Dynamic Analysis of the Lubrication in a Wet Clutch of a Hydromechanical Variable Transmission

The paper investigates the oil flow through a multi plate clutch for a hydro-mechanical variable transmission under actual operating conditions. The analysis focuses on the numerical approach for the accurate prediction of the transient behavior of the lubrication in the gear region: the trade-off between prediction capabilities of the numerical model and computational effort is addressed. The numerical simulation includes the full 3D geometry of the clutch and the VOF multi-phase approach is used to calculate the oil distribution in the clutch region under different relative rotating velocities. Furthermore, the lubrication of the friction disks is calculated for different clutch actuation conditions, i.e. not-engaged and engaged positions. The influence of different geometrical features of the clutch lubricating circuit on the oil distribution is also determined. The results show the areas where poor lubrication occurs and extend the experiments where measurements are difficult to carry out. The simulation highlights the regions where high thermal stresses are observed during tests

Learning from the COVID-19 pandemic in Italy to advance multi-hazard disaster risk management

COVID-19 challenged all national emergency management systems worldwide overlapping with other natural hazards. We framed a ‘parallel phases’ Disaster Risk Management (DRM) model to overcome the limitations of the existing models when dealing with complex multi-hazard risk conditions. We supported the limitations analysing Italian Red Cross data on past and ongoing emergencies including COVID-19 and we outlined three guidelines for advancing multi-hazard DRM: (i) exploiting the low emergency intensity of slow-onset hazards for preparedness actions; (ii) increasing the internal resources and making them available for international support; (iii) implementing multi-hazard seasonal impact-based forecasts to foster the planning of anticipatory actions

Energy recovery of the biomass from livestock farms in Italy: the case of Modena Province

The energy recovery from manure of different Italian livestock farms is analysed by means of numerical simulation using an in-house developed code. In particular, the animal farming in the province of Modena is taken into account and biomass is exploited in an integrated system including different waste to energy technologies. In the considered system, the manure of a number of types of animals is fed into an anaerobic digester, while the digested sludge is separated into the solid and liquid fractions. The former is employed as a fuel in a downdraft gasifier, while the latter is purified by means of both forward and inverse osmosis. Finally, the obtained bio-gas and syngas are used in a cogeneration system based on a spark ignition internal combustion engine to produce electric and thermal power. The potential power production of the considered territory is estimated and compared with the energy requirements of the animal farms. Different strategies for the distributed exploitation of the manure versus a centralized solution are investigated and the relating plant size and production of electric energy and thermal energy are evaluated

Wipptal South Pilot Action Region: Gravity-Driven Natural Hazards and Forest Types

This chapter describes the Wipptal South Pilot Action Region (PAR) in South Tyrol, where forests are well recognized to play a crucial role in protecting against a variety of gravity-driven natural hazards, such as landslides, debris flows, rock falls and snow avalanches. The chapter presents the three municipalities in the PAR area in terms of socio-environmental context, gravity-driven natural hazards and forest characteristics. The presented best-practice example describes the results of a former project entitled “Waldtypisierung Südtirol” (Eng. Forest Characterization South Tyrol) that focused on a detailed description of forests in South Tyrol and the development of a handbook for foresters. It is shown that the Wipptal South PAR as being is frequently affected by a variety of gravity-induced hazards while highlighting the critical role of forest in protecting people and their properties. Appropriate forest management strategies are vital to maintain and increase tree species diversity (e.g. populating fir) and the associated protective forest function. In this context, climate change effects, such as an increasing threat of bark beetle infestation due to rising drought stress or the consequences of associated extreme weather events (e.g. storms), pose major challenges for the local forests and their protective function

Merging bio-optical data from Biogeochemical-Argo floats and models in marine biogeochemistry

In numerical models for marine biogeochemistry, bio-optical data, such as measurements of the light field, may be important descriptors of the dynamics of primary producers and ultimately of oceanic carbon fluxes. However, the paucity of field observations has limited the integration of bio-optical data in such models so far. New autonomous robotic platforms for observing the ocean, i.e., Biogeochemical-Argo floats, have drastically increased the number of vertical profiles of irradiance, photosynthetically available radiation (PAR) and algal chlorophyll concentrations around the globe independently of the season. Such data may be therefore a fruitful resource to improve performances of numerical models for marine biogeochemistry. Here we present a work that integrates into a 1-dimensional model 1314 vertical profiles of PAR acquired by 31 BGC-Argo floats operated in the Mediterranean Sea between 2012 and 2016 to simulate the vertical and temporal variability of algal chlorophyll concentrations. In addition to PAR as input, alternative light and vertical mixing models were considered. We evaluated the models\u2019 skill to reproduce the spatial and temporal variability of deep chlorophyll maxima as observed by BGC-Argo floats. The assumptions used to set up the 1-D model are validated by the high number of co-located in-situ measurements. Our results illustrate the key role of PAR and vertical mixing in shaping the vertical dynamics of primary produces in the Mediterranean Sea. Moreover, we demonstrate the importance of modeling the diel cycle to simulate chlorophyll concentrations in stratified waters at the surface

Structural and electronic properties of anisotropic ultrathin organic films from dichroic resonant soft x-ray reflectivity

