Surface Slip During Large Owens Valley Fault Earthquakes

The 1872 Owens Valley earthquake is the third largest known historical earthquake in California. Relatively sparse field data and a complex rupture trace, however, inhibited attempts to fully resolve the slip distribution and reconcile the total moment release. We present a new, comprehensive record of surface slip based on lidar and field investigation, documenting 162 new measurements of laterally and vertically displaced landforms for 1872 and prehistoric Owens Valley earthquakes. Our lidar analysis uses a newly developed analytical tool to measure fault slip based on cross‐correlation of sublinear topographic features and to produce a uniquely shaped probability density function (PDF) for each measurement. Stacking PDFs along strike to form cumulative offset probability distribution plots (COPDs) highlights common values corresponding to single and multiple‐event displacements. Lateral offsets for 1872 vary systematically from ∼1.0 to 6.0 m and average 3.3 ± 1.1 m (2σ). Vertical offsets are predominantly east‐down between ∼0.1 and 2.4 m, with a mean of 0.8 ± 0.5 m. The average lateral‐to‐vertical ratio compiled at specific sites is ∼6:1. Summing displacements across subparallel, overlapping rupture traces implies a maximum of 7–11 m and net average of 4.4 ± 1.5 m, corresponding to a geologic Mw ∼7.5 for the 1872 event. We attribute progressively higher‐offset lateral COPD peaks at 7.1 ± 2.0 m, 12.8 ± 1.5 m, and 16.6 ± 1.4 m to three earlier large surface ruptures. Evaluating cumulative displacements in context with previously dated landforms in Owens Valley suggests relatively modest rates of fault slip, averaging between ∼0.6 and 1.6 mm/yr (1σ) over the late Quaternary

Morphological evolution of electrochemically plated stripped lithium microstructures by synchrotron X ray phase contrast tomography

Due to its low redox potential and high theoretical specific capacity, Li metal has drawn worldwide research attention because of its potential use in next generation battery technologies such as Li S and Li O2. Unfortunately, uncontrollable growth of Li microstructures LmSs, e.g., dendrites, fibers during electrochemical Li stripping plating has prevented their practical commercialization. Despite various strategies proposed to mitigate LmS nucleation and or block its growth, a fundamental understanding of the underlying evolution mechanisms remains elusive. Herein, synchrotron in line phase contrast X ray tomography was employed to investigate the morphological evolution of electrochemically deposited dissolved LmSs nondestructively. We present a 3D characterization of electrochemically stripped Li electrodes with regard to electrochemically plated LmSs. We clarify fundamentally the origin of the porous lithium interface growing into Li electrodes. Moreover, cleavage of the separator caused by growing LmS was experimentally observed and visualized in 3D. Our systematic investigation provides fundamental insights into LmS evolution and enables us to understand the evolution mechanisms in Li electrodes more profoundl

Advances in the Surface Passivation of Silicon Solar Cells

AbstractThe surface passivation properties of aluminium oxide (Al2O3) on crystalline Si are compared with the traditional passivation system of silicon nitride (SiNx). It is shown that Al2O3 has fundamental advantages over SiNx when applied to the rear of p-type silicon solar cells as well as to the p+ emitter of n-type silicon solar cells. Special emphasis is paid to the transfer of Al2O3 into industrial solar cell production. We compare different Al2O3 deposition techniques suitable for mass production such as ultrafast spatial atomic layer deposition, inline plasma-enhanced chemical vapour deposition and reactive sputtering. Finally, we review the most recent cell results with Al2O3 passivation and give a brief outlook on the future prospects of Al2O3 in silicon solar cell production

Surface passivation of silicon solar cells using industrially relevant Al2O3 deposition techniques

The next generation of industrial silicon solar cells aims at efficiencies of 20% and above. To achieve this goal using ever-thinner silicon wafers, a highly effective surface passivation of the cell front and rear is required. In the past, finding a suitable dielectric layer providing a high-quality rear passivation has been a major challenge. Aluminium oxide (Al2O3) grown by atomic layer deposition (ALD) has only recently turned out to be a nearly perfect candidate for such a dielectric. However, conventional ALD is limited to deposition rates well below 2nm/min, which is incompatible with industrial solar cell production. This paper assesses the passivation quality provided by three different industrially relevant techniques for the deposition of Al2O3 layers, namely high-rate spatial ALD, plasma-enhanced chemical vapour deposition (PECVD) and reactive sputtering

