The Historical and Modern Significance of the Choctaw Hymnody

Working with the Native Choctaw populations of early America, missionaries did much in the way of music and composition. One result was a compilation of original hymns written by English missionaries in the native Choctaw tongue, but there were also Choctaw composers and contributions. Singing these hymns in church services, gatherings, and social situations remains an activity where the Oklahoma and Mississippi tribal members participate today. The recorded history of the known hymns and composers is scarce and is disappearing daily in favor of teaching the ancient cultures rather than the religion of the white colonists. The research chose a qualitative method to study the lives, backgrounds, and motivations of the Choctaw composers of these hymns. The study further employed a form of historical observation to examine the members of the tribe who promoted the hymns throughout the community and the white missionaries that collaborated with them to translate the hymns into their original tongue. Little has been written or published regarding hymns in the Choctaw language. A few writings on the subject exist from the 1940s and the 1970s. The study should specifically target the Choctaw community by reevaluating the origins of these hymns and their place in modern and historical Choctaw culture. Additionally, the results of such an investigation should benefit and further other studies into Native American cultures of various tribes and the outside and inside influences regarding Christianity and musicality within those tribal cultures

Growth, Characterization, and Electrochemical Properties of Doped n-Type KTaO_3 Photoanodes

The effects of compositionally induced changes on the semiconducting properties, optical response, chemical stability, and overall performance of KTaO_3 photoanodes in photoelectrochemical (PEC) cells have been investigated. Single crystals of n-type Ca- and Ba-doped KTaO_3 with carrier concentrations ranging from 0.45 to 11.5×10^(19) cm^(−3) were grown and characterized as photoanodes in basic aqueous electrolyte PEC cells. The PEC properties of the crystals, including the photocurrent, photovoltage, and flatband potential in contact with 8.5 M NaOH(aq) were relatively independent of whether Ca or Ba was used to produce the semiconducting form of KTaO_3. All of the Ca- or Ba-doped KTaO_3 single-crystal photoanodes were chemically stable in the electrolyte and, based on the open-circuit potential and the band-edge positions, were capable of unassisted photochemical H_2 and O_2 evolution from H_2O. The minority-carrier diffusion lengths values were small and comparable to the depletion region width. Photoanodic currents were only observed for photoanode illumination with light above the bandgap (i.e., λ<340 nm). The maximum external quantum yield occurred at λ=255 nm (4.85 eV), and the depletion width plus the minority-carrier diffusion length ranged from 20 to 65 nm for the various KTaO_3-based photoanode materials

Lanthanide orthophosphates as a matrix for solidified radioactive defense and reactor wastes

Lanthanum phosphate is a promising host material for reprocessed light water reactor wastes (e.g., PW-4b). This is demonstrated by the high density of the composite waste form and by the low leach rates of both Cs and Sr. Additionally, crystallographic data on LaPO/sub 4/ pellets loaded with 10 wt % simulated PW-4b indicate the presence of only one phase, i.e., monoclinic monazite. The rare-earth orthophosphates have also been shown to be a viable waste form for Savannah River (SRW) defense wastes. Compaction and sintering studies indicate that the rare-earth phosphate mixture employed here is preferable to pure LaPO/sub 4/ for containing SRW. Higher density and more homogeneous samples were obtained by using the mixed phosphates as compared to pure LaPO/sub 4/ as the host material. It is shown that aluminum removal from the composite SRW is not necessary when incorporating this type of waste into a rare-earth phosphate host. The current results support the view that lanthanide orthophosphate waste forms (i.e., monazite) are potentially superior to borosilicate glasses in the following respects: (1) lower processing temperatures (approx. 1000/sup 0/C versus 1160/sup 0/C for glass); (2) significantly higher waste per volume loadings for a given wt % of waste for monazites relative to glass; and (3) the current leaching data show that monazite-type waste forms are clearly superior to glass in retaining Sr, and, in particular, Cs

X-ray photoelectron spectroscopy study of irradiation-induced amorphizaton of Gd2Ti2O7Gd2Ti2O7

