Genetic Algorithm for the optimal placement of Self-Centering Damage-Free joints in steel MRFs

Nowadays' earthquake engineering is coping with the challenging task of providing low-cost seismic resilient structures. Among others, a viable solution for seismic resilient Steel Moment Resisting Frames (MRFs) is based on the use of Self-Centering Damage-Free (SCDF) joints at Column Bases (CBs) and Beam-to-Column Joints (BCJs), ensuring both the energy dissipation capacity and self-centering behavior of the structure. Past studies demonstrated the beneficial effects gained in damage and residual drifts reduction by including SCDF joints at all BCJs and CBs. However, this solution leads to the highest structural complexity, limiting the practical application. Significant improvements can be obtained including a limited number of SCDF BCJs, but there is a lack of generalized recommendations on the number required and their effective placement. In this work, a Genetic Algorithm (GA) is proposed to define the optimal placement of SCDF BCJs in steel MRFs. The GA is implemented in Matlab, and non-linear time-history analyses are performed in OpenSees to calculate the Fitness-Function. The results of the GA are validated against a Brute-Force Approach. An 8-story 3-bays steel MRF and a type of SCDF joint are selected for case study purposes, non-linear Finite Element Models are developed in OpenSees, and the GA is applied. The results show that the proposed GA is an efficient methodology to solve the considered optimization problem

Ottimizzazione del posizionamento di nodi ricentranti in telai momento resistenti in acciaio tramite un algoritmo genetico = Optimal Placement of Self-Centering Joints in Steel Moment Resisting Frames Through a Genetic Algorithm

Nowadays’ earthquake engineering is coping with the challenging task of providing low-cost seismic resilient structures. For Steel Moment Resisting Frames (MRFs) a viable solution is to use Self-Centering Damage-Free (SCDF) devices at Column Bases (CBs) and Beam-to-Column Joints (BCJs), ensuring both the energy dissipation capacity and the self-centering behavior of the structure. Past studies demonstrated the beneficial effects gained in damage and residual drifts reduction through the use of SCDF devices in all BCJs and CBs. However, this solution leads to the highest structural complexity and cost, limiting the practical application of these systems. Significant improvements can be obtained including a limited number of SCDF BCJs, but there is a lack of generalized recommendations on the number required and the effective placement. In this work, a Genetic Algorithm (GA) is proposed to define the optimal placement of a limited number of SCDF BCJs in steel MRFs. The GA is implemented in Matlab, and Non-Linear Time-History Analyses are performed in OpenSees to calculate the Fitness-Function based on residual drifts. An 8-story 3-bays steel MRF and a type of SCDF device are selected as case study and non linear Finite Element Models (FEM) are developed in OpenSees. The GA is applied assuming 16 SCDF BCJs and it is validated through a Brute Force approach. The results show that the proposed GA is an efficient methodology to solve the considered optimization problem. // Uno degli obiettivi principali dell'ingegneria sismica odierna è quello di progettare strutture sismo-resilienti a basso costo e tali da poter essere ampiamente utilizzate su larga scala. Per i telai momento resistenti in acciaio (MRFs), una possibile soluzione consiste nell'utilizzo di dispositivi dissipativi-ricentranti (SCDF) nei nodi trave-colonna (BCJs) e nodi di base (CBs) in modo da garantire sia la capacità dissipativa che il comportamento ricentrante della struttura. È stato dimostrato che l'uso di tali dispositivi in tutti i BCJs e CBs ha effetti benefici nella riduzione dei danni e degli spostamenti residui. Tuttavia, tale soluzione incrementa complessità e costo strutturale, limitando l'applicazione di questi sistemi nella pratica progettuale. Al fine di raggiungere un compromesso, studi precedenti hanno investigato l’utilizzo di un numero limitato di SCDF BCJs dimostrando che tali soluzioni possono fornire miglioramenti significativi in termini di prestazione sismica mantenedo una complessità ridotta. Tuttavia non ci sono ancora raccomandazioni generalizzate rispetto al numero di dispositivi necessario e al loro efficace posizionamento. In questo studio, viene proposto un Algoritmo Genetico (GA) per definire il posizionamento ottimale di un numero limitato di SCDF BCJs in MRFs in acciaio. Il GA è implementato in Matlab ed analisi dinamiche non lineari sono eseguite in OpenSees per calcolare la Fitness-Function basata sui drifts residui. Un MRF in acciaio con 8 piani e 3 campate e un tipo di dispositivo SCDF sono considerati per la definizione di un caso studio. Il GA è applicato assumendo 16 SCDF BCJs e validato rispetto un approccio Brute Force. I risultati mostrano che il GA proposto è una metodologia efficiente per risolvere il problema di ottimizzazione considerato

Seismic Behavior of Moment-Resisting Frames with Conventional and Innovative Connections

