Uncertainty Quantification Visualization Tool to Simulate Porous Lithium-Ion Batteries

To maintain people’s fast-paced lifestyles, a more powerful and reliable rechargeable battery is critical. During the manufacturing process, electrode parameters such as cathode thickness, the porosity of the positive electrode and radius of negative active materials are subject to uncertainty. Such uncertainty may have a dramatic impact on the performance of the battery. To optimize its performance, it is critical to quantify uncertainty due to variation in electrode parameters and measure the response of the system through multiscale computer simulation. To achieve this goal, a porous lithium-ion battery uncertainty quantification and visualization tool has been created. This tool consists of three components: 1) a generator of uncertainty input; 2) an electrochemical system simulator; 3) a statistical analysis and visualization module. This project focuses on the first and the third components. First, the uncertainty input generator provides the option of selecting one of two statistical models for the input parameter distributions: Gaussian and lognormal. For Gaussian and lognormal distributions, sample points and weights are generated based on Gauss-Hermite quadrature formula. Each module provides a GUI, built using an open source, class-oriented environment, the Virtual Kinetics of Materials Lab [1]. Ensemble simulations are performed using the electrochemical system simulator that in turn uses the data distributions obtained from the uncertainty input generator. In the statistics analysis and visualization component, the simulation results are quantified graphically through error bar plots that visualize the impact of the uncertainties that were introduced into the system. The variation of power and energy densities as a function of current density of the battery electrode is presented, enabling the user to visualize the uncertainty propagation from the three electrode uncertainty inputs and its impact on the battery performance. [1] Alex Bartol; R. Edwin García; David R. Ely; Jon Guyer (2015), The Virtual Kinetics of Materials Laboratory, https://nanohub.org/resources/vkmllive. (DOI: 10.4231/D3B853J85)

Interactive Computer Aided Design of Electrochemical Systems

The most popular and widely used rechargeable battery numerical model, the dualfoil, was developed in fortran by John Newman and coworkers1-3, and enables the user to describe the time-dependent electrochemical transport of lithium and charge, through the application of concentrated solution theory in porous media. Such a model has enabled the design of many advanced lithium-ion batteries for hybrid and plug-in electric vehicles that can operate under high current densities. Historically, however, the dualfoil and other subsequently derived models are cumbersome and unwieldy when used, and offer limited flexibility regarding parameter variability, integration into more sophisticated numerical descriptions, coupling to multiscale formulations, or the simple visualization of generated data. The nature of dualfoil makes it difficult to use, and it does not allow for systematic parametric analyses, or direct integration into high performing, multiscale numerical frameworks. This work introduces a proof of concept for a flexible application programming interface, dualfoil.py, that enables hierarchical control over the dualfoil legacy code and visualization modules, and provides the user with the ability to rapidly set up complex, multiscale simulations. Furthermore, the program features a GUI-mode for single-run simulations, and a powerful text-mode for setting up large simulation queues. By making use of the object oriented nature of Python, dualfoil.py allows the user to generate, organize, and visualize the electrochemical responses from the battery. Cell potential, anode and cathode active material utilization, and power/energy densities of multiple battery scenarios are modeled and presented, demonstrating the iterative capability of dualfoil.py. This versatile program allows for users of any skill level to achieve robust results in a control oriented and rapidly deployable manner

Ultraluminous infrared galaxies: mergers of sub-L* galaxies?