The radiation-induced evolution of the microstructure of Gd2Ti2O7,Gd2Ti2O7, an important pyrochlore phase in radioactive waste disposal ceramics and a potential solid electrolyte and oxygen gas sensor, has been characterized using transmission electron microscopy and x-ray photoelectron spectroscopy. Following the irradiation of a Gd2Ti2O7Gd2Ti2O7 single crystal with 1.5 MeV Xe+Xe+ ions at a fluence of 1.7×1014 Xe+/cm2,1.7×1014Xe+/cm2, cross-sectional transmission electron microscopy revealed a 300-nm-thick amorphous layer at the specimen surface. X-ray photoelectron spectroscopy analysis of the Ti 2p2p and O 1s1s electron binding energy shifts of Gd2Ti2O7Gd2Ti2O7 before and after amorphization showed that the main results of ion-irradiation-induced disorder are a decrease in the coordination number of titanium and a transformation of the Gd–O bond. These features resemble those occurring in titanate glass formation, and they have implications for the chemical stability and electronic properties of pyrochlores subjected to displacive radiation damage. © 2001 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71018/2/APPLAB-79-13-1989-1.pd

Simultaneous formation of surface ripples and metallic nanodots induced by phase decomposition and focused ion beam patterning

We report the simultaneous formation of self-assembled surface ripples in Cd2Nb2O7Cd2Nb2O7 pyrochlore caused by focused ion beam (FIB) patterning and uniformly distributed metallic nanodots induced by phase decomposition under ion bombardment. The characteristic wavelength of the surface ripples is controllable from the nm to the sub-μmsub-μm scale. High-density Cd metallic nanoparticles, ∼ 5 nm∼5nm, formed and the distribution of nanoparticles is consistent with the morphological characteristics of the ripple pattern. This approach provides a means of fabricating surface nanostructure with various patterns and a controllable particle size and distribution by combining ion beam-induced phase decomposition with high-precision FIB patterning.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87787/2/093112_1.pd

EPR investigations of impurities in the lanthanide orthophosphates

Lanthanide orthophosphates formed from elements in the first half of the 4f transition series are analogs of the monoclinic mineral monazite. The known geologic properties of this mineral make the general class of lanthanide orthophosphate compounds attractive substances for long-term containment and disposal of ..cap alpha..-active actinide nuclear wastes. EPR spectroscopy has been used to investigate the structural properties and solid state chemical properties of impurities in these materials and to compare the characteristics of single crystals and polycrystalline bodies

Ion Beam-Induced Changes in Optical Properties of MgO

The implantation of Ag into MgO (100) single crystals, followed by thermal annealing at 1,100 C, leads to dramatic changes in their optical properties. The changes in the optical properties are due to the presence of small Ag clusters which are formed in the annealed samples. The small Ag clusters are obtained by thermal annealing of the implanted MgO crystals between 600 C and 1,100 C to investigate the changes in cluster sizes and to correlate with changes in their optical properties. Sample characterization is carried out using optical spectrophotometry to confirm the effective presence of Ag clusters and Rutherford Backscattering Spectrometry (RBS) to study the profile of Ag clusters

Analysis of ripple formation in single crystal spot welds

Stationary spot welds have been made at the (001) surface of Fe-l5%Ni-15%Cr single crystals using a Gas Tungsten Arc (GTA). On the top surface of the spot welds, very regular and concentric ripples were observed after solidification by differential interference color microscopy. Their height (typically 1--5 {micro}m) and spacing (typically {approximately} 60 {micro}m) decreased with the radius of the pool. These ripples were successfully accounted for in terms of capillary-wave theory using the fundamental mode frequency f{sub 0} given by the first zero of the zero-order Bessel function. The spacing d between the ripples was then equated to v{sub s}/f{sub 0}, where v{sub s} is the solidification rate. From the measured ripple spacing, the velocity of the pool was deduced as a function of the radius, and this velocity was in good agreement with the results of a heat-flow simulation