Performance Evaluation of an IoT Sensor Node for Health Monitoring of Artwork and Ancient Wooden Structures

In this paper, an IoT sensor node, based on smart Bluetooth low energy (BLE), for the health monitoring of artworks and large wooden structures is presented. The measurements from sensors on board the node are collected in real-time and sent to a remote gateway. The sensor node allows for the monitoring of environmental parameters, in particular, temperature and humidity, with accurate and robust integrated sensors. The developed node also embeds an accelerometer, which also allows other mechanical quantities (such as tilt) to be derived. This feature can be exploited to perform structural monitoring, exploiting the processing of data history to detect permanent displacements or deformations. The node is triggered by acceleration transients; therefore, it can also generate alarms related to shocks. This feature is crucial, for instance, in the case of transportation. The developed device is low-cost and has very good performance in terms of power consumption and compactness. A reliability assessment showed excellent durability, and experimental tests proved very satisfactory robustness against working condition variations. The presented results confirm that the developed device allows for the realization of pervasive monitoring systems, in the context of the IoT paradigm, with sensor nodes devoted to the monitoring of each artwork present in a museum or in a church

A Photoacoustic-Based Measurement System for Dual Detection of NO2 and CO2 in Combustion Exhaust Gases

In this article, a low-cost, low-complexity photoacoustic (PA) sensing system for the simultaneous detection of CO2 and NO2 in exhaust gas is presented. The proposed system is designed as part of a continuous emissions monitoring system (CEMS) for gas turbine emissions. The system exploits the amplification of the PA signal provided by an acoustic ring resonator, which is characterized by a simple and robust structure and is suitable for in- field measurements. The dual gas detection is obtained by exploiting two measurement principles; the first one, dedicated to the detection of NO2, which is present in the target mixture in the ppm range, is the classical PA effect. In fact, the optical source is a light-emitting diode (LED) with a center wavelength of 405 nm matched on an adsorption peak of NO2. This allows for deriving the NO2 concentration measurement directly from the amplitude of the PA signal. The other mechanism is used to measure the concentration of one of the major components of the exhaust gas, with a concentration in the range of some percentage. The quantity of CO2 is sensed, exploiting its effect on the sound speed, and consequently on the resonance frequency of the resonator. To measure the CO2 concentration, the system automatically tracks the acoustic resonance shift. The detection of the two gases is realized simultaneously by a unique sensor with real-time measurements. A laboratory characterization of the proposed systems showed its feasibility. Experimental results show the possibility to detect NO2 with a resolution lower than 1 ppm, whereas CO2 resolution is about 0.2%

A Hazardous Area Personal Monitoring System for Operators in Gas Depots and Storage Tanks

This work describes a smart monitoring system for the detection of flammable gas residues, toxic gases, and reduced oxygen concentrations. The proposed system aims at reducing the risk of fires and explosions, thus increasing the safety of workers engaged in maintenance or inspection of gas storages. The monitoring system is based on compact battery-powered wearable sensor nodes containing sensors for LPG flammable compounds, toxic gases, and oxygen. The designed system can also increase plants safety by incorporating an intrusion detection system, which prevents unauthorized access to safety-critical areas to prevent accidents. The sensor nodes transmit data through a LoRa low power radio channel to a remote server whereas they allow for the identification of the operators for the access to restricted areas exploiting a Bluetooth Low Energy (BLE) proximity technique

SARS-CoV-2 vaccination modelling for safe surgery to save lives : data from an international prospective cohort study

Background: Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods: The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18-49, 50-69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results: NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion: As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population.Peer reviewe

