Scandate cathodes, where scandia is added to the tungsten cathode pellets, have recently received substantial and renewed research interest owing to significantly improved electron emission capabilities at lower temperatures, as compared with conventional dispenser cathodes. However, there are several persistent issues including non-uniform electron emission, lack of understanding regarding scandium’s role in the emission mechanism, and unreliable reproducibility in terms of scandate cathode fabrication. As a result, scandate cathodes have not yet been widely implemented in actual vacuum electron devices (VEDs). The surface structure and chemical composition of multiple scandate cathodes – prepared with the powder using the liquid-solid (L-S) technique – and exhibiting excellent emission behavior were characterized to give insight into the fundamental mechanism(s) of operation. This was achieved with high-resolution electron microscopy techniques that include high-precision specimen lift-out. These studies showed that the micron-sized tungsten particles that compose the largest fraction of the cathode body are highly faceted and decorated with nanoscale Ba/BaO (~10 nm), as well as larger (~150 nm) Sc2O3 and BaAl2O4 particles. The experimentally identified facets were confirmed through Wulff analysis of the tungsten crystal shape and were determined to consist of {110}, {100}, and {112} facets, in increasing order of surface area prevalence. Furthermore, it is estimated that Ba atoms decorating the tungsten crystal surfaces are present in quantities such that monolayer coverage is possible at elevated temperatures. The high-resolution electron microscopy techniques used to investigate the cross section (near-surface) of the L-S scandate cathodes also revealed that the BaAl2O4 particles (100-500 nm) that attach to the larger tungsten particles are either adjacent to the smaller Sc2O3 nanoparticles or encompass them. Furthermore, high-resolution chemical analysis and 3D elemental tomography show that the two oxides always appear to be physically distinct from each other, despite their close proximity. 3D elemental tomography also showed that the Sc2O3 particles can sometimes appear inside the larger tungsten particles, but are inhomogeneously distributed. Nanobeam electron diffraction confirmed that the crystal structure of the tungsten particles are body-centered cubic, and imply that the structure remains unchanged despite the numerous complex chemical reactions that take place throughout the impregnation and activation procedures. The role of Sc and the emission mechanism for scandate cathodes are discussed. Based on characterization results and materials computation, the role of Sc in scandate cathodes is possibly related to tuning the partial pressure of oxygen in order to establish an oxygen-poor atmosphere around the cathode surface, which is a necessary condition for the formation of the (near) equilibrium tungsten shape. A thin Ba-Sc-O surface layer (~8 nm) was detected near the surface of tungsten particles, using electron energy loss spectroscopy in the scanning transmission electron microscope. This stands in stark contrast to models invoking a ~100 nm Ba-Sc-O semiconducting surface layer, which are broadly discussed in the literature. These results provide new insights into understanding the emission mechanism of scandate cathodes.

Finding what is alike among the personalities of creative people has been a dream of many researchers. No single personality type has been discovered as prototypical, yet the promise of common attributes among creative people remains enticing. This study examines one of these promising characteristics - Openness to Experience, a personality factor from the Five-Factor Model. This factor has been shown to correlate positively with creativity in past studies. In the present study this relationship was partially confirmed in a sample of employees whose jobs require technical problem solving, by correlating the employees self-rated Work-specific Openness to Experience and NEO PI-R Openness with supervisory ratings of their creative work performance. The Work-specific Openness scale demonstrated a significant correlation with supervisory ratings of creativity, whereas the NEO PI-R Openness scale did not. Although none of the NEO PI-R facets were significant predictors of criterion, four Work-specific facets were significant predictors based on zero order correlations. These facets are Openness to Ideas, Fantasy, Values, and Actions. However, although individual facets of Openness were expected to differ in validity, the magnitude of their correlations with creative performance scores did not differ significantly. Convincing results showing incremental validity of the Work-specific scale over the NEO PI-R scale are also discussed.

