A Novel Approach to Reduce the Environmental Footprint of Maritime Shipping

Maritime shipping is a strategic sector with a strong international vocation and management. The need to define regulations valid for many different countries without generating disparities of treatment slowed down the formulation of environmental regulations, especially for atmospheric emissions. In particular, regulations pertaining to the reduction of sulphur compounds allowed two distinct approaches: the use of low-sulphur fuels or exhaust gas cleaning systems, the so-called Scrubbers. The actual implementation of these solutions presents specific concerns either related to the toxicity of atmospheric by-products and to the fuel cost or to the generation of polluting washwaters that may need treatment before discharge. In this paper we analyzed the potential environmental benefit deriving from the use of a distillate fuel, not compliant with current IMO Sulphur Regulations, together with a Scrubber. The pilot-scale experimental results indicated that a limited amount of water and/or scrubber volume is needed to reduce sulphur emissions below regulations on maritime shipping, especially with the addition of NaOH reaching a water-saving between 25%-33% compared to the use of pure seawater. Experiments indicated that scrubber washwater PAHs emissions are within the available water quality standards indicated by EU and USA guidelines. A bottom-up analysis on heavy metals concentration shed light on the prominent role of metal-parts corrosion on the washwater emissions. Taking into account for corrosion phenomena, the actual heavy metals concentration in the washwater deriving from scrubbing was normally below the water quality standards

in vivo analysis of Drosophila deoxyribonucleoside kinase function in cell cycle, cell survival and anti-cancer drugs resistance.

in vitro studies have shown that Drosophila melanogaster has a highly efficient single deoxyribonucleoside kinase (dNK) multisubstrate enzyme. dNK is related to the mammalian Thymidine Kinase 2 (TK2) group involved in the nucleotide synthesis salvage pathway. To study the dNK function in vivo, we constructed transgenic Drosophila strains and impaired the nucleotide de novo synthesis pathway, using antifolates such as aminopterin. Our results show that dNK overexpression rescues both cell death and cell cycle arrest triggered by this anti-cancer drug, and confers global resistance on the fly. Moreover, we show that fly viability and growth depend on the exquisite ratio between dNK expression and its substrate thymidine (dT) in the medium, and that increased dT concentrations trigger apoptosis and a decrease in body mass when dNK is mis-expressed. Finally, dNK expression, unlike that of TK2, is cell cycle dependent and under the control of CyclinE and the dE2F1 transcription factor involved in the G1/S transition. dNK is therefore functionally more closely related to mammalian TK1 than to TK2. This strongly suggest that dNK plays a role in cell proliferation in physiological conditions

Application of Electrohydrodynamic Atomisation to Surface Disinfection

The development of improved methods for surface disinfection has gained renewed interest during the first waves of the SARS-COV2 Pandemic when the need to assure massive disinfection of objects and spaces goes against that of reducing the consumption of chemicals and minimize the impact of disinfectants on exposed persons. Electrohydrodynamic atomization is considered a valuable option to improve disinfection efficiency, thanks to the benefits associated with the droplets charge. This paper presents preliminary experimental and model results on the application of an induction charging electrohydrodynamic atomisation process to the spraying of water solution of a conventional disinfectant under model conditions. In particular, electrospraying under simple jet mode with a whipping breakup has been tested. Experiments are aimed to characterize the droplet size distribution, the energy requirements and the spray coverage area over a target surface, while a simplified physical mathematical model is used to estimate the amount of disinfectant lost upon evaporation and the distribution of the droplets over the target surface. The electrospray is able to disperse droplets having a charge-to-mass ratio of around 1.67 mC/kg with an energy consumption of 23.4±7.8 J/L, being more efficient than other conventional hydraulic nozzles. These preliminary findings indicate a good matching between modelled and experimental data and suggest that electrospraying under simple jet mode with a whipping breakup can be a possible option for the spraying of disinfectants over surfaces

Management of Low-Risk Thyroid Cancers: Is Active Surveillance a Valid Option? A Systematic Review of the Literature.

