William Widgeon bill for sowing 18 acres with clover seed, 1831

William Widgeon is paid $1.35 for sowing 18 acres with clover seed at 7.5 cents per acre. 7.75" X 3.75

Remaking respectability: African-American women and the politics of identity in interwar Detroit.

This dissertation traces the ways in which African-American women in Detroit negotiated community and individual identity from the Great Migration through the Great Depression. Divergent notions of appropriate behavior and deportment shaped the actions and interactions of elite and working-class African-American women during this period. Respectability, in particular, was a language and set of practices that had different meanings for different groups of women as African-Americans moved to Northern cities during the Great Migration. During the 1910s and 1920s Detroit's African-American reformers relied on images of "respectable" women to promote a community identity through public displays of "proper" dress and deportment. Meanwhile, individual female migrants engaged in activities that crossed lines of "rough" and "respectable" as they negotiated an urban terrain of saloons, disorderly houses and dance halls as well as settlement houses, churches and training centers. By the 1930s, dominate notions of African-Americans were "remade" as reformers focused less on religious and moral codes based on female respectability, and more on the employment of African-American men, youth delinquency, and the struggle for civil rights. In most narratives of the Great Migration, the African-American male industrial worker has been the central protagonist. Contemporaries of that migration, however, viewed female migrants as "seeds" of a new Northern community, carrying morality, education, and religiosity to the homes that would form the center of African-American urban neighborhoods. This dissertation rewrites early twentieth-century African-American history by placing women at the center of the story of migration and the growth of new urban African-American communities. In the field of women's history, the story of African-American women has not focused on the crucial inter-war period when reformers and migrants struggled with the relationship between gender roles, and community building. Thus, this dissertation fills a major lacuna in both African-American and Women's history by tracing the movement of southern African-American women to Detroit, and examining how a reform discourse of female respectability shaped the institutional responses to the Great Migration.Ph.D.HistoryUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/104886/1/9610269.pdfDescription of 9610269.pdf : Restricted to UM users only

Spectroscopic and calorimetric investigation of short and intermediate-range structures and energetics of amorphous SiCO, SiCN, and SiBCN polymer-derived ceramics

Polymer-derived ceramics (PDCs) are a new class of amorphous ceramics in the Si-B-C-N system that are synthesized by the pyrolysis of silicon-based organic polymers. PDCs are lightweight and are resistant to creep, crystallization, and oxidation at temperatures near 1800 K making them ideal for a variety of high temperature applications. In spite of being X-ray amorphous, these materials display structural heterogeneity at the nanometer length scale. Their structure and resulting properties can be drastically altered by the utilization of preceramic polymers with differing chemistry and architectures. Fundamental understanding of the atomic structure is critical in deciphering the structure-property relationships and ultimately in controlling their properties for specific engineering applications. The short-range atomic structure has been extensively investigated using a variety of techniques, however, the structures at length scales beyond next-nearest neighbors remained highly controversial. Here we report the results of a spectroscopic and calorimetric study of short and intermediate -range structure and energetic of SiOC and SiBCN PDCs derived from a wide variety of precursors. SiOC PDCs with different carbon contents were synthesized from polysiloxane precurors and their structures were studied using high-resolution 13C and 29Si nuclear magnetic resonance (NMR) spectroscopy. The results suggest that these PDCs consists of a continuous mass fractal backbone of corner-shared SiC xO4-x tetrahedral units with "voids" occupied by sp 2-hybridized graphitic carbon. The oxygen-rich SiCxO 4-x units are located at the interior of this backbone with a mass fractal dimension of ~ 2.5, while the carbon-rich units occupy the two-dimensional interface between the backbone and the free carbon nanodomains. Such fractal topology is expected to give rise to unusual mechanical and transport properties characteristic of fractal percolation networks. For example, elastic moduli and transport properties such as electrical conductivity and viscosity may show power-law dependence on composition near and above the percolation threshold of the SiOC network or that of the free-carbon phase. Si(B)CN PDCs with different carbon contents were synthesized by pyrolysis of poly(boro)silylcarbodiimides and poly(boro)silazane precursors and their structure and energetics were studied using multi-nuclear, one- and two- dimensional NMR spectroscopy and oxide melt solution calorimetry. The structure of the polysilylcarbodiimide-derived SiCN PDCs at lower carbon content and pyrolysis temperatures (800 oC) consists of amorphous nanodomains of sp2 carbon and silicon nitride with an interfacial bonding between N, C and Si atoms that is stabilized by the presence of hydrogen. The interfacial Si-C and N-C bonds are destroyed with concomitant hydrogen loss upon increasing the pyrolysis temperature to 1100 oC. Calorimetry results demonstrate that the mixed bonding in the interfacial regions play a key role in the thermodynamic stabilization of these PDCs. The size of the carbon domains increases with increasing carbon content until a continuous amorphous carbon matrix is formed with 55-60 wt % C. The polyborosilylcarbodiimide-derived SiBCN ceramics contain carbon and silicon nitride nanodomains with the BN domains being present predominantly at the interface. In contrast, the structure of the polyborosilazane-derived ceramics consists of significant amount of mixed bonding in the nearest-neighbor coordination environments of Si and B atoms leading to the formation of SiC xN4-x tetrahedral units and BCN2 triangular units. The interfacial region between the SiCN and C nanodomains is occupied by the BCN phase. These results demonstrate that the chemistry of the polymeric precursors exerts major influence on the microstructure and bonding in their derived ceramics