Early events of Bacillus anthracis germination identified by time-course quantitative proteomics

Germination of Bacillus anthracis spores involves rehydration of the spore interior and rapid degradation of several of the protective layers, including the spore coat. Here, we examine the temporal changes that occur during B. anthracis spore germination using an isobaric tagging system. Over the course of 17 min from the onset of germination, the levels of at least 19 spore proteins significantly decrease. Included are acid-soluble proteins, several known and predicted coat proteins, and proteins of unknown function. Over half of these proteins are small (less than 100 amino acids) and would have been undetectable by conventional gel-based analysis. We also identified 20 proteins, whose levels modestly increased at the later time points when metabolism has likely resumed. Taken together, our data show that isobaric labeling of complex mixtures is particularly effective for temporal studies. Furthermore, we describe a rigorous statistical approach to define relevant changes that takes into account the nature of data obtained from multidimensional protein identification technology coupled with the use of isobaric tags. This study provides an expanded list of the proteins that may be involved in germination of the B. anthracis spore and their relative levels during germination.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55849/1/5199_ftp.pd

Molecular Characterization of a Patient Presumed to Have Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is caused by the loss of RNA expression from an imprinted region on chromosome 15 that includes SNRPN, SNORD115, and SNORD116. Currently, there are no mouse models that faithfully reflect the human phenotype and investigations rely on human post-mortem material. During molecular characterization of tissue deposited in a public brain bank from a patient diagnosed with Prader-Willi syndrome, we found RNA expression from SNRPN, SNORD115, and SNORD116 which does not support a genetic diagnosis of Prader-Willi syndrome. The patient was a female, Caucasian nursing home resident with history of morbid obesity (BMI 56.3) and mental retardation. She died at age of 56 from pulmonary embolism. SNORD115 and SNORD116 are unexpectedly stable in post mortem tissue and can be used for post-mortem diagnosis. Molecular characterization of PWS tissue donors can confirm the diagnosis and identify those patients that have been misdiagnosed

Reproducibility of parallel preconditioned conjugate gradient in hybrid programming environments