In the last few decades, increasing efforts have been devoted to the development of beam-to-column connections able to accommodate the local ductility demand dissipating, contemporaneously, the seismic input energy. Among the typologies proposed, the so-called RBS (Reduced Beam Section) has gained wide acceptance in the construction market, leading to easy-to-construct and cost-effective solutions. As an alternative, new proposals based on the inclusion of friction devices in beam-to-column joints have recently been made. Such a practice has the merit, in case of destructive events, of exhibiting wide and stable hysteretic cycles concentrating damage in elements that undergo only minor yielding. Both RBS and friction joints have been widely studied, carrying out experimental tests on sub-assemblies investigating their cyclic rotational response. Nevertheless, the available experimental results on full-scale structures equipped with these connections are still quite limited. This is the reason why two experimental campaigns aimed at performing pseudo-dynamic testing of a full-scale two-storey steel building equipped with RBS and friction connections have been planned at the STRENGTH (STRuctural ENGineering Test Hall) Laboratory of the University of Salerno. The first experimental campaign with the structure equipped with RBSs has already been performed; the connections showed higher resistance than expected, and exhibited brittle fracture due to cyclic fatigue. The second campaign has not yet been carried out, but in this paper the blind analysis of the supposed behavior is reported. It is expected that the friction joints allow to dissipate the seismic input energy without any structural damage in the members, but only through the friction pads of the devices, which can be easily replaced at the end of a severe seismic event

Boosting plant food polyphenol concentration by saline eustress as supplement strategies for the prevention of metabolic syndrome: an example of randomized interventional trial in the adult population

IntroductionPhenolic compounds in lettuce can increase by the application of positive stress (eustress) such as moderate saline stress. Phenolic compounds possess antioxidant capacity that is a key factor in the detoxification of excess reactive oxygen species. A double-blinded randomized interventional and placebo- controlled study design was carried out to compare the effect of daily dietary eustress lettuce ingestion in hepatic, lipid, bone, glucose, and iron metabolism.MethodsForty-two healthy volunteers, 19 female and 23 male participants, were divided into two groups. Participants were randomized into a polyphenol-enriched treatment (PET) arm or control arm. Each arm consumed 100 g/day of control or eustress (polyphenols enriched treatment = PET) lettuce for 12 days. Primary study outcomes were serological analysis for assessing hepatic, lipid, bone, iron, and glucose markers at baseline and after 12 days. Secondary outcomes assessed body composition.ResultsSalinity stress reduced plant yield but increased caffeic acid (+467%), chlorogenic acid (+320%), quercetin (+538%), and rutin (+1,095%) concentrations. The intake of PET lettuce reduced PTH, low-density lipoprotein (LDL), cholesterol, alanine transaminase (ALT), and aspartate transaminase (AST) enzyme levels and increased vitamin D and phosphate levels, while iron and glucose metabolism were unaffected.DiscussionSupplementation with eustress lettuce by increasing polyphenols concentration ameliorates hepatic, lipid, and bone homeostasis. Body composition was not affected.Clinical trial registrationhttps://classic.clinicaltrials.gov/ct2/show/NCT06002672, identifier: NCT06002672

Mechanical Modelling of the Strength and Stiffness of Circular Hollow Section Tube under Localised Transverse Compression and Tension

The component method is a powerful tool for designing and modelling steel beam-to-column connections. Its widespread use is ensured by several formulations currently included in Eurocode 3 part 1.8 for welded and bolted joints. However, the recent use of 3D Laser Cutting Technology (3D-LCT) in the construction market has enlarged the range of solutions, allowing the realisation of tubular columns with passing-through elements. Given the recent development, no design formulations are currently provided for this typology. At this moment, only a few research studies have developed to fill this knowledge gap. At the University of Salerno, since some years, research efforts are ongoing to characterise the flexural strength of connections between Circular Hollow Section columns and passing double-tee beams, suggesting methodologies to predict the behaviour of the resistance and stiffness of this typology and some of its elementary joint components. Within this framework, this paper aims to examine the strength and stiffness of one of the main components of this joint, which was never examined previously, that is the so-called tube under localised transverse tension/compression. Design formulations are derived from a parametric study carried out through numerical simulations of several geometric configurations

Seismic Behavior of Moment-Resisting Frames with Conventional and Innovative Connections

In the last few decades, increasing efforts have been devoted to the development of beam-to-column connections able to accommodate the local ductility demand dissipating, contemporaneously, the seismic input energy. Among the typologies proposed, the so-called RBS (Reduced Beam Section) has gained wide acceptance in the construction market, leading to easy-to-construct and cost-effective solutions. As an alternative, new proposals based on the inclusion of friction devices in beam-to-column joints have recently been made. Such a practice has the merit, in case of destructive events, of exhibiting wide and stable hysteretic cycles concentrating damage in elements that undergo only minor yielding. Both RBS and friction joints have been widely studied, carrying out experimental tests on sub-assemblies investigating their cyclic rotational response. Nevertheless, the available experimental results on full-scale structures equipped with these connections are still quite limited. This is the reason why two experimental campaigns aimed at performing pseudo-dynamic testing of a full-scale two-storey steel building equipped with RBS and friction connections have been planned at the STRENGTH (STRuctural ENGineering Test Hall) Laboratory of the University of Salerno. The first experimental campaign with the structure equipped with RBSs has already been performed; the connections showed higher resistance than expected, and exhibited brittle fracture due to cyclic fatigue. The second campaign has not yet been carried out, but in this paper the blind analysis of the supposed behavior is reported. It is expected that the friction joints allow to dissipate the seismic input energy without any structural damage in the members, but only through the friction pads of the devices, which can be easily replaced at the end of a severe seismic event