Astrocyte networks and intercellular calcium propagation

International audienceAstrocytes organize in complex networks through connections by gap junction channels that are regulated by extra-and intracellular signals. Calcium signals generated in individual cells, can propagate across these networks in the form of intercellular calcium waves, mediated by diffusion of second messengers molecules such as inositol 1,4,5-trisphosphate. The mechanisms underpinning the large variety of spatiotemporal patterns of propagation of astrocytic calcium waves however remain a matter of investigation. In the last decade, awareness has grown on the morphological diversity of astrocytes as well as their connections in networks, which seem dependent on the brain area, developmental stage, and the ultra-structure of the associated neuropile. It is speculated that this diversity underpins an equal functional variety but the current experimental techniques are limited in supporting this hypothesis because they do not allow to resolve the exact connectivity of astrocyte networks in the brain. With this aim we present a general framework to model intercellular calcium wave propagation in astrocyte networks and use it to specifically investigate how different network topologies could influence shape, frequency and propagation of these waves

Ion current and exhaust gas composition measurements for combustion monitoring

The efficiency of combustion processes is assuming nowadays a huge importance, since the energy production, many industrial processes, as well as building heating systems are still mainly based on the combustion of hydrocarbons. The performance of the combustion process depends on many factors and it is a crucial point for the reliability and the efficiency of a plant or a thermal machine that exploits combustion as a primary source of energy. Moreover, the constant increasing of carbon dioxide concentration in atmosphere makes more and more important reducing the emission of this gas as well as the other pollutant/toxic chemical compounds that are produced during combustion. An optimized combustion process allows reducing dramatically the production of chemical compounds like carbon monoxide or nitrogen oxides, and also to releasing in the atmosphere the minimum amount of carbon dioxide per unit of energy produced. There are many studies related to the optimization of the internal combustion of the engines, especially for automotive applications, whereas the literature is less exhaustive for burner combustion optimization. The focus of this work is the study and the development of measurement systems allowing to get information about the combustion characteristics in gas turbines, with the aim of providing tools for monitoring/controlling the combustion parameters and keeping the combustion efficiency as high as possible over time. This activity has been developed in collaboration with Beker Huges (Nuovo Pignone Tecnologie - Florence), one of the world leaders in the design and development of gas turbines. Two different sources of information on the state of the combustion process have been considered in this thesis, namely the density of ions produced by the flame in the combustion chamber and the composition of the exhaust gases. The measurement of the ionic density due to the flame has been used since several years, particularly in the automotive sector, to obtain information about the combustion process: from the postprocessing of the signal obtained using ionization sensors (or ionic current sensors), it is possible to determine, for example, the onset of the combustion, the air–fuel ratio (and therefore the pollutant concentration at the exhaust), as well as to get information about the flame stability and the occurrence of periodic pressure variations in the combustion chamber. On this basis, even if the relationship between combustion parameters and flame induced ion density is highly dependent on the type of fuel, there is room to exploit the information of the ion sensors also with gas turbines, to optimize the operation of the combustor (e.g. reducing instability) and to monitor the polluting emissions. Ion or ionization sensors, which are usually used to measure the ion density in a burning gas, are essentially conductive electrodes capable of generating signals for either the charge transferred to/from the ionized gas and/or the charge induced on the electrodes themselves. The challenging issue concerns the choice of the materials for the sensor (electrodes and electrical insulators) which, being placed in the combustion chamber, must operate in extreme conditions, i.e., for example, in presence of very high temperatures. On the other hand, the conditioning front-end electronics for this kind of sensors is not critical. As far as the measurement of the concentration of toxic/pollutant compounds in exhaust gases is concerned, the most relevant compounds to be considered are carbon monoxide (CO) and nitrogen oxides (NOx). Monitoring CO and NOx in the exhaust gases is important not only from the point of view of environmental pollution, but also because their concentrations are useful and reliable indicators about the combustion efficiency. The drawback is that, due to the measurement procedure, they cannot be used for a timely feedback control of the combustion process, the reason is that the exhaust gases must be sampled from the chimney and pumped to the measurement instrument (gas analyser), and this procedure introduces a significant delay between the instant in which the gases are produced by the combustion and the time at which they are analysed. From the standpoint of the measurement instruments, exhaust gas analysers with different accuracies and costs (which are usually relevant) are available on the market. These devices can be portable or fixed and can exploit different measurement principles. Besides cost, an issue of these devices is that accurate gas sensors need frequent calibration exploiting reference gas tanks, which can be a problem in specific industrial plants such as power generation or oil and gas plants. The possibility to use a more flexible gas analyser, with a better trade-off among cost, measurement accuracy, the calibration intervals and robustness, is a deeply felt need in the oil & gas sector, considering also that these instruments are required to operate in environments that can be severely harsh, especially in terms of temperature and humidity. In this thesis, the developed and tested, in laboratory and in actual real test rigs of two measurement instruments, one for ion current measurements and one for exhaust gas composition measurement is discussed. For the first instrument, a theoretical model of the ion sensor used was also developed, which significantly helped in interpreting the experimental data