Thyroid cancer is the most common endocrine malignancy, representing 2.9% of all new cancers in the United States. It has an excellent prognosis, with a five-year relative survival rate of 98.3%.Differentiated Thyroid Carcinomas (DTCs) are the most diagnosed thyroid tumors and are characterized by a slow growth rate and indolent course. For years, the only approach to treatment was thyroidectomy. Active surveillance (AS) has recently emerged as an alternative approach; it involves regular observation aimed at recognizing the minority of patients who will clinically progress and would likely benefit from rescue surgery. To better clarify the indications for active surveillance for low-risk thyroid cancers, we reviewed the current management of low-risk DTCs with a systematic search performed according to a PRISMA flowchart in electronic databases (PubMed, Web of Science, Scopus, and EMBASE) for studies published before May 2021. Fourteen publications were included for final analysis, with a total number of 4830 patients under AS. A total of 451/4830 (9.4%) patients experienced an increase in maximum diameter by >3 mm; 609/4830 (12.6%) patients underwent delayed surgery after AS; metastatic spread to cervical lymph nodes was present in 88/4213 (2.1%) patients; 4/3589 (0.1%) patients had metastatic disease outside of cervical lymph nodes. Finally, no subject had a documented mortality due to thyroid cancer during AS. Currently, the American Thyroid Association guidelines do not support AS as the first-line treatment in patients with PMC; however, they consider AS to be an effective alternative, particularly in patients with high surgical risk or poor life expectancy due to comorbid conditions. Thus, AS could be an alternative to immediate surgery for patients with very-low-risk tumors showing no cytologic evidence of aggressive disease, for high-risk surgical candidates, for those with concurrent comorbidities requiring urgent intervention, and for patients with a relatively short life expectancy

On the Emergy accounting for the evaluation of road transport systems: an Italian case study

Road transportation is one of the most polluting as well as energy-intensive sectors, and requires planning policies capable to address at the same time several different environmental, social, and economic issues. Cost-benefit analyses are generally carried out with a major focus on fuelling and driving efficiency, whereas a systemic approach appears to be needed for a more comprehensive evaluation of the alternatives that may become available to address any issue, be it intended for either short-term or long-term spans. For instance, building up a new infrastructure might allow for savings in time or fuel per km, but this may require an equivalent or even higher socio-environmental investment. In this work, a short review is presented of some systemic studies on transportation that use the emergy synthesis methodology. A case study is also addressed, concerning recent important expansion works on the Apennine Mountains section of the Italian major highway A1. In particular, the analysis points out the role of time saving, since for a new or renewed transport infrastructure (and when comparing for example road to rail transport) saved time is likely to become crucial in justifying civil enterprises. Nevertheless, the present emergy synthesis and the teaching of H.T. Odum (Odum & Odum, 2001) warn us that such “luxury” highly depends on the abundance of available energy, which is less and less given for granted, whereas a systemic analysis approach may indicate different levels of criticality when oriented towards environmental and well-being issues

