Photoplethysmography and electrocardiography for real time evaluation of pulse transit time A diagnostic marker of peripheral vascular diseases

In this work, we report the results of a project, devoted to the development of a real time analysis for non-invasive monitoring of pulse transit time values on people affected by peripheral vascular diseases. Pulse transit time was computed as the time difference between every R-peak of the electrocardiographic signal and the following photopletysmographic peak. Both types of signals were acquired from 12 volunteers and real time signal analysis was performed in LabVIEW. Pathological conditions were simulated on every individual by means of an external cuff pressure applied on their arm. As expected, a PTT increase for increasing values of applied pressure was observed for all the volunteers. The proposed real time analysis could be suggested as a new, non-invasive optical method for real time monitoring of pulse transit time on patients affected by peripheral vascular diseases

Functional safety assessment of a liquid metal divertor for the European demo tokamak

A reliable strategy for the heat exhaust problem for fusion reactors is among the milestones indicated in EUROfusion (2018). In a fusion reactor, the divertor targets are subject to extremely large heat and particle fluxes. For fusion to be economically feasible, these conditions must be withstood without damage for long time. The “baseline” strategy will be employed for the ITER experiment (which is being built in France) and is based on actively cooled tungsten monoblocks. It is unclear whether this strategy will extrapolate to a future fusion reactor (such as the EU-DEMO, whose pre-conceptual design is ongoing within the EUROfusion consortium). For this reason, alternative solutions are under study, which will eventually be tested in a dedicated experiment in Italy, namely the Divertor Tokamak Test (DTT). One possibility is to employ liquid metal divertors (LMDs), for which the plasma-facing surface is inherently self-healing and immune to thermo-mechanical stresses. Within the framework of the pre-conceptual design of an LMD for the EU-DEMO, safety issues need to be considered at an early stage. In this work we present a preliminary but systematic safety analysis for this system, by means of the Functional Failure Mode and Effect Analysis (FFMEA). The FFMEA allows to identify possible accident initiators for systems undergoing pre-conceptual design, when more specific safety evaluations (e.g. at the component level) are not possible, US Nuclear Regulatory Commission (2009). This is done by postulating the loss of a system function rather than a specific component failure, thus compensating for the lack of detailed design information. For each function, the potential causes of its loss, a plausible evolution and preventive and mitigative measures are investigated, possibly specifying the need for further information. The initiating events are grouped according to consequences and the plant response. For each group, the Postulated Initiating Event (PIE) is chosen. The PIEs list drives and limits the set of accidental scenarios which will undergo deterministic analysis in a successive phase of the work, in order to evaluate the capacity of the system to withstand/mitigate its consequences. This will assess whether safety limits are respected or whether additional safety provisions are required. From the PIEs list, the design basis accident (DBA) and beyond design basis accident (BDBA) will eventually be selected

How underground systems can contribute to meet the challenges of energy transition

The paper provides an overview of the several scientific and technical issues and challenges to be addressed for underground storage of carbon dioxide, hydrogen and mixtures of hydrogen and natural gas. The experience gained on underground energy systems and materials is complemented by new competences to adequately respond to the new needs raised by transition from fossil fuels to renewables. The experimental characterization and modeling of geological formations (including geochemical and microbiological issues), fluids and fluid-flow behavior and mutual interactions of all the systems components at the thermodynamic conditions typical of underground systems as well as the assessment and monitoring of safety conditions of surface facilities and infrastructures require a deeply integrated teamwork and fit-for-purpose laboratories to support theoretical research. The group dealing with large-scale underground energy storage systems of Politecnico di Torino has joined forces with the researchers of the Center for Sustainable Future Technologies of the Italian Institute of Technology, also based in Torino, to meet these new challenges of the energy transition era, and evidence of the ongoing investigations is provided in this paper

Free-standing nanostructured gold films with milled nanopores for DNA analysis

Nanoporous thin films are of much interest for emerging DNA sequencing applications [1]. Klarite® pyramidal nanostructured substrates and gold microcavities have demonstrated strong field enhancement within their structure [2,3]. Our strategy has been to develop these three-dimensional structures in gold film form. As displayed in figure 1, free-standing thin films (100 nm thick) of arrays of nano-sized gold pyramids and microcavities have been successfully fabricated. Precisely engineered nanopores in the three-dimensional nanostructured free-standing gold film are milled at specific locations using a helium ion microscope (HIM). These films are suspended over micron-sized apertures for optical interrogation within platforms already proven for DNA translocation and sequencing. The strong field enhancement at the base of structures is currently being investigated for enhancement of fluorescently labelled DNA strands passing through the nanopores.We acknowledge the BBSRC (Ref: BB/I023720/1) and the CARIPLO Foundation, Italy for funding JAG-J and FC respectively and Renishaw Diagnostics, Glasgow for providing us with some of the samples used in fabricating these structures

Uncertainties on risk analysis : the consequence assessment in an hydrogen refuelling station

The paper concerns the problem of uncertainty associated to risk analysis of complex technological systems; this problem is not easy to resolve and manage. This is because such uncertainty has never been simple to quantify and, despite several innovative techniques able to properly manage uncertainties are available, none of these methodologies is integrated on the risk analysis in order to evaluate the error propagation. Also the itself risk analysis is not a precisely defined procedure but rather a complicated process of several parts and, moreover, each part is characterized by its own uncertainty. Several studies highlighted as the phases which mainly contribute to the overall uncertainty of a risk analysis are consequence and vulnerability studies. In order to provide a signifying approach to the problem, the working team has decided to focus their attention on a very important target for population safety: the hydrogen refuelling station for automotive