Multidimensional mobile mapping and integrated approach for the digitalisation of underground transport infrastructure

The tunnel industry has started focusing on the maintenance and management challenges of an existing infrastructure. It is an urgent matter in industrialised countries, where the stakeholders’ attention is increasing at a fast pace considering the incidents and the disruptions caused by improper monitoring and maintenance. This paper presents an innovative methodology to survey and inspect existing railway tunnels through multi-dimensional mobile mapping systems. The proposed approach belongs to the digital strategies for infrastructure maintenance. An integrated multidimensional survey system (ARCHITA) allows for collecting information necessary for the diagnostics of a structure with non-destructive tests. Linear cameras, thermographic cameras, and ground-penetrating radars acquire data to be digitalised and manipulated in different IT environments. The results, in terms of the collected data on structural defects, allow for a new approach for the Management and Identification of the Risk for Existing Tunnels (MIRET). The innovative approach aims at a smart integration of information and models for the Facility Management of the transport system. The workflow for the digitalisation and diagnosis from mobile mapping data has been implemented on two 40km-long metro tunnels

Digital transformation in the visual inspection of heritage railways tunnels: Technology, artificial intelligence and methodology

The knowledge, the preservation and the maintenance of heritage infrastructures is one of the most challenging matters facing modern civilization. It involves, in inextricable patterns, factors belonging to different fields (cultural, humanistic, social, technical, economical, administrative) coupled with the requirements of safety that can be in conflict with the integrity of part of the infrastructure. For these reasons, it is fundamental to carry out investigations and new planning strategies to know and predict the conditions of very old structures. The paper focused on heritage railway tunnels, one of the most crucial elements of the railway infrastructures in Europe. ETS Srl introduced a new method for diagnostic of existing tunnels through multi-dimensional mobile mapping systems, and a new approach for the Management and Identification of the Risk for Existing Tunnels. The approach belongs to the digital strategies for infrastructure maintenance that are very fast and minimally invasive. The integrated instrumentation allows to have almost all the information necessary for the diagnostics of a structure with non-destructive tests, preserving the integrity of very old structures in a phase of preliminary assessment. In such a way, the process of visual inspection is automatized and back-officed. The results, in terms of defects on the structures, are digitalized and manipulated in different IT environments. The results can be incorporated in the information modelling and virtual reality inspections. The use of artificial intelligence will be necessary to speed-up the back-office phase and introduce the technologies as a new inspection standard. A case study for the application is presented through the methodologies, including some preliminary applications of AI algorithms for the detection of water defects

Development Of A High Pressure Rotordynamic Test Rig For Centrifugal Compressors Internal Seals Characterization

Lecturepg. 46-59The current centrifugal compressor design for the Oil & Gas market is more and more challenging since the cost requirements and the presence of many competitors is pushing towards casing size reduction and rotational speed increase. The first requirement basically leads to increase the number of wheels per rotor and the second to cross more critical speeds requiring the proper degree of damping. The two consequences together lead also to increase the rotor flexibility ratio (defined as the ratio between the Maximum Continuous Speed and the first critical speed as per the Fulton diagram and API617 7th ed. [1-2]) and finally the rotordynamic stability is very much challenged. The centrifugal compressors rotordynamic stability is then strictly related to the internal seals’ dynamic behaviour and for this reason the authors’ Company decided several years ago to develop internally a High Pressure Seal Test Rig to measure seals’ stiffness and damping. The rig is now in operation. This paper aims to describe the main test rig capabilities, the applied identification procedures and the preliminary test results on a long labyrinth seal (smooth rotor - straight toothed stator). Due to the pressure level (500bar design pressure), the test rig plant appears like a high-pressure industrial plant equipped with the testing cell (a 1:1 scale high pressure compressor) and all the relevant auxiliaries: a 400 kW electric motor (driven by a VFD), a speed increaser gear box, a high pressure reservoir (6 m 3 ) with a volumetric compressor to fill it, high pressure pipes and valves. The testing cell is composed of a high-pressure compressor casing with stator parts capable to regulate the seal inlet swirl and a rotor running on Active Magnetic Bearings (AMBs), which serve as exciters (5kN MAX Force over a 0-330 Hz frequency range per axis) and displacement transducers. Special instrumentation is installed into the testing cell in order to measure the main test parameters: seal upstream/downstream gas pressure, upstream temperature and swirl and mass flow. Industrial high-pressure instrumentation is installed on the plant for regulation and monitoring purpose. Maximum test pressure is 350bar and maximum rotational speed is 15000rpm. Test gas is nitrogen. The AMBs control-system capabilities have been tuned to define several alternative excitation patterns and the relevant state of the art identification techniques have been applied. The first seal tested is a long labyrinth seal to simulate a centrifugal compressor balance piston seal. Test results and comparison with a commercial bulk flow code predictions will be fully described. Finally, the future test program will be showed

