1,393 research outputs found
SynKB: Semantic Search for Synthetic Procedures
In this paper we present SynKB, an open-source, automatically extracted
knowledge base of chemical synthesis protocols. Similar to proprietary
chemistry databases such as Reaxsys, SynKB allows chemists to retrieve
structured knowledge about synthetic procedures. By taking advantage of recent
advances in natural language processing for procedural texts, SynKB supports
more flexible queries about reaction conditions, and thus has the potential to
help chemists search the literature for conditions used in relevant reactions
as they design new synthetic routes. Using customized Transformer models to
automatically extract information from 6 million synthesis procedures described
in U.S. and EU patents, we show that for many queries, SynKB has higher recall
than Reaxsys, while maintaining high precision. We plan to make SynKB available
as an open-source tool; in contrast, proprietary chemistry databases require
costly subscriptions.Comment: Accepted to EMNLP 2022 Demo trac
Pengaruh Kinerja Hutang Terhadap Nilai Perusahaan Pada Perusahaan Pertambangan Batubara Yang Terdaftar Di BEI Periode 2010-2013
The primary goal of the company is to maximize firm value. Firm value is investor perceptionof the company\u27s success rate, it is often associated with stock prices. This research aim to examine the effect of leverage towards the value of the company in the coal mining companies which listed on the Indonesia Stock Exchange with periods 2010-2011. The hypothesis was leverage has negative effect on firm value. This research uses secondary data, of the coal mining companies which listed on BEI with periods 2010-2013. Research sample of 15 companies, where the method used is purposive sampling is a sampling method that takes an object with the specified criteria. Leverage are measured using Debt to Equity Ratio (DER) and Debt to Asset Ratio (DAR). Meanwhile, firm value is measured using Price Earning Ratio (PER). Analysis of the data used to analyze the factor that affect firm value is simple linier regression analysis and hypothesis test used the t-statistic for testing the partial regression coeffiecient at level of significant 5%. The results of this research finds leverage (DER) has negative significant effect on firm value (PER) with predictive ability is 6,8% and it shown by R square, and leverage (DAR) has negative significant effect on firm value (PER) with predictive ability is 7,2% and it shown by R square
Effect of bevelled silo outlet in the flow rate during discharge
We investigate the effect of a bevelled (or slanted) outlet on the discharge rate of mono-sized spheres from a quasi-two-dimensional silo, using the discrete element method. In contrast to hopper discharges, where the bevelling is across the entire base of the container, we study a bevelled opening that is significantly smaller than the silo width and in which the slanting is limited to half a sphere diameter at the boundary of the outlet. We show that the bevelling increases the flow rate comparably to the inclination in hopper walls. Using Beverloo's model, we relate this increase in rate to what we define as the ‘effective opening’ of the silo and analyse the velocity profiles associated with the discharges. We show that different openings, having effectively the same discharge rates, give rise to distinctly different internal dynamics in the silo. These results have the potential to aid industrial processes by fine-tuning and improving control of silo discharges, with a minimal impact on silo design, thus significantly reducing production and handling costs.Fil: Gago, Paula Alejandra. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Imperial College London; Reino UnidoFil: Madrid, Marcos Andres. Universidad Tecnológica Nacional; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Boettcher, Stefan. University of Emory; Estados UnidosFil: Blumenfeld, Raphael. Imperial College London; Reino UnidoFil: King, Peter. Imperial College London; Reino Unid
Resolving the Circumstellar Disk Around the Massive Protostar Driving the HH 80-81 Jet
We present new high-angular resolution observations toward the driving source
of the HH 80-81 jet (IRAS 18162-2048). Continuum emission was observed with the
Very Large Array at 7 mm and 1.3 cm, and with the Submillimeter Array at 860
microns, with angular resolutions of ~0"1 and ~0"8 respectively. Submillimeter
observations of the sulfur oxide (SO) molecule are reported as well. At 1.3 cm
the emission traces the well-known radio jet, while at 7 mm the continuum
morphology is quadrupolar and seems to be produced by a combination of
free-free and dust emission. An elongated structure perpendicular to the jet
