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For large scale magnets wound with cable-in-conduit conductors, the safe operation of the joints is of paramount importance to guarantee adequate reliability and stability margin of the whole magnet. For this reason, during the R&D activities undertaken for the development of the ITER magnet system, several experimental campaigns were launched to study the AC and DC performance of the joint and limit the risk of thermal runaways at the joints during the tokamak operation. The joint electrical resistance must be limited below specified values to avoid excessive heating generated by the transport current. Moreover, in presence of time-varying fields, different type of losses arise at the joints, which can be associated to their superconducting and resistive parts. The relative importance of these losses depends on the joint manufacturing solution. The aim of this investigation is to analyse the performance at different working conditions of the joints for the connection of the conductors of the Poloidal Field (PF) coils of the ITER magnet system. This work presents, for the first time, a wide review of the test campaign performed from 2016 to 2021 on the PF joint samples during the three manufacturing phases, namely pre-qualification, qualification and production. The values of electrical resistances and losses under sinusoidal field variations are reported in the paper at different operating conditions, thus building a useful database to assess the joint performances during the machine operation. The data here collected show the impact of the manufacturing techniques on the joint performances and, furthermore, represent a useful tool for the validation of numerical and analytical models of joints.

This paper analyses the current distribution in no-insulation (NI) coils in a layer-wound configuration. The investigation aims at comparing the electrical characteristic of two coils wound from the same BSCCO tape, with or without electrical insulation between turns. Both coils are characterized by a very similar geometry, with the same number of turns and layers. Both coils, cooled in liquid nitrogen bath, are charged until the tape critical current is exceeded. To interpret the measurements and analyze the current distribution within the winding, a lumped-parameter equivalent electrical circuit is developed and solved numerically in a time-varying regime. The model results are compared with the signals acquired through voltage taps soldered at the same locations in both coils. Finally, the model is applied to investigate the impact of the transverse contact resistance and to estimate the most stressed locations of the coil during charging, in terms of power produced by Joule effect.

The measurement of transport current ac losses in high-temperature superconductor tapes with the electric method has been extensively discussed in the literature. It is well known that the configuration of the circuit used to acquire the voltage signal can affect the measured losses, potentially leading to inaccurate results. To reduce this undesired effect, the rectangular circuit arrangement, which is widely adopted, involves twisting the pair of voltage taps at a given distance from the tape middle axis. However, the explanations reported in the literature to identify the correct distance are not fully exhaustive, and an alternative interpretation is described here. Moreover, given that the conventional voltage taps arrangement creates a significant circuit area to which electromagnetic noise can be linked, an alternative configuration is proposed, aiming to reduce the linked flux. This article presents a theoretical analysis to quantify the impact of the measurement circuit configuration on the losses. To ensure clarity, the model equations involved are derived step by step. The numerical results are applied to a thorough investigation on the accuracy of the ac losses measured on a sample tape, at different frequencies and current amplitudes. Both the conventional and the alternative arrangements are studied, varying their main geometrical parameters, at the same operating conditions. The correction terms are then applied to the measurement results, highlighting the advantages and drawbacks of the different configurations.

Aims Left atrial appendage (LAA) membranes are rare congenital anomalies. Those involving the appendage orifice may obstruct its emptying flows, thus promoting blood stasis and clot formation. However, the epidemiology of LAA membranes has never been studied and a correlation with appendage thrombosis has never been proved. Very few case reports described LAA membranes, therefore, their frequency and clinical significance are not known. Moreover, their presence and degree are of crucial importance in planning LAA percutaneous closure, a procedure whose indication is evolving, and whether their presence can represent technical issues during the device implantation is not known. This study aimed to evaluate the incidence and the clinical significance of LAA membranes. Methods and results A population of 6030 consecutive transoesophageal echo (TOE) studies has been retrospectively reviewed in order to find those patients in whom an LAA membrane has been found. A literature research has been performed to review previous described cases. Among 6030 TOE cases, an LAA membrane has been described in 6 (prevalence of 1/1000). In one case, the membrane was associated to a severe LAA hypoplasia and in another case to an LAA thrombus (these represent the first cases ever described). All patients had an atrial fibrillation (AF) history and two were in AF during the TOE exam. Conclusion LAA membranes are rare congenital abnormalities occasionally discovered during a TOE exam, frequently in patients affected by AF. In half of the cases, they obstruct the LAA flow, thus theoretically pre-disposing to clot formation. They may be rarely associated to an appendage hypoplasia. During a TOE exam, cardiac imagers should always rule out their presence.