[EN] The Preconditioned Conjugate Gradient method is often employed for the solution of linear systems of equations arising in numerical simulations of physical phenomena. While being widely used, the solver is also known for its lack of accuracy while computing the residual. In this article, we propose two algorithmic solutions that originate from the ExBLAS project to enhance the accuracy of the solver as well as to ensure its reproducibility in a hybrid MPI + OpenMP tasks programming environment. One is based on ExBLAS and preserves every bit of information until the final rounding, while the other relies upon floating-point expansions and, hence, expands the intermediate precision. Instead of converting the entire solver into its ExBLAS-related implementation, we identify those parts that violate reproducibility/non-associativity, secure them, and combine this with the sequential executions. These algorithmic strategies are reinforced with programmability suggestions to assure deterministic executions. Finally, we verify these approaches on two modern HPC systems: both versions deliver reproducible number of iterations, residuals, direct errors, and vector-solutions for the overhead of less than 37.7% on 768 cores.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research was partially supported by the European Union's Horizon 2020 research, innovation program under the Marie Sklodowska-Curie grant agreement via the Robust project No. 842528 as well as the Project HPC-EUROPA3 (INFRAIA-2016-1-730897), with the support of the H2020 EC RIA Programme; in particular, the author gratefully acknowledges the support of Vicenc comma Beltran and the computer resources and technical support provided by BSC. The researchers from Universitat Jaume I (UJI) and Universitat Polit ' ecnica de Valencia (UPV) were supported by MINECO project TIN2017-82972-R. Maria Barreda was also supported by the POSDOC-A/2017/11 project from the Universitat Jaume I.Iakymchuk, R.; Barreda Vayá, M.; Graillat, S.; Aliaga, JI.; Quintana Ortí, ES. (2020). Reproducibility of parallel preconditioned conjugate gradient in hybrid programming environments. International Journal of High Performance Computing Applications. 34(5):502-518. https://doi.org/10.1177/1094342020932650S502518345Aliaga, J. I., Barreda, M., Flegar, G., Bollhöfer, M., & Quintana-Ortí, E. S. (2017). Communication in task-parallel ILU-preconditioned CG solvers using MPI + OmpSs. Concurrency and Computation: Practice and Experience, 29(21), e4280. doi:10.1002/cpe.4280Bailey, D. H. (2013). 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Proceedings 15th IEEE Symposium on Computer Arithmetic. ARITH-15 2001. doi:10.1109/arith.2001.930115Hunold, S., & Carpen-Amarie, A. (2016). Reproducible MPI Benchmarking is Still Not as Easy as You Think. IEEE Transactions on Parallel and Distributed Systems, 27(12), 3617-3630. doi:10.1109/tpds.2016.2539167IEEE Computer Society (2008) IEEE Standard for Floating-Point Arithmetic. Piscataway: IEEE Standard, pp. 754–2008.Kulisch, U., & Snyder, V. (2010). The exact dot product as basic tool for long interval arithmetic. Computing, 91(3), 307-313. doi:10.1007/s00607-010-0127-7Kulisch, U. (2013). Computer Arithmetic and Validity. doi:10.1515/9783110301793Lawson, C. L., Hanson, R. J., Kincaid, D. R., & Krogh, F. T. (1979). Basic Linear Algebra Subprograms for Fortran Usage. ACM Transactions on Mathematical Software, 5(3), 308-323. doi:10.1145/355841.355847Lutz, D. R., & Hinds, C. N. (2017). High-Precision Anchored Accumulators for Reproducible Floating-Point Summation. 2017 IEEE 24th Symposium on Computer Arithmetic (ARITH). doi:10.1109/arith.2017.20Mukunoki, D., Ogita, T., & Ozaki, K. (2020). Reproducible BLAS Routines with Tunable Accuracy Using Ozaki Scheme for Many-Core Architectures. Lecture Notes in Computer Science, 516-527. doi:10.1007/978-3-030-43229-4_44Nguyen, H. D., & Demmel, J. (2015). Reproducible Tall-Skinny QR. 2015 IEEE 22nd Symposium on Computer Arithmetic. doi:10.1109/arith.2015.28Ogita, T., Rump, S. M., & Oishi, S. (2005). Accurate Sum and Dot Product. SIAM Journal on Scientific Computing, 26(6), 1955-1988. doi:10.1137/030601818Ozaki, K., Ogita, T., Oishi, S., & Rump, S. M. (2011). Error-free transformations of matrix multiplication by using fast routines of matrix multiplication and its applications. Numerical Algorithms, 59(1), 95-118. doi:10.1007/s11075-011-9478-1Priest, D. M. (s. f.). Algorithms for arbitrary precision floating point arithmetic. [1991] Proceedings 10th IEEE Symposium on Computer Arithmetic. doi:10.1109/arith.1991.145549Rump, S. M., Ogita, T., & Oishi, S. (2008). Accurate Floating-Point Summation Part I: Faithful Rounding. SIAM Journal on Scientific Computing, 31(1), 189-224. doi:10.1137/050645671Rump, S. M., Ogita, T., & Oishi, S. (2009). Accurate Floating-Point Summation Part II: Sign, K-Fold Faithful and Rounding to Nearest. SIAM Journal on Scientific Computing, 31(2), 1269-1302. doi:10.1137/07068816xRump, S. M., Ogita, T., & Oishi, S. (2010). Fast high precision summation. Nonlinear Theory and Its Applications, IEICE, 1(1), 2-24. doi:10.1587/nolta.1.2Saad, Y. (2003). Iterative Methods for Sparse Linear Systems. doi:10.1137/1.9780898718003Wiesenberger, M., Einkemmer, L., Held, M., Gutierrez-Milla, A., Sáez, X., & Iakymchuk, R. (2019). Reproducibility, accuracy and performance of the Feltor code and library on parallel computer architectures. 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Improving MCS Enumeration via Caching

Enumeration of minimal correction sets (MCSes) of conjunctive normal form formulas is a central and highly intractable problem in infeasibility analysis of constraint systems. Often complete enumeration of MCSes is impossible due to both high computational cost and worst-case exponential number of MCSes. In such cases partial enumeration is sought for, finding applications in various domains, including axiom pinpointing in description logics among others. In this work we propose caching as a means of further improving the practical efficiency of current MCS enumeration approaches, and show the potential of caching via an empirical evaluation.Peer reviewe