Cerebral Fat Embolism Syndrome: a case report

Fat embolism syndrome (FES) is a rare syndrome caused by embolization of fat particles into multiple organs including the brain (Cerebral Fat Embolism Syndrome), that can manifest itself in multiple ways, ranging from asymptomatic presentation to respiratory failure, neurocognitive deficits, and death. It typically manifests with petechial rash, deteriorating mental status, and progressive respiratory insufficiency, usually occurring within 2448 h of trauma with long-bone fractures or an orthopedic surgery. We present the case of a 30-year-old otherwise healthy man with an isolated femoral and radius fracture who developed signs of cerebral fat embolism syndrome (CFES) within 8 hours of injury and prior to any operative treatment

Sero-survey on long-term care facility residents reveals increased risk of sub-optimal antibody response to BNT162b2: implications for breakthrough prevention

Background The impact of coronavirus disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) on residents of long-term care facilities (LTCFs) has been dramatic on global scale as older age and comorbidities pose an increased risk of severe disease and death. Methods Aim of this study was to evaluate SARS-CoV-2 Spike-specific IgG (S-IgG) antibody titers in 478 residents and 649 health care workers of a large Italian long-term care facility two months after complete vaccination with BNT162b2. Associations among resident-related factors and predictors of humoral response were investigated. Results By stratifying levels of humoral responses, we found that 62.1%, 21.6%, 12.1% and 4.2% of residents had high (>1,000 BAU/ml), medium (101-1,000), low (1-100) and null (<1 BAU/mL) S-IgG titers, respectively. Residents with documented previous COVID-19 and those with SARS-CoV-2 nucleocapsid-specific IgG (N-IgG) positive serology showed higher level of serological response, while significant associations were observed for cancer with suboptimal response (p = 0.005) and the administration of corticosteroid for suboptimal response (p = 0.028) and a null one (p = 0.039). According to multivariate logistic regression, predictors of an increased risk of null response were advanced age (Odd ratio, OR: 2.630; Confidence interval, CI: 1.13-6.14; p = 0.025), corticosteroid therapy (OR: 4.964; CI: 1.06-23.52; p = 0.042) and diabetes mellitus (OR:3.415; CI:1.08-10.8; p = 0.037). In contrast, previous diagnosis of COVID-19 was strongly associated with a reduced risk of null response to vaccination (OR:0.126; CI:0.02-0.23; p < 0.001). Conclusions SARS-CoV-2 specific antibodies in elderly individuals should be consider when deciding the need of a third dose of vaccine for prevention of reinfections in LTCFs despite the maintenance of barrier measures

Durability of Humoral Responses after the Second Dose of mRNA BNT162b2 Vaccine in Residents of a Long Term Care Facility

Residents of long-term care facilities (LTCFs) have been dramatically hit by the COVID-19 pandemic on a global scale as older age and comorbidities pose an increased risk of severe disease and death. The aim of the study was to assess the quantity and durability of specific antibody responses to SARS-CoV-2 after the first cycle (two doses) of BNT162b2 vaccine. To achieve this, SARS-CoV-2 Spike-specific IgG (S-IgG) titers was evaluated in 432 residents of the largest Italian LTCF at months 2 and 6 after vaccination. By stratifying levels of humoral responses as high, medium, low and null, we did not find any difference when comparing the two time points; however, the median levels of antibodies halved overtime. As positive nucleocapsid serology was associated with a reduced risk of a suboptimal response at both time points, we conducted separate analyses accordingly. In subjects with positive serology, the median level of anti-S IgG slightly increased at the second time point, while a significant reduction was observed in patients without previous exposure to the virus. At month 6, diabetes alone was associated with an increased risk of impaired response. Our data provide additional insights into the longitudinal dynamics of the immune response to BNT162b2 vaccination in the elderly, highlighting the need for SARS-CoV-2 antibody monitoring following third-dose administration