Odontogenic Sinusitis from Classical Complications and Its Treatment: Our Experience

Odontogenic sinusitis (ODS) refers to the maxillary sinus infection, which is secondary to either adjacent infectious dental pathologies or procedures. The aim of this retrospective study is to report the experiences of the department of integrated therapies in otolaryngology (Campus Bio-Medico Foundation, Rome, Italy) in classifying and treating patients that are affected by odontogenic sinusitis derived from “classic complications”. A total of 68 patients responding to the criteria and to the definition as a classical odontogenic complication were included. The surgical therapy consisted of a combined oral and nasal simultaneous approach for 28 patients (43%), a combined non-simultaneous approach for 4 patients (6%), a nasal only approach for 14 patients (21%), and an oral only approach for 20 patients (30%). All the patients presented a complete resolution of the symptoms. The choice of performing a nasal, oral, or combined approach is based on the presence of anatomical elements that facilitate sinusitis and reinfection occurrence, such as deviated nasal septum, concha bullosa, or obstructed osteo-meatal complex. The correct use of validated classification, the pre-operative CT scan, a multidisciplinary approach, and an appropriate presurgical examination are the necessary elements to obtain a good success rate

A New Lighting System for Surgical Vision Optimization in Barbed Pharyngoplasty for OSA

Obstructive sleep apnea (OSA) surgery is now a viable solution in selected patients and the “remodeling” palatopharyngeal surgery is the most common one. Recently, it has become less invasive with the introduction of barbed sutures (BS). An optimization of surgical techniques is represented by barbed pharyngoplasty (BP), which requires surgical precision and needs efficient and precise oropharyngeal visualization. Consequently, the lighting system is of pivotal importance in BP. The aim of this work is to describe the first experience on the use of a new lighting system, called KLAROTM in BP for OSA. We evaluated the KLARO™ system in 15 consecutives BP for OSA in comparison with conventional headlamp illumination. The visualization of palatopharyngeal muscle in the bottom of the tonsillar fossa, entry and exit needle, such as needle tip, were statistically better with KLAROTM than headlamp illumination for both the surgeon and resident (p TM lighting system allows a satisfied illumination of oral cavity and oropharynx in the majority of cases. We encourage the use of KLAROTM not only in BP for OSA, but in all oral and pharyngeal surgeries, including tonsillectomy and oncological surgery

Impact of proton pump inhibitors on the onset of gastrointestinal immune‐related adverse events during immunotherapy

Abstract Introduction The gut microbiota (GM) can influence the pathogenesis of immune‐mediated adverse events (irAEs). Proton pump inhibitors (PPIs) can affect the integrity of GM, but their role in promoting irAEs is still poorly understood. Methods In this retrospective single‐center cohort study, the primary endpoint was the evaluation of the incidence of gastrointestinal (GI) irAEs in cancer patients on PPIs (exposed) versus cancer patients who were not on PPIs (unexposed). Results Three hundred and sixty three patients' records (248 M/115F, median age 69) were reviewed. Twenty‐three exposed patients (92%) developed GI irAEs while only two unexposed patients (8%) developed GI irAEs (hazard ratio [HR] 13.22, 95% confidence interval [CI] 3.11–56.10, p < 0.000). This HR was confirmed after weighting for the propensity score (HR15.13 95% CI 3.22–71.03, p < 0.000). Conclusion Chronic PPI use is associated with an increased risk of GI irAES

Preliminary Study of a Seismic-Resilient Steel Pilot Building Equipped with Low-Damage Connections

According to current seismic design codes, in the case of rare seismic events, structures are designed to concentrate the seismic damage into dissipative fuses, characterized by high ductility and energy dissipation capacity. This approach allows the achievement of the safety requirements, with considerable damage to the structural components, thus compromising the building’s reparability. To overcome these drawbacks, recent efforts are aimed at developing innovative seismicresilient structures. In this direction, relevant research studies have been carried out within the RFCS-FREEDAM project, demonstrating the high potential of beam-to-column joints equipped with friction devices in drastically reducing the seismic damage of steel Moment Resisting Frames. The FREEDAM technology is going to be implemented in a demonstration building to be erected at the University of Salerno. The present paper illustrates the preliminary design and results of the numerical simulations in OPENSEES. Non-linear static analyses and Incremental Dynamic Analyses are performed to obtain the engineering demand parameters of interest while accounting for the record-to-record variability