The Effects of Time Dependent Stress-Path on The Plastic and Elastic Deformation of Sand and Clay Soils Subjected to Dynamic Loading

Cylindrical cyclic loading tests were used to study the effects of time dependent stress path on the plastic and elastic deformations of sand and clay soil samples. The test materials were obtained from the subgrade of existing highway pavements located throughout the state of Michigan. Approximately, 25 cylindrical soil samples (13.5 cm long, 5.5 cm in diameter) were tested under repeated loading conditions using different hydrostatic confining pressures and several time dependent stress-paths. In all tests, the first invariant of the stress tensor was cycled between two constant values and the first invariant of the stress deviator tensor was increased incremently and cycled such that its minimum value was kept greater than 6.895 kPa. at all times. Analysis of the test results indicated several findings, these include: 1) Increasing the first invariant of the stress deviator tensor with time,for sand samples, decreased the average rate and magnitude of the plastic deformation of the samples. 2) For clay samples, the rate and magnitude of the plastic and elastic deformations were found to be dependent on the first invariants of the stress tensor and stress deviator tensor, on the stresspath and on the sample parameters. For example, the elastic strains of two duplicate soil samples tested under the same stress conditions (same invariants of stress tensor and stress deviator tensor) were different by a factor of 2 to 100. The value of this factor was found to be a function of the time dependent stress path

Precision Measurement of The Most Distant Spectroscopically Confirmed Supernova Ia with the Hubble Space Telescope

We report the discovery of a redshift 1.71 supernova in the GOODS North field. The Hubble Space Telescope (HST) ACS spectrum has almost negligible contamination from the host or neighboring galaxies. Although the rest frame sampled range is too blue to include any Si ii line, a principal component analysis allows us to confirm it as a Type Ia supernova with 92% confidence. A recent serendipitous archival HST WFC3 grism spectrum contributed a key element of the confirmation by giving a host-galaxy redshift of 1.713 +/- 0.007. In addition to being the most distant SN Ia with spectroscopic confirmation, this is the most distant Ia with a precision color measurement. We present the ACS WFC and NICMOS 2 photometry and ACS and WFC3 spectroscopy. Our derived supernova distance is in agreement with the prediction of LambdaCDM.Comment: 13 pages, 6 figures, published in ApJ with updated analysi

The Petrology and Stratigraphy of the Portland Hills Silt

Topics in geology, which inevitably excite professional discussion and even tempered debate, often present challenging targets for the exploratory jabs of Master\u27s degree candidates. The Portland Hills Silt and the controversy concerning its genesis provides just such an object. Although the physical descriptions of the silt are generally in agreement, they remain somewhat generalized and, at present, no single definition is generally accepted. Moreover, incongruities concerning structural and textural details--notably, the presence of minor stratification and/or scattered pebbles in the silt--have resulted in considerable disagreement regarding its mode of origin

Whole-exome sequencing in evaluation of patients with venous thromboembolism

Genetics play a significant role in venous thromboembolism (VTE), yet current clinical laboratory-based testing identifies a known heritable thrombophilia (factor V Leiden, prothrombin gene mutation G20210A, or a deficiency of protein C, protein S, or antithrombin) in only a minority of VTE patients. Wehypothesized that a substantial number of VTE patients could have lesser-known thrombophilia mutations. To test this hypothesis, we performed whole-exome sequencing (WES) in 64 patients with VTE, focusing our analysis on a novel 55-gene extended thrombophilia panel that we compiled. Our extended thrombophilia panel identified a probable disease-causing genetic variant or variant of unknown significance in 39 of 64 study patients (60.9%), compared with 6 of 237 control patients without VTE (2.5%) (P 1 variant. Sanger sequencing performed in family members of 4 study patients with and without VTE showed generally concordant results with thrombotic history. WES and extended thrombophilia testing are promising tools for improving our understanding of VTE pathogenesis and identifying inherited thrombophilias.C.R.P. was supported by the National Health and Medical Research Council of Australia. A.R.R. was supported by the National Institutes of Health, National Heart, Lung, and Blood Institute R01 HL062565