Experimental test on an RC beam equipped with embedded barometric pressure sensors for strains measurement

The current trend in structural health monitoring (SHM) is to install increasingly large numbers of distributed, heterogeneous types of sensors, for a timely and exhaustive detection of any possible damage scenario evolving in the system. These sensors should be low-cost, easy to install, robust and durable. Among others, strain remains one of the most straightforward measurands for monitoring the state of a structural element and for assessing its health condition. However, for application to reinforced concrete structures, currently available strain sensing devices, such as electric strain gauges or fibre optic sensors, do not fully satisfy the aforementioned requirements, generally proving difficult to install, fragile and expensive. In this paper, an innovative monitoring technology, called Smart Steel System (S3), is proposed that measures strains in reinforced concrete members, by incorporating commercial barometric pressure MEMS sensors in appropriate sealed cavities embedded in the reinforcing steel bars. The results of an experimental campaign are reported, in which a reinforced concrete beam, instrumented with both S3 devices and conventional electrical strain gauges, is subjected to increasing loading and unloading cycles until collapse. The tests show the superior robustness of the S3 system during construction and loading as well as its good sensing accuracy, demonstrating its potential for a massive use in SHM applications

Intra-abdominal Adiposity In Preterm Infants: An Explorative Study

Objective: The aim of the present study was to compare the total body fat mass and the intra-abdominal adipose tissue between preterm infants assessed at term corrected age and full-term newborns. Methods: An observational explorative study was conducted. 25 preterm and 10 full term infants were evaluated at 0-1 month of corrected and postnatal age, respectively. The total body fat mass was assessed by means of an air displacement plethysmography system (Pea Pod COSMED, USA) and the intra-abdominal adipose tissue by means of magnetic resonance imaging (software program SliceOMatic, Version 4.3,Tomovision, Canada). Results: Total body fat mass (g) of preterm and term infants was 633 (±183) and 538 (±203) respectively while intra-abdominal fat mass (g) was 14.2 (±4.9) and 19.9 (±11.4). Conclusions: Preterm infants, although exhibiting a total body fat mass higher than full term infants, do not show an increased intra-abdominal adipose tissue

Vitamin D effects on bone homeostasis and cardiovascular system in patients with chronic kidney disease and renal transplant recipients

Poor vitamin D status is common in patients with impaired renal function and represents one main component of the complex scenario of chronic kidney disease–mineral and bone disorder (CKD–MBD). Therapeutic and dietary efforts to limit the consequences of uremia-associated vitamin D deficiency are a current hot topic for researchers and clinicians in the nephrology area. Evidence indicates that the low levels of vitamin D in patients with CKD stage above 4 (GFR < 15 mL/min) have a multifactorial origin, mainly related to uremic malnutrition, namely impaired gastrointestinal absorption, dietary restrictions (low-protein and low-phosphate diets), and proteinuria. This condi-tion is further worsened by the compromised response of CKD patients to high-dose cholecalciferol supplementation due to the defective activation of renal hydroxylation of vitamin D. Currently, the literature lacks large and interventional studies on the so-called non-calcemic activities of vitamin D and, above all, the modulation of renal and cardiovascular functions and immune response. Here, we review the current state of the art of the benefits of supplementation with native vitamin D in various clinical settings of nephrological interest: CKD, dialysis, and renal transplant, with a special focus on the effects on bone homeostasis and cardiovascular outcomes

A degrading Bouc\u2013Wen model for the hysteresis of reinforced concrete structural elements

This paper presents a smooth hysteresis model for reinforced concrete (RC) structural elements based on the differential equation of the Bouc?Wen model. Stiffness degradation and strength degradation are defined by introducing a damage index that includes both dissipated energy and maximum displacement. The pinching effect acts directly on the stiffness of the system and is controlled by an activation energy. The degrading functions are connected to the actual processes with which the damage occurs, thereby giving each parameter a physical meaning. The simple formulation of the model allows a straightforward identification of the best-fitting parameters and an easy interpretation of the results. Applications to the cyclic behaviour of RC structural elements demonstrate that the model is well capable of describing complex hysteretic behaviours involving degradation and pinching effects