Progettazione dinastica: il caso Marpatech s.r.l.

Applicazione del metodo della "Progettazione dinastica" al caso Marpatech s.r.l., azienda inserita nell'ambito del packaging. Tale metodo viene applicato per la riorganizzazione della produzione, in particolare, in questo caso, della metodologia di lavoro all'interno dell'ufficio tecnico. Si è analizzata la varietà dei componenti che costituiscono le linee di trasporto facenti parte delle famiglie "trasporto sfuso" e "trasporto cartoni", per poi definire un capostipite della futura dinastia di prodotti e progettando componenti standard con logiche di modularità, range, fisso/variabile. Infine si sono applicati i risultati ottenuti ad una commessa realizzata nell'anno 2013 ed è stato fatto un confronto tra i due casi. L'obiettivo conseguito è stato ridurre la varietà dei prodotti, definendo il capostipite, e definendo i principali componenti standard, opzionali e speciali, e ridurre i costi e i tempi imputabili all'ufficio tecnico

Low Power Wide Area Networks (LPWAN) at Sea: Performance Analysis of Offshore Data Transmission by Means of LoRaWAN Connectivity for Marine Monitoring Applications

In this paper the authors discuss the realization of a Long Range Wide Area Network (LoRaWAN) network infrastructure to be employed for monitoring activities within the marine environment. In particular, transmission ranges as well as the assessment of parameters like Signal to Noise Ratio (SNR) and Received Signal Strength Indicator (RSSI) are analyzed in the specific context of an aquaculture industrial plant, setting up a transmission channel from an offshore monitoring structure provided with a LoRaWAN transmitter, to an ashore receiving device composed of two LoRaWAN Gateways. A theoretical analysis about the feasibility of the transmission is provided. The performances of the system are then measured with different network parameters (in particular the Spreading Factor—SF) as well as with two different heights for the transmitting antenna. Test results prove that efficient data transmission can be achieved at a distance of 8.33 km even using worst case network settings: this suggests the effectiveness of the system even in harsher environmental conditions, thus entailing a lower quality of the transmission channel, or for larger transmission ranges

Offshore LoRaWAN Networking: Transmission Performances Analysis Under Different Environmental Conditions

This paper presents the architecture and the performances of a Long Range Wide Area Network (LoRaWAN) infrastructure used for data transmission from a floating sensor node placed in the middle of the sea to a multi-Gateway structure positioned on the coast, whose purpose is the monitoring of offshore breeding cages within a fish farming plant. In particular, the sensor node is installed on a seamark buoy and it is interfaced with ad hoc sensors for the measurement of marine parameters. All sampled data are conveyed ashore to the Gateways by successfully covering the distance of 8.33 km. The paper presents the results concerning the performances of the data transmission for a 70 days operating period, analyzing the radio parameters (Signal-to-Noise Ratio - SNR and Received Signal Strength Indicator - RSSI) in relation with the variations of environmental parameters like temperature, relative humidity and atmospheric pressure as well as weather conditions. The proposed system demonstrates the usability of the LoRaWAN in all those cases where data collection from offshore monitoring structures is required: while this infrastructure focuses on the monitoring of fish farming plants, it may find application in several contexts, from navigational buoys to offshore oil plants