Measurement of Electric Conductivity of Hot Gas in a SF6-circuit Breaker Interrupting Fault Currents

The realization of a new measurement method to determine electric conductivity of hot SF6-gas during interruption fault currents in an original self-blast circuit breaker is presented. The method is based on evaluation of phase shift between sinusoidal kHz-high voltage and current, applied on a sensor. This needs a kHz-resonance voltage generator and adapted sensors as a part of an electromagnetic shielded measurement system to determine time dependent electric conductivity with high resolution

Prenatal Lead Exposure Risk Assessment by Vermont Maternity Care Providers

Introduction. One percent of women of childbearing age in the U.S. have blood lead levels ≥ 5 ug/dL, which are associated with maternal hypertension during pregnancy, neural tube and cardiac defects in infants, low birth weight, prematurity, and spontaneous abortion. It is unknown whether obstetrics providers in Vermont are screening their pregnant patients for lead levels and educating them on lead exposure risks. Objective. To gain an understanding of current lead screening practices in Vermont and issue recommendations for disseminating lead screening information. Methods. We developed and e-mailed a survey to practicing OB/GYN physicians, maternity care focused family medicine physicians, nurse midwives, and professional midwives. The survey assessed current screening practices for lead exposure in their pregnant patients, interest in receiving statewide guidelines, and guideline dissemination preferences. Results. Of the 41 respondents, 12% currently conduct risk assessments for lead exposure with all of their pregnant patients. Fifty four percent of maternity providers give all of their patients educational materials about lead exposure and risk of toxicity. Seventy one percent of maternity providers think that having guidelines provided by the Vermont Department of Health would encourage them to begin or continue lead exposure screening. The two preferred methods of communicating guidelines to physicians were grand rounds and email whereas non-physician providers preferred email and webinar. Discussion. The majority of pregnant patients in Vermont are not properly assessed or educated about lead risks. However, there is interest in having statewide standardized lead risk assessment guidelines, with dissemination preferences differing by provider type.https://scholarworks.uvm.edu/comphp_gallery/1248/thumbnail.jp

Solving the Klein-Gordon equation using Fourier spectral methods: A benchmark test for computer performance

The cubic Klein-Gordon equation is a simple but non-trivial partial differential equation whose numerical solution has the main building blocks required for the solution of many other partial differential equations. In this study, the library 2DECOMP&FFT is used in a Fourier spectral scheme to solve the Klein-Gordon equation and strong scaling of the code is examined on thirteen different machines for a problem size of 512^3. The results are useful in assessing likely performance of other parallel fast Fourier transform based programs for solving partial differential equations. The problem is chosen to be large enough to solve on a workstation, yet also of interest to solve quickly on a supercomputer, in particular for parametric studies. Unlike other high performance computing benchmarks, for this problem size, the time to solution will not be improved by simply building a bigger supercomputer.Comment: 10 page

Influence of Magnetism on Phonons in CaFe2As2 Via Inelastic X-ray Scattering

In the iron pnictides, the strong sensitivity of the iron magnetic moment to the arsenic position suggests a significant relationship between phonons and magnetism. We measured the phonon dispersion of several branches in the high temperature tetragonal phase of CaFe2As2 using inelastic x-ray scattering on single-crystal samples. These measurements were compared to ab initio calculations of the phonons. Spin polarized calculations imposing the antiferromagnetic order present in the low temperature orthorhombic phase dramatically improve agreement between theory and experiment. This is discussed in terms of the strong antiferromagnetic correlations that are known to persist in the tetragonal phase.Comment: 4 pages, 3 figures; added additional information and references about spin fluctuation

Strongly Anisotropic Magnesiowüstite in Earth's Lower Mantle

The juxtaposition of a liquid iron‐dominant alloy against a mixture of silicate and oxide minerals at Earth's core‐mantle boundary is associated with a wide range of complex seismological features. One category of observed structures is ultralow‐velocity zones, which are thought to correspond to either aggregates of partially molten material or solid, iron‐enriched assemblages. We measured the phonon dispersion relations of (Mg,Fe) O magnesiowüstite containing 76 mol % FeO, a candidate ultralow‐velocity zone phase, at high pressures using high‐energy resolution inelastic X‐ray scattering. From these measurements, we find that magnesiowüstite becomes strongly elastically anisotropic with increasing pressure, potentially contributing to a significant proportion of seismic anisotropy detected near the base of the mantle

