3D Simulation Methodology for n-Butanol Combustion in an optical accessible research GDI Engine

Abstract The strict political regulations in terms of engine tailpipe emissions and reduction of fossil fuel dependency are pushing forward the study of alternative fuels; these fuels must be suitable for currently available engines, in order to allow quick and inexpensive replacement. The alternative fuel chosen for this analysis is n-Butanol; being its key physico-chemical properties similar to those of commercial Gasoline, it does not require relevant changes in engine design and operation and therefore it is suitable for currently produced units. The paper describes the modeling and characterization of spark-ignited combustion of n-Butanol in comparison with that of conventional Gasoline. The comparison is made by means of 3D CFD simulations and experimental tests, carried out on a single-cylinder optically accessible engine characterized by a flat and transparent piston. The engine is equipped with direct injection and makes use of a current production engine head. The operating conditions used in the experiments are reproduced in the CFD simulations, in order to validate the CFD model and to provide additional insight to the experimental observations. The numerical simulation outcomes replicate with a good accuracy the experimental test results and they help to better understand the behavior of the alternative fuel during the combustion process. The adopted modelling methodology can therefore be used for further investigations such as exploration of different engine operations through virtual DOE of both operating and functional parameter variations

Banks, Firms, and Jobs

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Unmanned Aerial Vehicles for Debris Survey in Coastal Areas: Long-Term Monitoring Programme to Study Spatial and Temporal Accumulation of the Dynamics of Beached Marine Litter

Unmanned aerial vehicles (UAVs) are becoming increasingly accessible tools with widespread use as environmental monitoring systems. They can be used for anthropogenic marine debris survey, a recently growing research field. In fact, while the increasing efforts for offshore investigations lead to a considerable collection of data on this type of pollution in the open sea, there is still little knowledge of the materials deposited along the coasts and the mechanism that leads to their accumulation pattern. UAVs can be effective in bridging this gap by increasing the amount of data acquired to study coastal deposits, while also limiting the anthropogenic impact in protected areas. In this study, UAVs have been used to acquire geo-referenced RGB images in a selected zone of a protected marine area (the Migliarino, Massacciuccoli, and San Rossore park near Pisa, Italy), during a long-term (ten months) monitoring programme. A post processing system based on visual interpretation of the images allows the localization and identification of the anthropogenic marine debris within the scanned area, and the estimation of their spatial and temporal distribution in different zones of the beach. These results provide an opportunity to investigate the dynamics of accumulation over time, suggesting that our approach might be appropriate for monitoring and collecting such data in isolated, and especially in protected, areas with significant benefits for different types of stakeholders

Banks, Firms, and Jobs

We analyze the heterogeneous employment effects of financial shocks using a rich data set of job contracts, matched with the universe of firms and their lending banks in one Italian region. To isolate the effect of the financial shock, we construct a firm-specific time-varying measure of credit supply. The preferred estimate indicates that the average elasticity of employment to a credit supply shock is 0.36⁠. Adjustment affects both the extensive and the intensive margins and is concentrated among workers with temporary contracts. We also examine the heterogeneous effects of the credit crunch by education, age, gender and nationality

Is L-PRF an effective hemostatic agent in single tooth extractions? A cohort study on VKA and DOAC patients

Objectives: The aim of this clinical observational study was to assess the efficacy of L-PRF as a hemostatic agent in patients under treatment with vitamin K antagonists (VKAs) or direct oral anticoagulants (DOACs). Materials and methods: Patients under oral anticoagulant therapy (VKA or DOACs) who needed a single simple tooth extraction were enrolled. L-PRF plug was positioned inside the alveolus and secured with non-absorbable sutures. Surgical time, pain-VAS, paracetamol intake, intra-operative, post-operative biological complications, and bleeding events have been registered. Results: A total of 112 patients (59 patients for DOAC and 53 for VKA group) were enrolled. Post-operative bleeding was recorded in nine patients (17%) for VKA group and nine patients (15.3%) for DOACs group. None of the patients needed a medical support for managing of bleeding. Seven days after surgery, no cases of post-extractive complications occurred. Conclusions: The use of L-PRF resulted in limited mild late post-operative bleedings without the need of medical intervention. Clinical relevance: The use of L-PRF can be adopted for an uneventful post-operative curse in anticoagulated patients without chasing their therapy for single tooth extraction