A sample of 27 low-redshift, mostly cool, ultraluminous infrared galaxies (ULIRGs) has been imaged at 1.6 μm with the Hubble Space Telescope (HST) Near-Infrared Camera and Multi-Object Spectrometer (NICMOS). The majority (67%) of the sample's galaxies are multiple-nucleus galaxies with projected separations of up to 17 kpc, and the rest of the sample (33%) are single-nucleus galaxies, as determined by the NICMOS angular resolution limit. The average observed, integrated (host+nucleus) H magnitude of our HST H sample ULIRGs is -24.3, slightly above that of an L* galaxy (MH = -24.2), and 52% of the sample's galaxies have sub-L* luminosities. The ULIRGs in the HST H sample are not generated as a result of the merging of two luminous (i.e., ≥L*) spiral galaxies. Instead, the interactions and mergers occur in general between two, or in some cases more, less massive sub-L* (0.3-0.5L*) galaxies. Only one out of the 49 nuclei identified in the entire HST H sample has the properties of a bright quasar-like nucleus. On average, the brightest nuclei in the HST H sample galaxies (i.e., cool ULIRGs) are 1.2 mag fainter than warm ULIRGs and low-luminosity Bright Quasar Survey quasars (BQS QSOs) and 2.6 mag fainter than high-luminosity BQS QSOs. Since the progenitor galaxies involved in the merger are sub-L* galaxies, the mass of the central black hole in these ULIRGs would be only about (1-2) × 107 M☉, if the bulge-to-black hole mass ratio of nearby galaxies holds for ULIRGs. The estimated mass of the central black hole is similar to that of nearby Seyfert 2 galaxies but at least 1 order of magnitude lower than the massive black holes thought to be located at the center of high-luminosity QSOs. Massive nuclear starbursts with constant star formation rates of 10-40 M☉ yr-1 could contribute significantly to the nuclear H-band flux and are consistent with the observed nuclear H-band magnitudes of the ULIRGs in the HST H sample. An evolutionary merging scenario is proposed for the generation of the different types of ULIRGs and QSOs on the basis of the masses of the progenitors involved in the merging process. According to this scenario, cool ULIRGs would be the end product of the merging of two or more low-mass (0.3L*-0.5L*) disk galaxies. Warm ULIRGs and low-luminosity QSOs would be generated by a merger involving intermediate-mass (0.5 L*) disk galaxies. Under this scenario, warm ULIRGs could still be the dust-enshrouded phases of UV-bright low-luminosity QSOs, but cool ULIRGs, which are most ULIRGs, would not evolve into QSOs

Sepsis in obstetrics and the role of the anaesthetist

ABSTRACT Sepsis in pregnancy and the puerperium remains a significant cause of maternal mortality and morbidity worldwide. Major morbidity arising as a result of obstetric sepsis includes fetal demise, organ failure, chronic pelvic inflammatory disease, chronic pelvic pain, bilateral tubal occlusion and infertility. Early recognition and timely response are key to ensuring good outcome. This review examines the clinical problem of sepsis in obstetrics and the role of the anaesthetist in the management of this condition

Conserved stromal-immune cell circuits secure B cell homeostasis and function

B cell zone reticular cells (BRCs) form stable microenvironments that direct efficient humoral immunity with B cell priming and memory maintenance being orchestrated across lymphoid organs. However, a comprehensive understanding of systemic humoral immunity is hampered by the lack of knowledge of global BRC sustenance, function and major pathways controlling BRC-immune cell interactions. Here we dissected the BRC landscape and immune cell interactome in human and murine lymphoid organs. In addition to the major BRC subsets underpinning the follicle, including follicular dendritic cells, PI16$^{+}$ RCs were present across organs and species. As well as BRC-produced niche factors, immune cell-driven BRC differentiation and activation programs governed the convergence of shared BRC subsets, overwriting tissue-specific gene signatures. Our data reveal that a canonical set of immune cell-provided cues enforce bidirectional signaling programs that sustain functional BRC niches across lymphoid organs and species, thereby securing efficient humoral immunity

Ultraluminous Infrared Galaxies: Atlas of Near-Infrared Images

A sample of 27 ultraluminous infrared galaxy (ULIRG) systems has been imaged at 1.6 microns using the HST Near Infrared Camera and Multi-Object Spectrometer (NICMOS). These ULIRGs are from a larger sample also imaged with HST in the I-band. Images and catalog information for the NICMOS subsample, as well as brief morphological descriptions of each system are presented. Inspection of the infrared images and a comparison with optical images of these systems shows that at least 85% are obviously composed of two or more galaxies involved in a close interaction or merger event, with as many as 93% showing some signs of interaction history. Approximately 37% of the systems show either spectroscopic or morphological characteristics of an active galactic nucleus (AGN). The infrared morphologies of these systems are generally less complicated or disturbed than their optical morphologies, indicating that some of the small-scale features seen in optical images are likely due to complicated patterns of dust obscuration, as well as widely distributed star formation activity. In some systems the high-resolution HST infrared images have revealed nuclear remnants that are obscured or unidentified in ground-based imaging, which has led to changes in previously determined interaction stage classifications or system content. In general, however, the NICMOS images support previous conclusions from previous HST optical imaging.Comment: To appear in ApJSupp; 9 embedded figures; Complete ps copy with higher resolution figures available at http://www.stsci.edu/~bushous

Vitellogenin Underwent Subfunctionalization to Acquire Caste and Behavioral Specific Expression in the Harvester Ant Pogonomyrmex barbatus

PMCID: PMC3744404This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication