178 research outputs found
Hybrid Model Approaches to Predict Multiscale and Multiphysics Coastal Hydrodynamic and Sediment Transport Processes
Past production constrains current energy demands: persistent scaling in global energy consumption and implications for climate change mitigation
Climate change has become intertwined with the global economy. Here, we
describe the importance of inertia to continued growth in energy consumption.
Drawing from thermodynamic arguments, and using 38 years of available
statistics between 1980 to 2017, we find a persistent time-independent scaling
between the historical time integral of world inflation-adjusted economic
production , or , and
current rates of world primary energy consumption , such that
Gigawatts per trillion 2010 US dollars.
This empirical result implies that population expansion is a symptom rather
than a cause of the current exponential rise in and carbon dioxide
emissions , and that it is past innovation of economic production efficiency
that has been the primary driver of growth, at predicted rates
that agree well with data. Options for stabilizing are then limited to
rapid decarbonization of through sustained implementation of over
one Gigawatt of renewable or nuclear power capacity per day. Alternatively,
assuming continued reliance on fossil fuels, civilization could shift to a
steady-state economy that devotes economic production exclusively to
maintenance rather than expansion. If this were instituted immediately,
continual energy consumption would still be required, so atmospheric carbon
dioxide concentrations would not balance natural sinks until concentrations
exceeded 500 ppmv, and double pre-industrial levels if the steady-state was
attained by 2030
Estimates of economic and environmental damages from tipping points cannot be reconciled with the scientific literature
Peer reviewe
Can we accurately forecast non-elective bed occupancy and admissions in the NHS?:A time-series MSARIMA analysis of longitudinal data from an NHS Trust
OBJECTIVES: The main objective of the study was to develop more accurate and precise short-term forecasting models for admissions and bed occupancy for an NHS Trust located in Bristol, England. Subforecasts for the medical and surgical specialties, and for different lengths of stay were realised DESIGN: Autoregressive integrated moving average models were specified on a training dataset of daily count data, then tested on a 6-week forecast horizon. Explanatory variables were included in the models: day of the week, holiday days, lagged temperature and precipitation. SETTING: A secondary care hospital in an NHS Trust in South West England. PARTICIPANTS: Hospital admissions between September 2016 and March 2020, comprising 1291 days. PRIMARY AND SECONDARY OUTCOME MEASURES: The accuracy of the forecasts was assessed through standard measures, as well as compared with the actual data using accuracy thresholds of 10% and 20% of the mean number of admissions or occupied beds. RESULTS: The overall Autoregressive Integrated Moving Average (ARIMA) admissions forecast was compared with the Trust’s forecast, and found to be more accurate, namely, being closer to the actual value 95.6% of the time. Furthermore, it was more precise than the Trust’s. The subforecasts, as well as those for bed occupancy, tended to be less accurate compared with the overall forecasts. All of the explanatory variables improved the forecasts. CONCLUSIONS: ARIMA models can forecast non-elective admissions in an NHS Trust accurately on a 6-week horizon, which is an improvement on the current predictive modelling in the Trust. These models can be readily applied to other contexts, improving patient flow
Building the Holocene clinothem in the Gulf of Papua: An ocean circulation study
This paper investigates the role that tidal and wind-driven flows and buoyant river plumes play in the development of the Holocene clinothem in the Gulf of Papua. Time series data from bottom tripods and a mooring were obtained at four locations near the mouth of the Fly River during portions of 2003 and 2004. Flows in the Gulf of Papua during calendar year 2003 were hindcast every 3 h using the Navy Coastal Ocean Model (NCOM) with boundary conditions from the Navy Atmospheric Prediction System, the east Asian seas implementation of NCOM, and the OTIS Tidal Inversion System. Results show that tidal flows on the modern clinoform are strong and are landward and seaward directed. Peak spring tidal velocities can provide the shear stresses necessary to keep sediment up to sand size in motion as the wind-driven and baroclinic currents distribute it from the river mouths across and along the shelf in two circulation states. During the monsoon season, the clinoform topset is swept by a seaward surface flow and landward bottom flow, reflecting river plumes and coastal upwelling. Seaward, this structure evolves into a SW directed surface current over the clinothem foreset with accompanying landward directed near-bed currents that trend obliquely up the foreset to the WSW over much of the clinothem. During the trade wind season, the inner and outer topset are swept by NE directed, contour-parallel surface currents, underneath which lie obliquely landward near-bed currents. These modeled flows and complex gyres in shallow water coupled with wave- and current-supported gravity flows or river floods can explain the form, internal clinoform shapes, and mineralogy of the modern Gulf of Papua clinothem
Timescales, mechanisms, and controls of incisional avulsions in floodplain wetlands: insights from the Tshwane River, semiarid South Africa
Phylogenetic classification of Escherichia coli O157:H7 strains of human and bovine origin using a novel set of nucleotide polymorphisms
Novel SNPs from human and bovine O157:H7 E. coli isolates are mapped, revealing that the majority of human disease is caused by a bovine subset of this strain
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Mixed hierarchical local structure in a disordered metal–organic framework
Abstract: Amorphous metal–organic frameworks (MOFs) are an emerging class of materials. However, their structural characterisation represents a significant challenge. Fe-BTC, and the commercial equivalent Basolite® F300, are MOFs with incredibly diverse catalytic ability, yet their disordered structures remain poorly understood. Here, we use advanced electron microscopy to identify a nanocomposite structure of Fe-BTC where nanocrystalline domains are embedded within an amorphous matrix, whilst synchrotron total scattering measurements reveal the extent of local atomic order within Fe-BTC. We use a polymerisation-based algorithm to generate an atomistic structure for Fe-BTC, the first example of this methodology applied to the amorphous MOF field outside the well-studied zeolitic imidazolate framework family. This demonstrates the applicability of this computational approach towards the modelling of other amorphous MOF systems with potential generality towards all MOF chemistries and connectivities. We find that the structures of Fe-BTC and Basolite® F300 can be represented by models containing a mixture of short- and medium-range order with a greater proportion of medium-range order in Basolite® F300 than in Fe-BTC. We conclude by discussing how our approach may allow for high-throughput computational discovery of functional, amorphous MOFs
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