Payment for sowing 35 acres, 1831

William Widgeon is paid $2.62.1/2 for sowing 35 acres with clover seed at .75 for ten acres. received payment in full from Arvine Wales. 5.55" X 3.5

On the Mass Fractal Character of Si-Based Structural Networks in Amorphous Polymer Derived Ceramics

The intermediate-range packing of SiNxC4−x (0 ≤ x ≤ 4) tetrahedra in polysilycarbodiimide and polysilazane-derived amorphous SiCN ceramics is investigated using 29Si spin-lattice relaxation nuclear magnetic resonance (SLR NMR) spectroscopy. The SiCN network in the polysilylcarbodiimide-derived ceramic consists predominantly of SiN4 tetrahedra that are characterized by a 3-dimensional spatial distribution signifying compact packing of such units to form amorphous Si3N4 clusters. On the other hand, the SiCN network of the polysilazane-derived ceramic is characterized by mixed bonded SiNxC4−x tetrahedra that are inefficiently packed with a mass fractal dimension of Df ~2.5 that is significantly lower than the embedding Euclidean dimension (D = 3). This result unequivocally confirms the hypothesis that the presence of dissimilar atoms, namely, 4-coordinated C and 3-coordinated N, in the nearest neighbor environment of Si along with some exclusion in connectivity between SiCxN4−x tetrahedra with widely different N:C ratios and the absence of bonding between C and N result in steric hindrance to an efficient packing of these structural units. It is noted that similar inefficiencies in packing are observed in polymer-derived amorphous SiOC ceramics as well as in proteins and binary hard sphere systems

Study Abroad Student Panel

Sophomore year is the perfect time to think about study abroad, either for the summer or for junior year. Advisors and a diverse student panel (History, Linguistics, Organizational Studies, Sociology and Spanish concentrators) will answer your questions about going abroad through the Office of International Programs (OIP) or through a non-UM program, in-residence and transfer credit, financial aid, and timelines for planning. Find out why students say that their semester or year abroad was the best part of their undergraduate education! Videotaped and edited by Caleb Newman.Advisors provide the nuts and bolts of studying abroad, and a diverse student panel shares their experiences studying abroad.Cosponsored by LSA Academic Advising, the Office of International Programs, the International Center's Education Abroad Office, and LSA Student Government.http://deepblue.lib.umich.edu/bitstream/2027.42/64013/7/6_AfterStudyAbroad.movhttp://deepblue.lib.umich.edu/bitstream/2027.42/64013/6/5_FitIntoProgram.movhttp://deepblue.lib.umich.edu/bitstream/2027.42/64013/5/5_AboutPrograms.movhttp://deepblue.lib.umich.edu/bitstream/2027.42/64013/4/4_TransferringCredits.movhttp://deepblue.lib.umich.edu/bitstream/2027.42/64013/3/3_PreEvalCredits.movhttp://deepblue.lib.umich.edu/bitstream/2027.42/64013/2/2_TypesofPrograms.movhttp://deepblue.lib.umich.edu/bitstream/2027.42/64013/1/1 IntroductionStudy Abroad.mo