The role of maternal nutrition in affecting offspring fertility, through alteration of foetal programming, has been demonstrated in animal-based experiments. However, results from human populations appear inconsistent and sometimes contradictory, likely because they have been based on single famine events. In this paper, we adopt a different approach. We combine official annual time series of daily nutrient availability with a sample of women's reproductive histories from the 1961 Italian Census to investigate the role of maternal nutritional status in pregnancy on offspring childlessness. The analysis therefore covers cohorts of females born between 1861 and 1939. Our results show a negative association between calorie availability in pregnancy and the odds of offspring childlessness, whereas no association is found between protein availability and offspring childlessness. The consequences of poor calorie intake were aggravated during the summer, likely due to the participation of pregnant women in physically demanding work.

Ventricular tachycardia and premature ventricular complexes (PVCs) arising from right ventricular outflow tract (RVOT) are the most common type of ventricular arrhythmias (VAs) in patients without structural heart disease. Radiofrequency ablation is now the gold standard of treatment in this setting due to high efficacy rates and optimal safety profile. During the last few years, the pulmonary valve (PV) and the pulmonary artery (PA) have attracted much attention as reliable sites of origin of RVOT-type arrhythmias. In the mean while intracardiac echocardiogram (ICE) has undoubtedly improved our understanding of the cardiac anatomy. Aim of this paper is to provide an illustrated step-by-step guide on how to use ICE with the CARTOSOUND module to visualize and reconstruct 3D shell of the RV, the PV, as well of other contiguous anatomical structures (i.e., the aortic valve and coronary arteries) to perform aware and safe ablation in this region. This article is protected by copyright. All rights reserved.

This article presents a numerical model based on the definition of the scalar and vector potentials to calculate the ac losses generated in a high-temperature superconductor coated conductor tape by an ac transport current and by an ac external magnetic field applied with a generic orientation. The material characteristics of the different layers of a reference tape are included in the model equations, which allow analyzing the differences between a model including only the superconducting layer or all layers of the coated conductor. The model is applied to study the dependence of ac losses on the amplitude of the transport current and magnetic field (applied individually or combined) and their frequency. The numerical results are compared with analytical formulations, with a second numerical model based on the H -formulation, and with experimental results. The conditions at which the contribution of the nonsuperconducting layers to the total ac losses of the tape become relevant are analyzed. In particular, the dependence of losses on the frequency of the ac external magnetic field applied at different orientations, is investigated. The current density distribution computed on the conductor cross-section is used to explain the trend of the calculated losses.

Les differences regionales ont toujours ete presentes dans l’histoire socioeconomique de l’Italie, et elles ont profondement marque la demographie de chaque region. La mortalite maternelle compte parmi ces differences, dans son rapport aux depenses de sante publique, aux sages femmes, au role social de la femme, a l’analphabetisme et l’incroyance en la science medicale, et au statut socioeconomique.Le but de cet article est precisement d’eclairer les differentiels regionaux de mortalite maternelle en Italie entre 1887 et 1955, ainsi que leur role dans le declin d’un tel phenomene. L’analyse utilise les statistiques officielles sur les causes de deces ; ces statistiques commencent a couvrir tout le territoire national en 1887.L’etude montre que les regions italiennes du Sud presentent les plus faibles valeur de mortalite maternelle, surtout au debut de la periode etudiee, probablement a cause du taux d’emploi feminin dans les industries, inferieur a celui des regions du Nord, et a cause d’une tendance plus forte a l’accouchement a domicile, qui peut reduire le risque d’infections, etant donne les tres forts taux de mortalite due a cette cause documentes dans les maternites avant l’introduction de techniques antiseptiques.

Ultrasound (US)-guided axillary vein cannulation is effective and safe during cardiac implantable electronic devices (CIEDs). It is a reasonable alternative to other techniques in order to shorten procedural time and decrease perioperative complications. However, in this context, the short-axis (out-of-plane) visualization to guide the vein puncture is the most used technique. The aim of our study is to describe a single-center experience with the US long-axis (in-plane) technique defining predictors of unsuccessful puncture attempts and failure to axillary vein cannulation in a cohort of patients undergoing CIEDs procedures. From November 2017 to June 2019, consecutive patients undergoing CIEDs procedures were enrolled in the study. US-guided long axis (in-plane) view to guide axillary vein cannulation was used in all subjects. Unsuccessful puncture attempts (UAs) and complete failures to cannulate the vein were collected for each procedure. All patients were evaluated on a daily basis until hospital discharge and at 1-month follow up visit. Among 119 subjects (M: F = 75:44), mean age was 79 ± 9 years, mean BMI 25.7 ± 4.3 kg/m2, and mean BSA 1.74 ± 0.4 m2. We placed 95 pacemakers (32 single-, 61 dual-, and 2 triple-chamber) and 20 ICDs (7 single, 6 dual, 7 triple chambers). An upgrade from dual-chamber to triple-chamber device was carried out with the addition of a new lead in 3 patients. During a system revision, one new electrode was implanted. The overall leads inserted were 204. There were 33 initial unsuccessful attempts in 22/119 patients. US-guided axillary access was finally successful in 94.9% of patients (113/119). In the other cases (6/119), cephalic vein was isolated or blinded subclavian puncture was performed. Interestingly, at univariate analysis, an increasing BMI and BSA, male sex, and anticoagulant therapy were predictors of unsuccessful attempts or failure to cannulate the vein with US. Among those subjects, the multivariate logistic regression showed significant correlations only between BMI and unsuccessful attempts: odds ratio (OR) = 1.16, p = 0.009 [95% CI = 1.04–1.31], and BMI with failure to cannulate the vein: OR = 1.21, p = 0.03 [95%CI = 1.01–1.45]. The receiver operating characteristic (ROC) curves individuated the best BMI value cutoff point at 27 kg/m2 (area under the curve [AUC]: 68.6%) having a sensitivity of 63.6% and a specificity of 66.5% for unsuccessful puncture attempts; a BMI value of 28 kg/m2 (AUC 74.9%) had a sensitivity of 66.7% and a specificity of 66.7% for failure to cannulate the vein with the US-guided approach. Axillary vein long-axis (in-plane) US-guided cannulation during CIEDs implantation is characterized by a high success rate (94.9%). An elevated BMI is significantly related to unsuccessful puncture attempts or failure to cannulation. The higher is the BMI, the more are the chances to have difficult vein puncture or cannulation failure and to switch from US-guided approach to another technique.