In 2003, Gomory and Johnson gave two different three-slope T-space facet constructions, both of which shared a slope with the corresponding Gomory mixed-integer cut. We give a new three-slope facet which is independent of the GMIC and also give a four-slope T-space facet construction, which to our knowledge, is the first four-slope construction. We describe an enumerative framework for the discovery of T-space facets. Using an algorithm by Harvey for computing integer hulls in the plane, we give a heuristic for quickly computing lattice-free triangles. Given two rows of the tableau, we derive how to exactly calculate lattice-free triangles and quadrilaterals in the plane which can be used to derive facet-defining inequalities of the integer hull. We then present computational results using these derivations where non-basic integer variables are strengthened using Balas-Jeroslow lifting.

Cet essai a pour objet le rôle de la notion de fiction dans les domaines de l’art et de la science. Essentiellement, je soutiens que « fiction » dans ce contexte est « a category mistake » (concept versus genre) et je crois que cet essai peut réussir à « cuire du pain philosophique » en dévoilant une dispute verbale. Je suggère donc de clore un débat philosophique dans son intégralité. Je présente un exposé du style de fictionnalisme abordé par Catherine Z. Elgin et Nelson Goodman (que ce soit dans le contexte des arts ou des sciences, nous parvenons à la compréhension grâce à des fictions sous formes de « vérités non littérales ») et j’explore le concept de la fiction. Je soutiens que les représentations (textes descriptifs de toutes sortes, incluant les modèles) sont constituées d’éléments fictionnels et d’éléments facettés (à l’exception de la version idéale possible ou impossible, c’est-à-dire dans l’esprit de Dieu, qui n’inclurait que les facettes.) La compréhension ne peut provenir de la fiction, mais plutôt d’éléments facettés ordonnés de manière à créer une compréhension qui conduit généralement à des prédictions, des explications et des manipulations. Je définis les facettes comme ayant des caractéristiques organisées, alors que les fictions ont des caractéristiques désorganisées. La fiction dans son intégralité est donc, par définition, l’expression du néant (of nothing), ou en matière de langues idéales (mathématiques), l’expression de contradiction. Les fictions et les facettes relèvent des représentations qui sont elles-mêmes primitives. Les textes descriptifs sont donc fictionnels par degré. Les récits qui sont très fictionnels ont une certaine valeur (souvent ludique) mais contiennent toujours au moins une facette. En fin de compte, toutes les activités représentationnelles devraient être considérées irréelles, incomplètes, bien que parfois connectées à la réalité, c’est-à-dire, prises entre une description réaliste facettée et une fiction dans son intégralité. / This essay concerns fiction in art and science. I argue that the term ‘fiction’ used in this manner is a category mistake (concept versus genre) and I believe this essay may succeed in “baking philosophical bread” by recognizing a verbal dispute. I am, therefore, suggesting an entire thread of discussion be re-evaluated. I provide an exposé of Catherine Z. Elgin and Nelson Goodman’s brand of fictionalism (i.e. that we glean understandings in the arts and sciences from fictions in the form of non-literal truth) and concentrate on unpacking the concept of fiction. I argue that representations (narratives of all sorts including models) are made of both fictional elements and faceted elements (with the exception of the possible or impossible ideal version e.g. God’s, which, would include only facets). Understandings are not gleaned from fictions but rather from faceted elements so ordered as to create understanding and usually leading to predictions, explanations, and manipulations. I define facets as ordered features whereas fictions (the genre) are groupings of disordered features. Full fiction is, therefore, by definition the expression of nothing or with respect to ideal languages (mathematics), the expression of contradiction. Representations are primitives and both fictions and facets are parts of them. Narratives are thus fictional by degree. Narratives which are highly fictional are of value (often playful) but they still always contain at least one facet. Ultimately all representational activity should be regarded as irreal i.e. incomplete although sometimes connected to reality and caught between a perfectly faceted realist description and complete fiction.

