynamic behavior. Yet to date, no study has documented in depth the complex hemodynamic characteristics of left ventricular flows and assessed the intricate structures that are generated in the left ventricle (LV) due to vortex formation (roll-up of shear layers shed past the valve leaflets), turbulence characteristics, and energetics. The flow through pivoted leaflets of MHVs induces a combination of flow characteristics that are dependent on the specific valve design and orientation. The aim of the present study is to provide new insight into the spatio-temporal dynamics of the flow distal to a mitral MHV by employing a state-of-the-art, high resolution, flow diagnostic method, Time Resolved Digital Particle Image Velocimetry (TRDPIV) in a flexible, transparent LV documenting the evolution of eddies and turbulence during a complete period of the heart cycle. The broad impact of the proposed research extends beyond the hemodynamics of heart valve prosthesis. The research herein will enable the development of a tool for application in all cardiac energetic studies (unhealthy valves, tissue engineered valves, cardiac remodeling stages, and even congestive heart failure) and aid in better diagnosis of the efficiency and performance of the heart. The last component of the dissertation involved the translation of my dissertation research into an engineering educational tool for undergraduate engineering students. / Ph. D.

Married bisexuals who come out to their heterosexual partners do not invariably divorce. This qualitative study included 14 intact, mixed orientation married couples. The mean marriage duration was 14.5 years, and the mean time since the bisexual spouse had come out was 7.9 years. The research focused the negotiation processes around three constructs: (a) sexual identity; (b) gender identity; and (c) marital commitment. Dyadic interviews were used to generate a grounded theory of the identity and commitment negotiation processes occurring among intact mixed orientation married couples. The findings revealed two sexual identity trajectories: Bisexuals who identify before marriage and reemerge within marriage; or bisexuals who do not identity before marriage but who emerge from within marriage. Two gender identity processes were reported: gender non-conformity and deliberate gender conformity. Finally, two negotiation processes around marital commitment were found: (a) closed marital commitment, and (b) open marital commitment. Closed marital commitment was defined as monogamous. Open marital commitment had four subtypes: (a) monogamous with the option to open; (b) open on one side (i.e., the bisexual spouse was or had the option to establish a tertiary relationship outside the marriage); (c) open on both sides or polyamorous; and (d) third-person inclusive (i.e.. couples had or were seeking a third person to bring into their marriage for both spouses). The implications for research and clinical practice were discussed. / Ph. D.

The American Counseling Association recently adopted standards of competency for counselors working with lesbian, gay, and bisexual (LGB) clients (Logan & Barret, 2005). Concurrently, the Council for Accreditation of Counseling and Related Educational Programs (CACREP) revised standards to require social and cultural diversity competencies, including LGB counseling competency, to be interwoven throughout counselor education curriculum (CACREP, 2009). Yet the ways that counselor educators are including these initiatives are unknown. Additionally, the factors that improve counselor competency with LGB clients are also unknown. Therefore, the purpose of the study was to examine counselors' self-perceived competency when counseling lesbian, gay, and bisexual clients and identify variables that are related to and predictive of LGB counseling competence. The quantitative study included 479 members of a southeastern state's professional counseling association including school counselors, community-based counselors, counselor educators, and counseling students. The assessment included an Information Questionnaire to collect data regarding personal and professional background, a Religiosity Index (Lippman et al., 2005; Statistics Canada, 2006), Spiritual Transcendence Index – Modified (adapted from Seidlitz et al., 2002), the Marlowe-Crowne Social Desirability Scale - Short Form C (Reynolds, 1982), and the Sexual Orientation Counselor Competency Scale (Bidell, 2005). Among results, counselors felt least competent in their skills with LGB clients, compared to knowledge and attitudes subscales. An ANOVA revealed that counselor educators perceived themselves as significantly more LGB-competent than counselors in other practice settings did. School counselors also reported significantly lower levels of LGB counseling competence than community counselors. Multiple regression analysis revealed that religiosity inversely predicted LGB competence whereas spirituality had a positive predictive relationship with LGB competence. Finally, there was a marked deficit in training experiences involving LGB issues for counselors in the sample. Implications of the findings suggest a need to increase experiential components of counselor training to strengthen counselors' skills with LGB clients, as well as improve the self-efficacy of school counselors in their work with LGB students. A unique finding to the study involved counselor spirituality as a positive predictor of LGB competence, perhaps indicating higher levels of compassion and connectedness to others despite differences; future studies should investigate this relationship further. / Ph. D.

For over a century, the enigmatic nature of narcissism has been the source of debate across psychological, sociological, and developmental domains. Although much has been written in recent years about narcissism as a generational phenomenon, referencing data collected from university undergraduates, there is little to no applied research and discussion into the implications for teaching and learning with respect to the reciprocal interactions between narcissistic students and traditional undergraduate education. Recognizing this paucity in the literature, the manuscripts within this dissertation draw theoretical and empirical connections between narcissism and learning, highlighting significant relationships between narcissism as a dispositional construct and achievement goal orientation. Through the development of a theoretical Triarchic Model of Dispositional Narcissism and the empirical exploration of its viability, this dissertation is written in accordance with sentiments that suggest educational psychologists seek to improve learning through a more comprehensive recognition of the variables that contribute to cognitive processes. The theoretical design, research, and interpretations within this dissertation seek to provide a heuristic through which educators may develop proactive, interventive instructional models and pedagogies that will encourage all students to improve their learning by engaging in strategies that lead to deeper cognitive and metacognitive processing. / Ph. D.