Dear Wife : the Civil War letters of Chester K. Leach

Occasional paper (University of Vermont. Center for Research on Vermont) ; no. 20

Evidence for early Mesoproterozoic arc magmatism in the Musgrave Block, central Australia: Implications for Proterozoic crustal growth and tectonic reconstructions of Australia

The Musgrave Block in central southern Australia separates the dominantly Paleoproterozoic North Australian Craton from the Late Archean to early Mesoproterozoic Gawler Craton in southern Australia. Geochemical and Nd isotopic data from ∼1.59–1.55-Ga felsic rocks in the Mann Ranges suggest that the early history of the Musgrave Block was linked to the development of subduction along the northern margin of the Gawler Craton. Characteristic geochemical patterns of these felsic rocks include negative anomalies in Nb, Ti, and Y and are accompanied by steep light rare earth element patterns and comparatively juvenile Nd isotopic compositions (εNd(1550) values from -1.2 to 0.9). The geochemical and isotopic signatures of these early Mesoproterozoic felsic rocks have similarities with island arc systems involving residual Ti-bearing minerals and garnet. We propose that the 1.59–1.55-Ga arclike rocks in the Musgrave Block indicate the presence of an active margin between the North Australian Craton and the South Australian Craton, with subsequent suturing of the Australian continent during the early Mesoproterozoic. The existence of arclike magmatism in the Musgrave Block during the early Mesoproterozoic suggests a period of major crustal growth in the Australian Proterozoic that has important implications for current Proterozoic reconstructions of Australia and Australia’s fit within the supercontinent Rodinia.B. P. Wade, K. M. Barovich, M. Hand, I. R. Scrimgeour and D. F. Clos

Evidence for early Mesoproterozoic arc magmatism in the Musgrave Block, central Australia: Implications for Proterozoic crustal growth and tectonic reconstructions of Australia

The Musgrave Block in central southern Australia separates the dominantly Paleoproterozoic North Australian Craton from the Late Archean to early Mesoproterozoic Gawler Craton in southern Australia. Geochemical and Nd isotopic data from ∼1.59–1.55-Ga felsic rocks in the Mann Ranges suggest that the early history of the Musgrave Block was linked to the development of subduction along the northern margin of the Gawler Craton. Characteristic geochemical patterns of these felsic rocks include negative anomalies in Nb, Ti, and Y and are accompanied by steep light rare earth element patterns and comparatively juvenile Nd isotopic compositions (εNd(1550) values from -1.2 to 0.9). The geochemical and isotopic signatures of these early Mesoproterozoic felsic rocks have similarities with island arc systems involving residual Ti-bearing minerals and garnet. We propose that the 1.59–1.55-Ga arclike rocks in the Musgrave Block indicate the presence of an active margin between the North Australian Craton and the South Australian Craton, with subsequent suturing of the Australian continent during the early Mesoproterozoic. The existence of arclike magmatism in the Musgrave Block during the early Mesoproterozoic suggests a period of major crustal growth in the Australian Proterozoic that has important implications for current Proterozoic reconstructions of Australia and Australia’s fit within the supercontinent Rodinia.B. P. Wade, K. M. Barovich, M. Hand, I. R. Scrimgeour and D. F. Clos

Nanosecond laser texturing for high friction applications

AbstractA nanosecond pulsed Nd:YAG fibre laser with wavelength of 1064nm was used to texture several different steels, including grade 304 stainless steel, grade 316 stainless steel, Cr–Mo–Al ‘nitriding’ steel and low alloy carbon steel, in order to generate surfaces with a high static friction coefficient. Such surfaces have applications, for example, in large engines to reduce the tightening forces required for a joint or to secure precision fittings easily. For the generation of high friction textures, a hexagonal arrangement of laser pulses was used with various pulse overlaps and pulse energies. Friction testing of the samples suggests that the pulse energy should be high (around 0.8mJ) and the laser pulse overlap should be higher than 50% in order to achieve a static friction coefficient of more than 0.5. It was also noted that laser processing increases the surface hardness of samples which appears to correlate with the increase in friction. Energy-Dispersive X-ray spectroscopy (EDX) measurements indicate that this hardness is caused by the formation of hard metal-oxides at the material surface