Revealing mechanisms of infectious disease spread through empirical contact networks

The spread of pathogens fundamentally depends on the underlying contacts between individuals. Modeling the dynamics of infectious disease spread through contact networks, however, can be challenging due to limited knowledge of how an infectious disease spreads and its transmission rate. We developed a novel statistical tool, INoDS (Identifying contact Networks of infectious Disease Spread) that estimates the transmission rate of an infectious disease outbreak, establishes epidemiological relevance of a contact network in explaining the observed pattern of infectious disease spread and enables model comparison between different contact network hypotheses. We show that our tool is robust to incomplete data and can be easily applied to datasets where infection timings of individuals are unknown. We tested the reliability of INoDS using simulation experiments of disease spread on a synthetic contact network and find that it is robust to incomplete data and is reliable under different settings of network dynamics and disease contagiousness compared with previous approaches. We demonstrate the applicability of our method in two host-pathogen systems: Crithidia bombi in bumblebee colonies and Salmonella in wild Australian sleepy lizard populations. INoDS thus provides a novel and reliable statistical tool for identifying transmission pathways of infectious disease spread. In addition, application of INoDS extends to understanding the spread of novel or emerging infectious disease, an alternative approach to laboratory transmission experiments, and overcoming common data-collection constraints.Pratha Sah, Michael Otterstatter, Stephan T. Leu, Sivan Leviyang, Shweta Bansa

A constrained Potts antiferromagnet model with an interface representation

We define a four-state Potts model ensemble on the square lattice, with the constraints that neighboring spins must have different values, and that no plaquette may contain all four states. The spin configurations may be mapped into those of a 2-dimensional interface in a 2+5 dimensional space. If this interface is in a Gaussian rough phase (as is the case for most other models with such a mapping), then the spin correlations are critical and their exponents can be related to the stiffness governing the interface fluctuations. Results of our Monte Carlo simulations show height fluctuations with an anomalous dependence on wavevector, intermediate between the behaviors expected in a rough phase and in a smooth phase; we argue that the smooth phase (which would imply long-range spin order) is the best interpretation.Comment: 61 pages, LaTeX. Submitted to J. Phys.

Inelastic x-ray study of phonon broadening and charge-density wave formation in ortho-II-ordered YBa₂Cu₃O_6.54

Inelastic x-ray scattering is used to investigate charge-density wave (CDW) formation and the low-energy lattice dynamics of the underdoped high-temperature superconductor ortho-II YBa2Cu3O6.54. We find that, for a temperature similar to 1/3 of the CDW onset temperature (approximate to 155 K), the CDW order is static within the resolution of the experiment, that is the inverse lifetime is less than 0.3 meV. In the same temperature region, low-energy phonons near the ordering wave vector of the CDW show large increases in their linewidths. This contrasts with the usual behavior in CDW systems where the phonon anomalies are strongest near the CDW onset temperature

Modeling of Cloud-Based Digital Twins for Smart Manufacturing with MT Connect

The common modeling of digital twins uses an information model to describe the physical machines. The integration of digital twins into productive cyber-physical cloud manufacturing (CPCM) systems imposes strong demands such as reducing overhead and saving resources. In this paper, we develop and investigate a new method for building cloud-based digital twins (CBDT), which can be adapted to the CPCM platform. Our method helps reduce computing resources in the information processing center for efficient interactions between human users and physical machines. We introduce a knowledge resource center (KRC) built on a cloud server for information intensive applications. An information model for one type of 3D printers is designed and integrated into the core of the KRC as a shared resource. Several experiments are conducted and the results show that the CBDT has an excellent performance compared to existing methods