47,268 research outputs found
Skeletal P/Ca tracks upwelling in Gulf of Panama coral: Evidence for a new seawater phosphate proxy
Get PDFThe supply of limiting nutrients to the low latitude ocean is controlled by physical processes linked to climate variations, but methods for reconstructing past nutrient concentrations in the surface ocean are few and indirect. Here, we present laser ablation mass spectrometry results that reveal annual cycles of P/Ca in a 4-year record from the scleractinian coral Pavona gigantea (mean P/Ca = 118 mmol mol?1). The P/Ca cycles track variations in past seawater phosphate concentration synchronously with skeletal Sr/Ca-derived temperature variations associated with seasonal upwelling in the Gulf of Panama´. Skeletal P/Ca varies seasonally by 2–3 fold, reflecting the timing and magnitude of dissolved phosphate variations. Solution cleaning experiments on drilled coral powders show that over 60% of skeletal P occurs in intracrystalline organic phases. Coral skeleton P/Ca holds promise as a proxy record of nutrient availability on time scales of decades to millennia
Strengthened Techniques for the Renewed Industrial Interest in Plant Data Reconciliation Benefits
No full textThe renewed interest in the process data reconciliation by both the academic world and the process industries is mainly due to the introduction of new process control technologies such as the model predictive control, the real time dynamic optimization and the enterprise resource planning, all requiring a continuous (on-line) maintenance and optimization. The paper discusses the existing techniques for solving a data reconciliation problem, proposes some emerging methodologies, and introduces the open issue of the real-time nonlinear reconciliation based on detailed models
A New Method for Predicting Transport Properties via a State Equation for Mixtures. Gas and Liquid Phase Viscosities and Thermal Conductivities
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Modelling of Industrial Furnaces in Transient: A Reactor Charge Heater under Emergency Condition
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