remains in the 7 mm image after subtraction of the free-free contribution. This
structure is interpreted as a compact accretion disk of ~200 AU radius. Our
interpretation is favored by the presence of rotation in our SO observations
observed at larger scales. The observations presented here add to the small
list of cases where the hundred-AU scale emission from a circumstellar disk
around a massive protostar has been resolved.Comment: Accepted for publication in ApJ Letter
Endothelial adhesion receptors are recruited to adherent leukocytes by inclusion in preformed tetraspanin nanoplatforms
VCAM-1 and ICAM-1, receptors for leukocyte integrins, are recruited to cell–cell contact sites on the apical membrane of activated endothelial cells. In this study, we show that this recruitment is independent of ligand engagement, actin cytoskeleton anchorage, and heterodimer formation. Instead, VCAM-1 and ICAM-1 are recruited by inclusion within specialized preformed tetraspanin-enriched microdomains, which act as endothelial adhesive platforms (EAPs). Using advanced analytical fluorescence techniques, we have characterized the diffusion properties at the single-molecule level, nanoscale organization, and specific intradomain molecular interactions of EAPs in living primary endothelial cells. This study provides compelling evidence for the existence of EAPs as physical entities at the plasma membrane, distinct from lipid rafts. Scanning electron microscopy of immunogold-labeled samples treated with a specific tetraspanin-blocking peptide identify nanoclustering of VCAM-1 and ICAM-1 within EAPs as a novel mechanism for supramolecular organization that regulates the leukocyte integrin–binding capacity of both endothelial receptors during extravasation
Simulated observations of star formation regions: infrared evolution of globally collapsing clouds
The direct comparison between hydrodynamical simulations and observations is
needed to improve the physics included in the former and test biases in the
latter. Post-processing radiative transfer and synthetic observations are now
the standard way to do this. We report on the first application of the
\texttt{SKIRT} radiative transfer code to simulations of a star-forming cloud.
The synthetic observations are then analyzed following traditional
observational workflows. We find that in the early stages of the simulation,
stellar radiation is inefficient in heating dust to the temperatures observed
in Galactic clouds, thus the addition of an interstellar radiation field is
necessary. The spectral energy distribution of the cloud settles rather quickly
after Myr of evolution from the onset of star formation, but its
morphology continues to evolve for Myr due to the expansion of
\textsc{Hii} regions and the respective creation of cavities, filaments, and
ridges. Modeling synthetic \textit{Herschel} fluxes with 1- or 2-component
modified black bodies underestimates total dust masses by a factor of .
Spatially-resolved fitting recovers up to about of the intrinsic value.
This ``missing mass'' is located in a very cold dust component with
temperatures below K, which does not contribute appreciably to the
far-infrared flux. This effect could bias real observations if such dust exists
in large amounts. Finally, we tested observational calibrations of the SFR
based on infrared fluxes and concluded that they are in agreement when compared
to the intrinsic SFR of the simulation averaged over Myr
Effect of bevelled silo outlet in the flow rate during discharge
We investigate the effect of a bevelled (or slanted) outlet on the discharge rate of mono-sized spheres from a quasi-two-dimensional silo, using the discrete element method. In contrast to hopper discharges, where the bevelling is across the entire base of the container, we study a bevelled opening that is significantly smaller than the silo width and in which the slanting is limited to half a sphere diameter at the boundary of the outlet. We show that the bevelling increases the flow rate comparably to the inclination in hopper walls.
Using Beverloo’s model, we relate this increase in rate to what we define as the ‘effective opening’ of the silo and analyse the velocity profiles associated with the discharges. We show that different openings, having effectively the same discharge rates, give rise to distinctly different internal dynamics in the silo. These results have the potential to aid industrial processes by fine-tuning and improving control of silo discharges, with a minimal impact on silo design, thus significantly reducing production and handling costs.Instituto de FÃsica de LÃquidos y Sistemas Biológico
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