Enhanced Seawater Scrubbing for flue-gas Cleaning

This thesis work is focused on the development of new seawater-based scrubbing process for flue-gas cleaning, to be applied to both land-based industrial and power generation plants and to maritime shipping. Seawater scrubbing is receiving a growing attention mostly thanks to the diffusion of marine scrubbers for desulphurization of IFO fueled Marine Diesel Engines exhaust. The process is a viable option also for coastal infrastructures where seawater is abundant and it is funded on the exploitation of seawater alkalinity, which provides a valid and cost-effective sorbent for SO2. Seawater scrubbing can be improved by using caustic soda or other less common additives. Among them, oxidative reactants such as sodium chlorite (NaClO2), hydrogen peroxide (H2O2), ferrous-EDTA (Fe(II)-EDTA), sodium persulfate (Na2S2O8) or potassium ferrate (K2FeO4) have been suggested. This work adopts experimental and modelling methodologies to investigate the seawater scrubbing with caustic soda and sodium chlorite addition for the treatment of model flue gases as those coming from real marine diesel engines and coal/oil combustion plants. The work provides an analysis of SO2 solubility in the different water-based absorbing solutions and the estimation of the absorption efficiency of SO2 in packed and spray columns. The experiments are ruled out to define the optimal operating conditions for industrial and marine applications and to interpret how chemical reactions improve the mass transfer rate. The experimental campaign is supported by a dedicated modelling analysis accounting for equilibria, mass transfer and pressure drops in a unique framework, which is a valuable tool for the design of large scales applications. As a real case application, a comparison between spray and packed towers for a realistic marine engines is carried out, demonstrating that the packed tower can be a valid and cost effective solution, thanks to the far lower size and weight, which overcome the additional cost of packing. Finally, the effects of seawater-based scrubbing on the quality of the exhaust scrubbing solution are analyzed, for the possible capture of other gas pollutants. To this aim, a critical analysis of the properties of scrubber wash water in terms of heavy metals and organics is carried out. Test on real marine diesel engines shows that the emissions of heavy metals and organic compounds are in line with the current EU regulations on wash water discharge in natural water bodies and mostly of the analytes comply with the 2016/39/EU amendment of the Water Framework Directive. Finally, in order to further extend the field of investigation, the effect on other gaseous pollutants such as NOx of sodium chlorite seawater scrubbing is analyzed. Experimental evidences shows that sodium chlorite solutions provides a valuable removal of NOx compounds, opening to the possibility of a joint de-SOx/de-NOx process that is particularly advantageous for marine applications. In particular, the capture of NOx was promoted by the presence of SO2 in the exhausted gas and a complete removal can be achieved without any competitive effect. This was due to particular oxidation mechanisms occurring under acidic conditions arising during the absorption process

An evolutionary, structural and functional overview of the mammalian TEAD1 and TEAD2 transcription factors

International audienc

Effect of seawater alkalinity on the performances of a marine diesel engine desulphurization scrubber

Since the last fifteen years, Flue Gas Desulphurization (FGD) plants based on seawater scrubbing found an interesting application in the maritime transportation, as an answer to the stringent regulations imposed by International Maritime Organization (IMO) on sulphur emissions. This work reports the experimental results on desulphurization in a pilot seawater scrubber (DN 400) from a marine Diesel engine (80 kW) operated under different loads (10, 25 and 50%). The pilot scrubber was fed with a gas velocity 0.15 m/s and a liquid to gas mass ratio 1-3 kg/kg. The scrubbing liquid was available at different alkalinity and salinity levels representing the ion speciation of marine water in different geographic areas. The experiments evaluate the SO2 removal efficiency of the scrubber as a function of seawater alkalinity and pH. Finally, the paper reports a correlation to assess the seawater flow rate required to comply with the current IMO restrictions. This correlation allows tuning the seawater flow rate during the ship navigation based on the registered marine alkalinities and to the operating conditions of the engine. The model can be integrated in the scrubber control system to identify optimal operating conditions and reduce pumping costs, helping to reduce the EEDI and the SEEMP ships energy indexes

A Review on Gas-Liquid Mass Transfer Coefficients in Packed-Bed Columns

This review provides a thorough analysis of the most famous mass transfer models for random and structured packed-bed columns used in absorption/stripping and distillation processes, providing a detailed description of the equations to calculate the mass transfer parameters, i.e., gas-side coefficient per unit surface ky [kmol·m−2·s−1], liquid-side coefficient per unit surface kx [kmol·m−2·s−1], interfacial packing area ae [m2·m−3], which constitute the ingredients to assess the mass transfer rate of packed-bed columns. The models have been reported in the original form provided by the authors together with the geometric and model fitting parameters published in several papers to allow their adaptation to packings different from those covered in the original papers. Although the work is focused on a collection of carefully described and ready-to-use equations, we have tried to underline the criticalities behind these models, which mostly rely on the assessment of fluid-dynamics parameters such as liquid film thickness, liquid hold-up and interfacial area, or the real liquid paths or any mal-distributions flow. To this end, the paper reviewed novel experimental and simulation approaches aimed to better describe the gas-liquid multiphase flow dynamics in packed-bed column, e.g., by using optical technologies (tomography) or CFD simulations. While the results of these studies may not be easily extended to full-scale columns, the improved estimation of the main fluid-dynamic parameters will provide a more accurate modelling correlation of liquid-gas mass transfer phenomena in packed columns