Nanoparticles synthesis in wet-operating stirred media: Preliminary investigation with DEM simulations

The growing demand of nanomaterials is pushing towards the development of alternative strategies for the safe and sustainable production of nanoparticles. At the same time, to ensure high performances, a fine control over the product specifications is required. We focused on a bottom-up method combined with a mechanical disaggregation technique using a wet bead-stirring process, since it provides numerous advantages over other approaches, including the minimization of the nanoparticles air dispersion and a greater control over the final product. However, given the broad variability of the parameters involved in both the setup and operation of the process, it is essential to combine the experiments with a theoretical-simulative study to optimize the design. The present activity consists in the preliminary simulation of the interactions among the grinding beads, modelled through the discrete element method (DEM), and the magnetic stirrer. This approach, providing information regarding the frequency and energy of collisions, which can be related to the properties of the produced nanoparticles, allows a fine tuning of the process parameters

Safety Concerns and Chemical Aspects of Improvised Explosive Devices and Homemade Explosives

The continuous changes in socio-political scenarios of the last decades led to an impressive increase in terrorist events related to the use of improvised explosive devices (IEDs). The energetic material contained in them, representing the essential part of the apparatus, is object of intense investigation owing to the need of optimizing many variables, namely the chemical energy storage of the detonating compound, the availability of raw materials required for its synthesis, the ease of process synthesis by commonly used tools and the stability of the chemical energy carrier towards transport and handling. This critical analysis proposes a classification of the detonating compounds or mixtures according to their chemical, thermodynamic and ballistic properties that make them basic ingredients in IEDs and homemade explosives. The wide and always growing variety of ingredient combination poses a challenging problem of chemical identification, owing to an interference of signals in analytical data regression. Finally, a discussion on technical realizations of such improvised weapons is outlined in light of the recent protocols of process safety and disaster control

Can the BestGrid process improve stakeholder involvement in electricity transmission projects?

The European Union has set ambitious targets for deployment of renewable energy sources to reach goal of climate change mitigation and energy security policies. However, the current state of electricity transmission infrastructure is a major bottleneck for further scaling up of renewable energy in the EU. Several thousands of kilometers of new lines have to be constructed and upgraded to accommodate growing volumes of intermittent renewable electricity. In many countries, construction of electricity transmission projects has been delayed for several years due to concerns of local stakeholders. The innovative BESTGRID approach, reported here, brings together transmission system operators (TSOs) and non-governmental organizations (NGOs) to discuss and understand the nature of stakeholder concerns. This paper has three objectives: (1) to understand stakeholder concerns about the deployment of electricity transmission grids in four pilot projects according to five guiding principles: need, transparency, engagement, environment, and impacts on human health as well as benefits; (2) to understand how these principles can be addressed to provide a basis for better decision-making outcomes; and (3) to evaluate the BESTGRID process based on feedback received from stakeholders and the level of participation achieved according to the ladder of Arnstein. This paper goes beyond a discussion of "measures to mitigate opposition" to understand how dialogue between TSOs and the public -represented mainly by NGOs and policy-makers- might lead to a better decision-making process and more sustainable electricity transmission infrastructure deployment

Impact of chronic liver disease upon admission on COVID-19 in-hospital mortality: Findings from COVOCA study

Background Italy has been the first Western country to be heavily affected by the spread of SARS-COV-2 infection and among the pioneers of the clinical management of pandemic. To improve the outcome, identification of patients at the highest risk seems mandatory. Objectives Aim of this study is to identify comorbidities and clinical conditions upon admission associated with in-hospital mortality in several COVID Centers in Campania Region (Italy). Methods COVOCA is a multicentre retrospective observational cohort study, which involved 18 COVID Centers throughout Campania Region, Italy. Data were collected from patients who completed their hospitalization between March-June 2020. The endpoint was in-hospital mortality, assessed either from data at discharge or death certificate, whilst all exposure variables were collected at hospital admission. Results Among 618 COVID-19 hospitalized patients included in the study, 143 in-hospital mortality events were recorded, with a cumulative incidence of about 23%. At multivariable logistic analysis, male sex (OR 2.63, 95%CI 1.42–4.90; p = 0.001), Chronic Liver Disease (OR 5.88, 95%CI 2.39–14.46; p<0.001) and malignancies (OR 2.62, 95%CI 1.21–5.68; p = 0.015) disclosed an independent association with a poor prognosis, Glasgow Coma Scale (GCS) and Respiratory Severity Scale allowed to identify at higher mortality risk. Sensitivity analysis further enhanced these findings. Conclusion Mortality of patients hospitalized for COVID-19 appears strongly affected by both clinical conditions on admission and comorbidities. Originally, we observed a very poor outcome in subjects with a chronic liver disease, alongside with an increase of hepatic damage

Use of hydroxychloroquine in hospitalised COVID-19 patients is associated with reduced mortality: Findings from the observational multicentre Italian CORIST study

