Evaluating a Rapid Field Assessment System for Anticoagulant Rodenticide Exposure of Raptors
ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY
Authors: Dickson, Ariana J.; Belthoff, James R.; Mitchell, Kristen A.; Smith, Brian W.; Wallace, Zachary P.; Stuber, Matthew J.; Lockhart, Michael J.; Rattner, Barnett A.; Katzner, Todd E.
Abstract
Anticoagulant rodenticides (ARs) are commonly used to control rodent pests. However, worldwide, their use is associated with secondary and tertiary poisoning of nontarget species, especially predatory and scavenging birds. No medical device can rapidly test for AR exposure of avian wildlife. Prothrombin time (PT) is a useful biomarker for AR exposure, and multiple commercially available point-of-care (POC) devices measure PT of humans, and domestic and companion mammals. We evaluated the potential of one commercially available POC device, the Coag-Sense PT/INR Monitoring System, to rapidly detect AR exposure of living birds of prey. The Coag-Sense device delivered repeatable PT measurements on avian blood samples collected from four species of raptors trapped during migration (Intraclass Correlation Coefficient > 0.9; overall intra-sample variation CV: 5.7%). However, PT measurements reported by the Coag-Sense system from 81 ferruginous hawk (Buteo regalis) nestlings were not correlated to those measured by a one-stage laboratory avian PT assay (r = - 0.017, p = 0.88). Although precise, the lack of agreement in PT estimates from the Coag-Sense device and the laboratory assay indicates that this device is not suitable for detecting potential AR exposure of birds of prey. The lack of suitability may be related to the use of a mammalian reagent in the clotting reaction, suggesting that the device may perform better in testing mammalian wildlife
Three-dimensional modelling of the multiphase hydrodynamics in a separated-gasification chemical looping combustion unit during full-loop operation
JOURNAL OF CLEANER PRODUCTION
Authors: Wang, Xudong; Wang, Xiaojia; Shao, Yali; Jin, Baosheng
Abstract
Separated-gasification chemical looping combustion (SG-CLC) is a clean utilization technology for fossil fuels, which can separate CO2 during high-performance combustion process with low degradation of oxygen carrier and zero-energy penalty. As an important part of the optimization, modelling and prediction of the multiphase hydrodynamics in the SG-CLC unit were conducted in this work. This unit consists of a gasifier (GR), a reduction reactor (RR) and an air reactor (AR). For thorough understanding of the flow behaviors of three phases (gas, oxygen carrier and sand phases), a three-dimensional computational fluid dynamics (CFD) model for SG-CLC system was first implemented. The main purpose is to predict multiphase hydrodynamics at the fuel side of this SG-CLC system due to its significant effects on combustion efficiency. The axial pressure profile predicted by the CFD model was validated by experimental data to demonstrate its feasibility. Then, based on this model, the hydrodynamics of different phases at fuel side (GR and RR) were investigated under fundamental condition, which indicated the gas-solid flow mechanism in circulation establishment process. Furthermore, effects of the operation condition on the hydrodynamics properties were investigated. The local gas-solid slip velocity in RR was fitted as the function of superficial fluidizing number Nr and axial position, which showed high accuracy for the prediction in this system. (C) 2020 Elsevier Ltd. All rights reserved.