We developed a quantitative approach for the determination of molecular arrangement and electronic structure in anisotropic organic ultrathin films based on the measurement of polarized reflectivity at the carbon K-edge. The reflectivity spectra were fitted to a parameterized model calculation. The method was applied to a self-assembled monolayer of 1,4-benzenedimethanethiol on gold. To simulate reflectivity, the organic anisotropic film was described by a dielectric tensor, obtained by ab initio calculations for the single molecule and suitable rotations to describe the molecular organization in film domains. Film structure was obtained though the best fit of the simulation to the experiment. Results were consistent with a monolayer-thick film composed of domains of molecules with in-plane isotropic distribution of orientations. In each domain, molecules adopted a standing configuration, with a tilt of 28° relative to the substrate normal. Information on the modification of the molecular electronic states due to chemical bonding was derived

Multi-risk assessment in mountain regions: A review of modelling approaches for climate change adaptation

Climate change has already led to a wide range of impacts on our society, the economy and the environment.According to future scenarios, mountain regions are highly vulnerable to climate impacts, including changes in the water cycle (e.g. rainfall extremes, melting of glaciers, river runoff), loss of biodiversity and ecosystems services, damages to local economy (drinking water supply, hydropower generation, agricultural suitability) and human safety (risks of natural hazards). This is due to their exposure to recent climate warming (e.g. temperature regime changes, thawing of permafrost) and the high degree of specialization of both natural and human systems (e.g. mountain species, valley population density, tourism-based economy). These characteristics call for the application of risk assessment methodologies able to describe the complex interactions among multiple hazards, biophysical and socio-economic systems, towards climate change adaptation.Current approaches used to assess climate change risks often address individual risks separately and do not fulfil a comprehensive representation of cumulative effects associated to different hazards (i.e. compound events). Moreover, pioneering multi-layer single risk assessment (i.e. overlapping of single-risk assessments addressing different hazards) is still widely used, causing misleading evaluations of multi-risk processes. This raises key questions about the distinctive features of multi-risk assessments and the available tools and methods to address them.Here we present a review of five cutting-edge modelling approaches (Bayesian networks, agent-based models, system dynamic models, event and fault trees, and hybrid models), exploring their potential applications for multi-risk assessment and climate change adaptation in mountain regions.The comparative analysis sheds light on advantages and limitations of each approach, providing a roadmap for methodological and technical implementation of multi-risk assessment according to distinguished criteria (e.g. spatial and temporal dynamics, uncertainty management, cross-sectoral assessment, adaptation measures integration, data required and level of complexity). The results show limited applications of the selected methodologies in addressing the climate and risks challenge in mountain environments. In particular, system dynamic and hybrid models demonstrate higher potential for further applications to represent climate change effects on multi-risk processes for an effective implementation of climate adaptation strategies

Spinal surgery complications: an unsolved problem—Is the World Health Organization Safety Surgical Checklist an useful tool to reduce them?

Abstract Purpose To investigate whether the World Health Organization Safety Surgical Checklist (SSC) is an effective tool to reduce complications in spinal surgery. Methods We retrospectively evaluated the clinical and radiological charts prospectively collected from patients who underwent a spinal surgery procedure from January 2010 to December 2012. The aim of this study was to compare the incidence of complications between two periods, from January to December 2010 (without checklist) and from January 2011 and December 2012 (with checklist), in order to assess the checklist's effectiveness. Results The sample size was 917 patients with an average of 30-month follow-up. The mean age was 52.88 years. The majority of procedures were performed for oncological diseases (54.4%) and degenerative diseases (39.8%). In total, 159 complications were detected (17.3%). The overall incidence of complications for trauma, infectious pathology, oncology, and degenerative disease was 22.2%, 19.2%, 18.4%, and 15.3%, respectively. No correlation was observed between the type of pathology and the complication incidence. We observed a reduction in the overall incidence of complications following the introduction of the SSC: In 2010 without checklist, the incidence of complications was 24.2%, while in 2011 and 2012, following the checklist introduction, the incidence of complications was 16.7% and 11.7%, respectively (mean 14.2%). Conclusions The SSC seems to be an effective tool to reduce complications in spinal surgery. We propose to extend the use of checklist system also to the preoperative and postoperative phases in order to further reduce the incidence of complications. Graphic abstract These slides can be retrieved under Electronic Supplementary Material

Denosumab in patients with aneurysmal bone systs: A case series with preliminary results

Abstract PURPOSE:: Aneurysmal bone cyst (ABC) is a rare skeletal tumor usually treated with surgery/embolization. We hypothesized that owing to similarities with giant cell tumor of bone (GCTB), denosumab was active also in ABC. METHODS:: In this observational study, a retrospective analysis of ABC patients treated with denosumab was performed. Patients underwent radiologic disease assessment every 3 months. Symptoms and adverse events were noted. RESULTS:: Nine patients were identified (6 male, 3 female), with a median age of 17 years (range 14-42 years). Primary sites were 6 spine-pelvis, 1 ulna, 1 tibia, and 1 humerus. Patients were followed for a median time of 23 months (range 3-55 months). Patients received a median of 8 denosumab administrations (range 3-61). All symptomatic patients had pain relief and 1 had paresthesia improvement. Signs of denosumab activity were observed after 3 to 6 months of administration: bone formation by computed tomography scan was demonstrated in all patients and magnetic resonance imaging gadolinium contrast media decrease was observed in 7/9 patients. Adverse events were negligible. At last follow-up, all patients were progression-free: 5 still on denosumab treatment, 2 off denosumab were disease-free 11 and 17 months after surgery, and the last 2 patients reported no progression 12 and 24 months after denosumab interruption and no surgery. CONCLUSIONS:: Denosumab has substantial activity in ABCs, with favorable toxicity profile. We strongly support the use of surgery and/or embolization for the treatment of ABC, but denosumab could have a role as a therapeutic option in patients with uncontrollable, locally destructive, or recurrent disease