Background: Hydroxychloroquine (HCQ) was proposed as potential treatment for COVID-19. Objective: We set-up a multicenter Italian collaboration to investigate the relationship between HCQ therapy and COVID-19 in-hospital mortality. Methods: In a retrospective observational study, 3,451 unselected patients hospitalized in 33 clinical centers in Italy, from February 19, 2020 to May 23, 2020, with laboratory-confirmed SARS-CoV-2 infection, were analyzed. The primary end-point in a time-to event analysis was in-hospital death, comparing patients who received HCQ with patients who did not. We used multivariable Cox proportional-hazards regression models with inverse probability for treatment weighting by propensity scores, with the addition of subgroup analyses. Results: Out of 3,451 COVID-19 patients, 76.3% received HCQ. Death rates (per 1,000 person-days) for patients receiving or not HCQ were 8.9 and 15.7, respectively. After adjustment for propensity scores, we found 30% lower risk of death in patients receiving HCQ (HR=0.70; 95%CI: 0.59 to 0.84; E-value=1.67). Secondary analyses yielded similar results. The inverse association of HCQ with inpatient mortality was particularly evident in patients having elevated C-reactive protein at entry. Conclusions: HCQ use was associated with a 30% lower risk of death in COVID-19 hospitalized patients. Within the limits of an observational study and awaiting results from randomized controlled trials, these data do not discourage the use of HCQ in inpatients with COVID-19

Improved management of water resources in process industry by accounting for fluctuations of water content in feed streams and products

In this paper, a general strategy is presented for optimizing water resources in industrial activities taking into account fluctuations of water flow-streams and water contents in feed and products as well as in the utility system. Indeed, considering fluctuations can be of primary importance for several water intensive industries such as the food or the paper&pulp industry. Furthermore, whenever the water balance includes the water content of products (as is typically the case for the food industry) fluctuations in the composition of products can considerably affect the overall balance due to water being a major component of many foods. Therefore, the currently used optimization strategies that disregard water fluctuations, can lead to a severe bias in the water balance and thus overlook the potential of water recovery and reuse. Including this aspect in widely used algorithms for process monitoring (data reconciliation) and optimization might lead to a possibly prohibitive increase in the computational burden. In particular, it is shown in this paper that the resulting optimization algorithm should solve a dynamic non-convex stochastic Mixed Integer Nonlinear Programming problem. To tackle this (typically NP-hard) problem, a strategy has been developed that combines ordinal optimization for dealing with statistical information and nonlinear, non-convex deterministic algorithms. The outlined strategy has been applied to a complex process in the food industry (production of starch and starch-based products). The results seem to confirm the general validity of the algorithm developed

Application of Advanced Electrochemical Techniques for the Purification of Leachate in Landfills

Landfill leachate is one of the problems related to waste landfills with the most important environmental impact, as the extreme variability of the substances inside the landfill gives rise to high heterogeneity of the leachate itself. In the present work, an electrochemical approach has been considered as a relatively simple and low-cost solution to the problem of ammonia removal, given the impossibility of resorting to biological treatments. An extensive experimental campaign was conducted to identify the best solution, evaluating any preventive filtration or precipitation sections, and considering the efficiency of the process in terms of energy costs. Based on the data obtained, the electrochemical approach appears feasible, and it is possible to operate either with high current densities (and higher energy costs) or with lower current densities (which, in addition to lower energy costs, allow longer service life for the electrodes), after pre-treatment of the solution by coagulation/flocculation with aluminum polychloride

Pillow-Plate Heat Exchangers: An Overview on Advances, Limitations and Prospects

Pillow-plate heat exchangers (PPHEs) represent an innovative and promising alternative to conventional equipment. The waviness of the pillow-plates promotes lateral mixing and turbulence, which results in a good thermo-hydraulic performance, offering a significant energy-saving potential. Since PPHE also offer several important structural and cost related advantages over conventional heat exchangers, e.g. compact, light and pressure-resistant construction, low pressure drop on the product media side, as well as low capital and operating costs, their use in process industries is growing. However, the implementation of PPHE is still limited due to the lack of comprehensive data and publicly available proven design methods, while their range of applicability has not yet been fully determined. The purpose of this contribution is to present the current state of the art of PPHE, with particular attention to recent advances in terms of modelling and prediction of the performance of such equipment, while highlighting the advantages in terms of sustainability and efficiency of the various applications compared to conventional solutions. In addition, the future prospects in modelling and application of these devices will also be delineated

Eco-friendly and cost-effective strategies for metals recovery from printed circuit boards

The possible optimization of metal recovery from Printed Circuit Boards (PCBs)and Central Processing Units (CPUs)has been investigated. Usual practice is to recover primarily the metals with the highest market price. In contrast, the present work shows how strategic considerations of the value share (%)of metals content and data regarding the environmental impact of their recovery can instruct about the best strategies to adopt, pointing at the metals to be recovered as a priority depending on the case. An accurate PCBs\u2019 characterization carried out through microwave digestion with a mixture of HNO3, HF and HCl, is a first essential step of the procedure. Then, metals are recovered through chemical leaching with different chemical substances, exploiting both chemical and physical steps. A proposal is presented to improve the environmental and economic sustainability of the treatment of PCBs, which provides for the initial recovery of Cu, Pb and Sn from the whole boards, through leaching with 6M HNO3, followed by the recovery of gold and other precious metals from the board components once removed and appropriately crushed. Although unusual, the recovery procedure can be adapted accordingly, allowing greater profits, easier management and higher metals recovery rates