A case report of IgG4-related disease: an insidious path to the diagnosis through kidney, heart and brain

BACKGROUND: IgG4-related disease, described around the years 2000 as a form of autoimmune pancreatitis, is now increasingly accepted as a systemic syndrome. The diagnosis is based on both comprehensive and organ-specific criteria. For the kidney, Mayo clinic classification and the guidelines of the Japanese Nephrology Society are used. Ultimately, together with parameters that characterize every organ or apparatus involved, the key element is the confirmation of growing levels of IgG4 in blood or in tissues. CASE PRESENTATION: We describe a male patient with chronic renal failure associated to hypertension without proteinuria. IgG4-related disease was diagnosed through renal biopsy. After an initial positive response to steroids, he presented tinnitus, and histological assessment showed cerebral and subsequently cardiac damage, both IgG4-related. This case appears unique for the type of histologically documented cardiac and neurological parenchymal involvement, and at the same time, exemplifies the subtle and pernicious course of the disease. Frequently, blurred and non-specific signs prevail. Here, kidney damage was associated with minimal urinary findings, slowly progressive renal dysfunction and other factors that can be equivocated in the differential diagnosis. Neurological involvement was represented by tinnitus alone, while cardiac alterations were completely asymptomatic. CONCLUSIONS: This report is representative of the neurological and cardiac changes described in the literature for IgG4-related disease, which may be correlated or not with the renal form and highlights the need, in some cases, of targeted therapeutic approaches. In addition to glucocorticoids, as in this case, rituximab may be necessary

Deconstruction of the Corso Grosseto viaduct and setup of a testing site for full scale load tests

BRIDGE|50 is a research project recently launched in Italy in the context of the Torino-Ceres construction works jointly with Politecnico di Milano, Politecnico di Torino, public authorities and private companies. The aim of the BRIDGE|50 research project is to investigate the residual structural performance of the Corso Grosseto 50-year-old prestressed concrete bridge through an experimental campaign. The dismantling and demolition procedures of Corso Grosseto viaduct are presented in this paper, including the setup of the field laboratory where several deck beams and pier caps will be tested up to collapse

Challenges in the reuse and upgrade of Pier Luigi Nervi 's structures

The paper presents the overall objectives of a funded research program for the development of a Conservation Plan (CP) for the two halls by Pier Luigi Nervi of the Turin Exhibition Center. The Turin Exhibition Center was conceived immediately after the Second World War to host primarily the annual Automobile Show, in connection with the presence in Turin of the FIAT motor company. The two main pavilions of the Center (Halls B and C) are outstanding examples of a pioneering use, of new advanced methods in reinforced concrete construction, combining innovative prefabrication procedures and the re-invention by Nervi of ferrocement, used to form extremely thin elements. The CP is expected to push and contribute to the preservation of the halls designed and built by Nervi, with special emphasis on structural and seismic vulnerability aspects, also due to concerns raised on the durability of concrete materials and technologies. Re-using these buildings entails the challenge to guarantee new extended service life to concrete structures built many decades ago and faces the need for a seismic assessment of these structures, in compliance to recent Italian standards

Towards a FOSS Automatic Classification of Defects for Bridges Structural Health Monitoring

Bridges are among the most important structures of any road network. During their service life, they are subject to deterioration which may reduce their safety and functionality. The detection of bridge damage is necessary for proper maintenance activities. To date, assessing the health status of the bridge and all its elements is carried out by identifying a series of data obtained from visual inspections, which allows the mapping of the deterioration situation of the work and its conservation status. There are, however, situations where visual inspection may be difficult or impossible, especially in critical areas of bridges, such as the ceiling and corners. In this contribution, the authors acquire images using a prototype drone with a low-cost camera mounted upward over the body of the drone. The proposed solution was tested on a bridge in the city of Turin (Italy). The captured data was processed via photogrammetric process using the open-source Micmac solution. Subsequently, a procedure was developed with FOSS tools for the segmentation of the orthophoto of the intrados of the bridge and the automatic classification of some defects found on the analyzed structure. The paper describes the adopted approach showing the effectiveness of the proposed methodology