Effect of Precursor on Speciation and Nanostructure of SiBCN Polymer-Derived Ceramics

A comparative structural study of silicon borocarbonitride polymer-derived ceramics synthesized using polyborosilylcarbodiimide and polyborosilazane precursors is carried out using high-resolution, multinuclear, one- and two- dimensional NMR spectroscopy. The polyborosilylcarbodiimide-derived ceramics contain relatively pure Si3N4 and C nanodomains with the BN domains being present predominantly at the interface such that the bonding at the interface consists of Si–N–B, Si–N–C, and B–N–C linkages. In contrast, the structure of the polyborosilazane-derived ceramics consists of significant amount of mixed bonding in the nearest-neighbor coordination environments of Si and B atoms leading to the formation of SiCxN4−x (0 ≤ x ≤ 4) tetrahedral units and BCN2 triangular units. The interfacial region between the SiCN and C nanodomains is occupied by the BCN phase. These results demonstrate that the chemistry of the polymeric precursors exerts major influence on the microstructure and bonding in their derived ceramics even when the final chemical compositions of the latter are similar

29Si and13C Solid-State NMR Spectroscopic Study of Nanometer-Scale Structure and Mass Fractal Characteristics of Amorphous Polymer Derived Silicon Oxycarbide Ceramics

Polymer derived silicon oxycarbide ceramics (SiOC-PDCs) with widely different carbon contents have been synthesized, and their structures have been studied at different length scales using high-resolution 13C and 29Si magic-angle-spinning (MAS) NMR spectroscopic techniques. The data suggest that the structure of these PDCs consists of a continuous mass fractal backbone of corner-shared SiCxO4-x tetrahedral units with “voids” occupied by sp2-hybridized graphitic carbon. The oxygen-rich SiCxO4-x units are located at the interior of this backbone with a mass fractal dimension of 2.5 while the carbon-rich units display a slightly lower dimensionality and occupy the interface between the backbone and the free carbon nanodomains

Nanostructure and Energetics of Carbon-Rich SiCN Ceramics Derived from Polysilylcarbodiimides: Role of the Nanodomain Interfaces

SiCN polymer-derived ceramics (PDCs) with different carbon contents have been synthesized by pyrolysis of poly(phenylvinylsilylcarbodiimide) and of poly(phenylsilsesquicarbodiimide), and their structure and energetics have been studied using 29Si, 13C, 15N, and 1H solid state nuclear magnetic resonance (NMR) spectroscopy and oxide melt solution calorimetry. The structure of these PDCs at lower carbon content (35–40 wt %) and pyrolysis temperatures (800 °C) consists primarily of amorphous nanodomains of sp2 carbon and silicon nitride with an interfacial region characterized by mixed bonding between N, C, and Si atoms that is likely stabilized by the presence of hydrogen. The average size of the carbon domains increases with increasing carbon content, and a continuously connected amorphous carbon matrix is formed in PDCs with 55–60 wt % C. The interfacial silicon–carbon and nitrogen–carbon bonds are destroyed with concomitant hydrogen loss upon increasing the pyrolysis temperature to 1100 °C. Calorimetry results demonstrate that the mixed bonding between C, N, and Si atoms in the interfacial regions play a key role in the thermodynamic stabilization of these PDC. They become energetically less stable with increasing annealing temperature and concomitant decrease of mixed bonds and hydrogen loss