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1.
Can J Econ ; 55(Suppl 1): 406-445, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38607897

RESUMO

We develop a methodology to track and quantify the economic impacts of lockdown and reopening policies by Canadian provinces in response to the COVID-19 pandemic, using data that is available with a relatively short time lag. To do so, we adapt, calibrate and implement a dynamic, seasonally adjusted, input-output model with supply constraints. Our framework allows us to quantify potential scenarios that allow for dynamic complementarities between industries, seasonal fluctuations and changes in demand composition. Taking account of the observed variation in reopening strategies across provinces, we estimate the costs of the policy response in terms of lost hours of employment and production. Among other results, we show how a more aggressive response, even though it imposes higher economic costs in the short run, can lead to lower economic costs in the long run if it means avoiding future waves of lockdowns.


Quantification des impacts économiques des politiques associées à la COVID­19dans les provinces canadiennes en temps réel (ou presque). On développe une méthodologie pour identifier et quantifier les impacts économiques des mesures de confinement et des politiques de déconfinement dans chacune des provinces canadiennes en réponse à la pandémie de la COVID­19 en utilisant des données publiées avec un court décalage. Pour ce faire, on adapte, calibre et implémente un modèle d'entrées­sorties dynamique désaisonnalisé avec des contraintes au niveau de l'offre. Notre modèle nous permet de quantifier des scénarios potentiels qui incorporent les complémentarités dynamiques entre les industries, les fluctuations saisonnières et les changements dans la composition de la demande. En prenant en compte les variations observées dans les stratégies de déconfinement de chaque province, on estime les coûts des politiques en ce qui a trait aux pertes d'heures travaillées et de production. Parmi les autres résultats observés, on démontre qu'une réponse plus agressive, quoique plus coûteuse à court terme, peut mener à des coûts économiques moins élevés à long­terme si elle permet d'éviter des vagues de reconfinement.

2.
Water Environ Res ; 92(3): 347-358, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31232493

RESUMO

Anaerobically digested biosolids (ABD) characteristics that affect dewatering were assessed at three water resource recovery facilities (WRRF) with different handling practices. Dewatering performance at the three sites corresponded to different levels of soluble chemical oxygen demand (COD), ammonia (NH4 -N), and mono- and divalent cation concentrations in ADB. Capillary suction time (CST) and a modified centrifugal technique were used to determine optimum polymer doses and to assess the impact of handling conditions on dewatering performance. Both techniques indicated that polymer dosing between 15 and 20 kg/dry tonne was optimal for all facilities and that biosolids mixing and pumping did not significantly impact dewaterability. The CST values of anaerobically digested biosolids decreased as temperature increased, but no significant difference was found for either temperature or location of dewatering facilities. Sludge viscosity and rheological properties that vary with temperature appeared to have influenced CST values. Modified centrifugal technique results indicated cake solids were not affected by polymer make-up water or ADB temperature when emulsion polymer was used. This study shows the value of laboratory testing of biosolids under controlled conditions to identify and correct potential problems in full-scale operations. PRACTITIONER POINTS: Capillary suction time and a modified centrifugal technique were used to assess the impact of different process-related and environmental factors on dewatering. Higher concentrations of soluble COD (potentially extracellular polymeric substances - EPS) and low calcium (Ca) in anaerobically digested biosolids align with reduced dewaterability. Cell disruption and break down of floc structures due to storage/mixing and pumping of biosolids did not appear to negatively impact dewatering. Modified centrifugal test results did not provide conclusive evidence of whether dewatering of anaerobically digested biosolids could be significantly impacted by temperature over the range 15-30°C, especially when emulsion polymer is used. This study shows the value of laboratory testing of biosolids under controlled conditions to identify potential problems in the full-scale operations.


Assuntos
Biossólidos , Esgotos , Polímeros , Reologia , Eliminação de Resíduos Líquidos , Água
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