Although the literature indicates that knowledge sharing (KS) research is prevalent in the private sector, there is scant empirical research data about KS in the public sector. Moreover, organizations lack an understanding of employee KS behavior. This study investigated two research questions: First, how does the perceived importance of five determinants of KS behavior (organizational culture, workplace trust, incentives, management support, and technology) vary based upon the variables of job function, gender, and work category? Second, what is the relative importance of the five determinants of KS behavior to U.S. federal government employees? This descriptive study employed a Web-based survey methodology and interviews to collect data. The survey was administered to 121 employees in a single U.S. government organization, with a response rate of 69%. The Statistical Package for the Social Sciences was used for data analysis, and the multivariate analysis of variance and analysis of variance statistical techniques were used to compare variables. The study findings indicated no statistical differences in perceptions of the five facets investigated relative to the variables of work category, gender, and job function, and no statistical differences in the importance among the five determinates investigated. As a result, the null hypotheses were not rejected. Additional findings were that respondents perceived the five facets investigated to be positive KS determinants and that they agreed or strongly agreed that each facet was important to the success of KS initiatives. Although the results indicated no statistically significant difference between the five facets investigated, the results support literature findings that the five facets are important to the KS process. The investigation also advances the current state of KS implementation in the public sector by providing empirical data on a subject that is rarely investigated in the U.S. federal government. Future studies in similar and larger organizations are recommended. The investigation is a positive step toward improving the understanding of the determinants that affect employee KS behavior and provides a tool for KS planners to use to ascertain the state of KS in their organizations.

The dissertation is devoted to analysis of current practice and trends in providing repositories of electronic theses and dissertation (ETDs) in terms of their management, searching and dissemination. The first part presents terminology and the current state of access to ETDs in Czech and foreign repositories and includes results of a survey of the state of access to ETDs in the Czech Republic which was completed in 2014 by all public universities. In the second part, a metadata standard is presented, particularly the possibility of mapping EVSKP-MS metadata elements to other metadata formats and utilization within the OAI-PMH protocol. The issue of access to ETDs is dealt with further in terms of metrics for an evaluation of usage of distributed ETDs. Searching for ETDs is also described in case studies as are recommendations for public tenders for a discovery service and for creating an ETD metadata search server and an associated user interface with faceted search. The final part of the thesis focuses on the issue of plagiarism. This incorporates a presentation and analysis of the most important plagiarism detection systems and a case study of the development of the portal Validátor VŠE to provide access to results of document analysis.

Numerous paleontologists have noted wear facets on tyrannosaurid lateral teeth over the past century. While several workers have proposed explanations for these features, there remains to this day no consensus concerning their etiology. Here we report on an examination of wear surfaces on these teeth from the Upper Cretaceous (mid-Campanian) Judith River Group of southern Alberta, Canada. This study reveals two distinct types of wear features on the labial and lingual sides of tyrannosaurid lateral teeth: irregular "spalled" surfaces and wear facets. The irregular spalled surfaces typically extend to the apex of the tooth, which evidently reflects flaking of enamel resulting from forces produced during contact between tooth and food. These surfaces are often rounded, presumably from antemortem wear following spalling. Wear striations on these surfaces are oriented heterogeneously. The wear facets, in contrast, occur on only one side of the tooth and are typically elliptical in outline and evince parallel wear striations. Similar patterns of parallel wear striations in extant mammals reflect tooth-tooth contact. We therefore propose that wear facets in tyrannosaurids were formed by repeated tooth-tooth contact between the lingual side of maxillary teeth and labial side of dentary teeth. It remains unclear whether this contact was serendipitous or adaptive, though it appears to be unusual for reptiles, as we have found no evidence for wear facets in extant varanids and crocodilians.

The purpose of this phenomenological study was to explore educator understanding of concepts in the Individuals with Disabilities Education Act (IDEA), utilizing qualitative research methods to comprehensively examine educators’ understanding of IDEA using the six facets of understanding in the Understanding by Design framework. Educators must adhere to laws governing educating students with disabilities; therefore, it is essential to capture educators’ level of understanding related to IDEA. The twelve participants interviewed were educators currently licensed and qualified in Tennessee to serve in the roles of: special education supervisor, principal, general education teacher or special education teacher. Data collection strategies included individual interviews via phone. Responses were first organized by research questions and corresponding responses. Responses were then examined for key words and phrases that aligned with the six principles of IDEA. Then, emergent themes were identified and analyzed within the six facets of understanding framework. The credibility of the analysis was protected by use of the constant-comparative method, as well as coding and member checking. Analysis of the data revealed that participants understood the spirit of IDEA, but the level of understanding necessary to be able to apply IDEA concepts was dependent on participants’ specific job responsibilities. Furthermore, research indicated that educators’ personal college preparation experience failed to consistently provide an adequate foundation related to defining and applying IDEA concepts in learning environments for students with disabilities. Participants who possessed the most comprehensive understanding of IDEA were those who had familial ties to students with disabilities. Educators’ understanding of the proper application of IDEA came from on-the-job experiences, which would help to explain why understanding of IDEA was largely dependent upon educators’ specific job functions.

(1) Background: From a young age, boys are more often affected by tooth wear than girls. This suggests an influence of the male sex hormone (testosterone) on the aetiology of tooth wear. The aim of the present study was to investigate the incidence of tooth wear in relation to steroid hormone levels in children. (2) Methods: 1022 test persons aged between 10 and 18 (491 male, 531 female) from the LIFE Child study underwent medical and dental examination. Tooth wear was measured through clinical inspection. Blood samples were taken to determine hormone levels (testosterone, SHBG). The level of free testosterone was calculated from the ratio of testosterone to SHBG. Using multivariable methods, the incidence of tooth wear was analyzed as a function of hormone levels, while controlling for confounders such as age, sex, social status, and orthodontic treatment. (3) Results: The incidence of tooth wear increased with age in both sexes. Boys showed significantly more often attrition facets than girls (17.5% vs. 13.2%, p < 0.001). Subjects with tooth wear showed significantly higher free testosterone levels than those without (males: p < 0.001, females: p < 0.05). After controlling for confounding variables, the risk of tooth wear increased by approximately 30.0% with each year of life (odds ratio [OR]boys = 1.29, 95% confidence interval [CI] = 1.04–1.56; [OR]girls = 1.32, 95% CI = 1.08–1.61). In addition, the risk of tooth wear increased by 6.0% per free testosterone scale score only in boys (OR = 1.06, 95% CI = 1.01–1.12). (4) Conclusions: Tooth wear is common in children and in adolescents, and it increases steadily with age in both sexes. The stronger increase and the higher prevalence among male adolescents can be explained by the additional effect of free testosterone.

<p>The Tirumantiram is a three thousand verse Tamil manual of Āgamic Śaivism composed about the seventh century A.D. by a yogī sage known as Tirumūlar. This work I was accepted into the canonical collection of Śaiva devotional works known as the Tirumuṟai, and can be shown to have significantly influenced the writers of the later canonical collection of Śaiva philosophical texts. Still, the Tirumantiram remains little known outside of South India and even less understood. Both Indian and Western scholars have tended to ignore this work which they commonly characterize as being obscure, opaque and esoteric. While acknowledging the presence of obscure verses and coded portions of the text dealing with advanced yogic instruction, it is my intention to show (a) that the Tirumantiram was composed for a wide-ranging audience of householders and rulers as well as learned Brahmins and trained yogis, and (b) that the aim was to reconcile tensions existing between various Southern Śaiva sects. I will also argue that Tirumūlar sought to accomplish this task by creatively explicating the metaphysical, moral and mystical aspects of Āgamic Śaivism with the aid of mythic figures in order to communicate his insights on a more popular level.</p> <p>The mythic references incorporated into the text lend themselves to being studied under three general exegetical headings. That is, they can be distinguished as having an apologetic, tropological or anagogical thrust corresponding to the three facets of Śaivism mentioned above. In the process of analyzing the mythic imagery and indicating how it was skillfully employed to develop major themes which are reiterated on a more advanced level in other portions of the text, it should become clear that, on the whole, the Tirumantiram was a unified composition and not a mere compilation of solitary verses as has been suggested by K. Zvelebil and others. To my knowledge, this is the most protracted study of the Tirumantiram in English since A. Visvanatha Pillai produced his translation and commentary on several hundred selected verses in the mid 1960's.</p> <p>The numbering of Tirumantiram verses cited or quoted in this study follows that found in G. Varadarajan's Edition. The latter was chosen because it is both reliable and more readily available than other responsible editions. For words I have followed the form of transliteration adopted by standard works on Indology. As for the transliteration of Tamil, several systems are currently in use. Here I will follow that set forth in the Madras Tamil Lexicon.</p> / Doctor of Philosophy (PhD)