2 resultados para primary elements
em Digital Commons at Florida International University
Resumo:
The purpose of this phenomenological study was to understand what impact “heteronormativity” has on a lesbian teacher's perception of her instructional style, content, and context of curriculum taught. Through taped interviews with lesbian educators, this research examined the lived experience of the lesbian teacher. The framework for this study included theories related to historical, sociocultural, and psychosocial development while the methodology included a qualitative design using primary elements of a phenomenological study outlined without ignoring the influence associated with contextualism. Due to the sensitive nature of the study nine women who were the focus of this research were volunteers with the first serving as a “gatekeeper” to assist in the pilot study. The subsequent group evolved as a result of “snowballing” to gain more participants. ^ The data in the form of narrative derived from the interviews was transcribed, color-coded, and organized into four themes and associated sub-themes, based upon the perceptions of these educators. These themes characterized the coming out process of a lesbian, which directly paralleled the personal and professional development of the lesbian educator, emerged as a result of the analysis. They included: (a) self-acknowledgement; (b) self-indentification; (c) coming out to other lesbians by overcoming fear and establishing relationships; (d) coming out to others by overcoming heteronormativity by using support groups in defining a lesbian's role as a teacher. ^ The results of this study showed that the acceptance of the lesbian culture, shared with the acknowledgement, rather than compliance or defiance, of cultural hegemony can allow the lesbian educator to develop a curriculum and a classroom climate that will foster understanding and even generate social change among colleagues, parents, and students, one person at a time. ^
Resumo:
Intraplate volcanism that has created the Hawaiian-Emperor seamount chain is generally thought to be formed by a deep-seated mantle plume. While the idea of a Hawaiian plume has not met with substantial opposition, whether or not the Hawaiian plume shows any geochemical signal of receiving materials from the Earth’s Outer Core and how the plume may or may not be reacting with the overriding lithosphere remain debatable issues. In an effort to understand how the Hawaiian plume works I report on the first in-situ sulfides and bulk rock Platinum Group Element (PGE) concentrations, together with Os isotope ratios on well-characterized garnet pyroxenite xenoliths from the island of Oahu in Hawaii. The sulfides are Fe-Ni Monosulfide Solid Solution and show fractionated PGE patterns. Based on the major elements, Platinum Group Elements and experimental data I interpret the Hawaiian sulfides as an immiscible melt that separated from a melt similar to the Honolulu Volcanics (HV) alkali lavas at a pressure-temperature condition of 1530 ± 100OC and 3.1±0.6 GPa., i.e. near the base or slightly below the Pacific lithosphere. The 187Os/188Os ratios of the bulk rock vary from subchondritic to suprachondritic (0.123-0.164); and the 187Os/188Os ratio strongly correlates with major element, High Field Strength Element (HFSE), Rare Earth Element (REE) and PGE abundances. These correlations strongly suggest that PGE concentrations and Os isotope ratios reflect primary mantle processes. I interpret these correlations as the result of melt-mantle reaction at the base of the lithosphere: I suggest that the parental melt that crystallized the pyroxenites selectively picked up radiogenic Os from the grain boundary sulfides, while percolating through the Pacific lithosphere. Thus the sampled pyroxenites essentially represent crystallized melts from different stages of this melt-mantle reaction process at the base of the lithosphere. I further show that the relatively low Pt/Re ratios of the Hawaiian sulfides and the bulk rock pyroxenites suggest that, upon ageing, such pyroxenites plus their sulfides cannot generate the coupled 186Os- 187Os isotope enrichments observed in Hawaiian lavas. Therefore, recycling of mantle sulfides of pyroxenitic parentage is unlikely to explain the enriched Pt-Re-Os isotope systematics of plume-derived lavas.