On the combination of omics data for prediction of binary outcomes

Enrichment of predictive models with new biomolecular markers is an important task in high-dimensional omic applications. Increasingly, clinical studies include several sets of such omics markers available for each patient, measuring different levels of biological variation. As a result, one of the main challenges in predictive research is the integration of different sources of omic biomarkers for the prediction of health traits. We review several approaches for the combination of omic markers in the context of binary outcome prediction, all based on double cross-validation and regularized regression models. We evaluate their performance in terms of calibration and discrimination and we compare their performance with respect to single-omic source predictions. We illustrate the methods through the analysis of two real datasets. On the one hand, we consider the combination of two fractions of proteomic mass spectrometry for the calibration of a diagnostic rule for the detection of early-stage breast cancer. On the other hand, we consider transcriptomics and metabolomics as predictors of obesity using data from the Dietary, Lifestyle, and Genetic determinants of Obesity and Metabolic syndrome (DILGOM) study, a population-based cohort, from Finland

On the regularization scheme and gauge choice ambiguities in topologically massive gauge theories

It is demonstrated that in the (2+1)-dimensional topologically massive gauge theories an agreement of the Pauli-Villars regularization scheme with the other schemes can be achieved by employing pairs of auxiliary fermions with the opposite sign masses. This approach does not introduce additional violation of discrete (P and T) symmetries. Although it breaks the local gauge symmetry only in the regulator fields' sector, its trace disappears completely after removing the regularization as a result of superrenormalizability of the model. It is shown also that analogous extension of the Pauli-Villars regularization in the vector particle sector can be used to agree the arbitrary covariant gauge results with the Landau ones. The source of ambiguities in the covariant gauges is studied in detail. It is demonstrated that in gauges that are softer in the infrared region (e.g. Coulomb or axial) nonphysical ambiguities inherent to the covariant gauges do not arise.Comment: Latex, 13 pages. Replaced mainly to change preprint references to journal one

Two-stage potassium test turbine. Volume 4 - Materials support of performance and endurance tests

Two stage potassium vapor turbine - materials support of performance and endurance test

Symmetric and asymmetric action integration during cooperative object manipulation in virtual environments

Cooperation between multiple users in a virtual environment (VE) can take place at one of three levels. These are defined as where users can perceive each other (Level 1), individually change the scene (Level 2), or simultaneously act on and manipulate the same object (Level 3). Despite representing the highest level of cooperation, multi-user object manipulation has rarely been studied. This paper describes a behavioral experiment in which the piano movers' problem (maneuvering a large object through a restricted space) was used to investigate object manipulation by pairs of participants in a VE. Participants' interactions with the object were integrated together either symmetrically or asymmetrically. The former only allowed the common component of participants' actions to take place, but the latter used the mean. Symmetric action integration was superior for sections of the task when both participants had to perform similar actions, but if participants had to move in different ways (e.g., one maneuvering themselves through a narrow opening while the other traveled down a wide corridor) then asymmetric integration was superior. With both forms of integration, the extent to which participants coordinated their actions was poor and this led to a substantial cooperation overhead (the reduction in performance caused by having to cooperate with another person)

Sixth-Order Vacuum-Polarization Contribution to the Lamb Shift of the Muonic Hydrogen

The sixth-order electron-loop vacuum-polarization contribution to the $2P_{1/2} - 2S_{1/2}$ Lamb shift of the muonic hydrogen ($\mu^{-} p^+$ bound state) has been evaluated numerically. Our result is 0.007608(1) meV. This eliminates the largest uncertainty in the theoretical calculation. Combined with the proposed precision measurement of the Lamb shift it will lead to a very precise determination of the proton charge radius.Comment: 4 pages, 5 figures the totoal LS number is change

The GDH Sum Rule and Related Integrals

The spin structure of the nucleon resonance region is analyzed on the basis of our phenomenological model MAID. Predictions are given for the Gerasimov-Drell-Hearn sum rule as well as generalized integrals over spin structure functions. The dependence of these integrals on momentum transfer is studied and rigorous relationships between various definitions of generalized Gerasimov-Drell-Hearn integrals and spin polarizabilities are derived. These results are compared to the predictions of chiral perturbation theory and phenomenological models.Comment: 15 pages LaTeX including 5 figure