Virtual Electrode Design for Lithium-Ion Battery Cathodes

Microstructural characteristics of lithium‐ion battery cathodes determine their performance. Thus, modern simulation tools are increasingly important for the custom design of multiphase cathodes. This work presents a new method for generating virtual, yet realistic cathode microstructures. A precondition is a 3D template of a commercial cathode, reconstructed via focused ion beam/scanning electron microscopy (FIB/SEM) tomography and appropriate algorithms. The characteristically shaped micrometer‐sized active material (AM) particles and agglomerates of nano‐sized carbon‐binder (CB) particles are individually extracted from the voxel‐based templates. Thereby, a library of roughly 1100 AM particles and 20 CB agglomerates is created. Next, a virtual cathode microstructure is predefined, and representative sets of AM particles and CB agglomerates are built. The following re‐assembly of AM particles within a predefined volume box works using dropping and rolling algorithms. Thereby, one can generate cathodes with specified characteristics, such as the volume fraction of AM, CB and pore space, particle‐size distributions, and gradients thereof. Naturally, such a virtual twin is a promising starting point for physics‐based electrochemical performance models. The workflow from the commercial cathode microstructure through to a full virtual twin will be explained and assessed for a blend cathode made of the two AMs, LiNiCoAlO$_{2}$ (NCA) and LiCoO$_{2}$ (LCO)

Conflicting estimates of natural geologic methane emissions

Global bottom-up and top-down estimates of natural, geologic methane (CH4) emissions (average approximately 45 Tg yr–1) have recently been questioned by near-zero (approximately 1.6 Tg yr–1) estimates based on measurements of 14CH4 trapped in ice cores, which imply that current fossil fuel industries' CH4 emissions are underestimated by 25%–40%. As we show here, such a global near-zero geologic CH4 emission estimate is incompatible with multiple independent, bottom-up emission estimates from individual natural geologic seepage areas, each of which is of the order of 0.1–3 Tg yr–1. Further research is urgently needed to resolve the conundrum before rejecting either method or associated emission estimates in global CH4 accounting

Looking Towards Curiosity's Canyon Path: a 4 km Sequence of Gully, Debris Deposits, and Fan/Deltas Which are Bordered by a Sloping Bedform-Capped Plain and Crossed by Lake Shorelines

The Curiosity Rover is headed towards layered outcrops that appear to be rich in phyllosilicates and sulphates with the expectation of an eventual ascent up Mt. Sharp. One likely will take the rover up a well-defined canyon. Inspection of CTX and HiRISE imagery and topography (5 m contour intervals) reveal a rich geomorphic sequence that may be encountered during the journey

Effort-reward imbalance and burnout among humanitarian aid workers

Objectives: This study examined stress-related working conditions – defined in terms of effort-reward imbalance (ERI) – and its association with burnout among a large, international sample of humanitarian aid workers. Methods: Descriptive statistics were applied on crosssectional survey data (N=1,980) to profile ERI and burnout and Pearson’s χ 2 tests used to characterize associated socio- and occupational-demographic factors. Associations between ERI and burnout were established using binary logistic regression to generate odds ratios and 95% confidence intervals adjusted for potential confounding variables. Results: For high emotional exhaustion, the prevalence rate was 36% for women and 27% for men; high depersonalisation, 9% and 10%; and low personal achievement, 47% and 31%. Intermediate and high ERI was associated with significantly increased odds of high emotional exhaustion, with mixed findings for depersonalisation and personal achievement. Conclusions: The ERI model was supported as a useful framework for investigating occupational correlates of burnout

Search for a 33.9 MeV/c^2 Neutral Particle in Pion Decay

The E815 (NuTeV) neutrino experiment has performed a search for a 33.9 MeV/c^2 weakly-interacting neutral particle produced in pion decay. Such a particle may be responsible for an anomaly in the timing distribution of neutrino interactions in the KARMEN experiment. E815 has searched for this particle's decays in an instrumented decay region; no evidence for this particle was found. The search is sensitive to pion branching ratios as low as 10^-13.Comment: 4 pages; 5 figure

Centimeter to Decimeter Size Spherical and Cylindrical Features in Gale Crater Sediments

The Curiosity rover traverse in Gale crater has explored a large series of sedimentary deposits in an ancient lake on Mars. Over the nine kilometers of traverse a recurrent observation has been southward-dipping sedimentary strata, from Shaler at the edge of Yellowknife Bay to the striated units near the Kimberley. Within the sedimentary strata cm- to decimeter- size hollow spheroidal objects and some apparent cylindrical objects have been observed. These features have not been seen by previous landed missions. The first of these were observed on sol 122 in the Gillespie Lake member at Yellowknife Bay. Additional hollow features were observed in the Point Lake outcrop in the same area. More recently a spherical and apparently hollow object, Winnipesaukee, was observed by ChemCam and Mastcam on sol 653. Here we describe the settings, morphology, and associated compositions, and we discuss possible origins of these objects

Near-infrared, mode-locked waveguide lasers with multi-GHz repetition rates

In this work, we discuss mode-locking results obtained with low-loss, ion-exchanged waveguide lasers. With Yb3+-doped phosphate glass waveguide lasers, a repetition rate of up to 15.2 GHz was achieved at a wavelength of 1047 nm with an average power of 27 mW and pulse duration of 811 fs. The gap between the waveguide and the SESAM introduced negative group velocity dispersion via the Gires Tournois Interferometer (GTI) effect which allowed the soliton mode-locking of the device. A novel quantum dot SESAM was used to mode-lock Er3+, Yb3+-doped phosphate glass waveguide lasers around 1500 nm. Picosecond pulses were achieved at a maximum repetition rate of 6.8 GHz and an average output power of 30 mW. The repetition rate was tuned by more than 1 MHz by varying the pump power

Adrenomedullin and tumour angiogenesis

The angiogenic activity of peptide adrenomedullin (AM) was first shown in 1998 . Since then, a number of reports have confirmed the ability of AM to induce the growth and migration of isolated vascular endothelial and smooth muscle cells in vitro and to promote angiogenesis in xenografted tumours in vivo. In addition, knockout murine models point to an essential role for AM in embryonic vasculogenesis and ischaemic revascularisation. AM expression is upregulated by hypoxia (a typical feature of solid tumours) and a potential role as a regulator of carcinogenesis and tumour progression has been proposed based on studies in vitro and in animal models. Nevertheless, translational research on AM, and in particular, confirmation of its importance in the vascularisation of human tumours has lagged behind. In this commentary, we review current progress and potential directions for future research into the role of AM in tumour angiogenesis

Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV

A search for new physics is presented based on an event signature of at least three jets accompanied by large missing transverse momentum, using a data sample corresponding to an integrated luminosity of 36 inverse picobarns collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector at the LHC. No excess of events is observed above the expected standard model backgrounds, which are all estimated from the data. Exclusion limits are presented for the constrained minimal supersymmetric extension of the standard model. Cross section limits are also presented using simplified models with new particles decaying to an undetected particle and one or two jets