The paper presents a numerical study on electrodynamic behavior of the inter-pancake twin-box joints of the Poloidal Field (PF) coils of the ITER Magnet System. This work was carried out with the THELMA code, developed at the University of Bologna. The THELMA model was adapted to describe both the superconducting wires and the resistive saddle of the joint in a set of reference configurations representative of a set of experimental tests performed on a joint sample at the SULTAN facility in Villigen, Switzerland. The model was applied to analyze both the DC joint resistance measurements and the AC loss vs frequency curve, in order to obtain a full representation of the joint electromagnetic behavior. The paper reports a comparison between the numerical and experimental results and parametric studies on the impact of the main model parameters on the loss vs frequency curve.

High-current and high-field superconducting magnets sustain huge electromagnetic loads. On top of that, the high field constraint pushes towards the use of high-performing superconducting Nb3Sn strands, which are strain sensitive. In recent fusion magnets, the loads reach few hundreds of kN/m in static and sometimes cyclic regimes. These loads modify the strands local strain state and the overall mechanical properties of the cable. In this article, the finite element mechanical code MULTIFIL is applied to model an ITER Cable-In-Conduit Conductor (CICC) petal for the Toroidal Field (TF) coil under operating loadings. The local strain maps and the macroscopic mechanical behavior of the cable are analyzed for both thermal and electromagnetic loadings. A possible explanation for the initial drop of the current sharing temperature observed in some of the TF CICCs tested in the SULTAN facility (PSI, Villigen) is proposed. The impact of important model parameters, such as the void fraction and the friction coefficient between strands, on the mechanical behavior of the conductor is investigated.

Le università rivestono un ruolo fondamentale per un territorio, oltre ad essere un luogo di alta formazione e quindi di creazione di capitale umano, la letteratura ha evidenziato che tali istituzioni attraverso il knowledge spillover possono talvolta rappresentare il motore dell’innovazione e quindi dello sviluppo economico (Wolfe 2005). Nonostante queste importanti funzioni, per garantirsi le risorse necessarie a portare avanti la propria attività le università italiane hanno un crescente bisogno di sviluppare la propria capacità di allargare il bacino di attrazione degli studenti, in quanto: i) parte della quota base del Fondo di Funzionamento Ordinario (FFO) ricevuta dal Ministero dell’Università e della Ricerca dipende dal numero di studenti; ii) maggiore è la platea studentesca, più ampie saranno le entrate dirette dovute alle contribuzioni; iii) la mobilità in entrata da stati esteri viene incentivata attraverso la quota premiale dell’FFO . Questo lavoro mira a fornire un’analisi esplorativa dei flussi delle matricole in uscita dalla Sardegna verso le regioni del Centro-Nord. Si ritiene infatti che prima di rispondere alla domanda “perché gli studenti vanno via?”, si debba sapere quanti sono e dove vanno. Possedere tale informazione rappresenterebbe infatti un prerequisito per una successiva analisi conoscitiva – che qui non affronteremo per ragioni di spazio – della offerta formativa delle università di arrivo.

The populations of economically developed countries are rapidly aging. This represents a sign of demographic success but at the same time it poses several problems for these societies, among which would be an eventual loss of entrepreneurial spirit. Concomitant with the latter idea, the body of empirical literature has shown that the probability of starting a business seems to increase with age up to a threshold point (between 35 and 44 years of age) and to decrease thereafter. However, this does not automatically imply that the innovative attitude of those who opt for an entrepreneurial career in an older population is lower than that characterizing a younger population. One may, indeed, surmise that more efforts will be exerted to introduce innovations as a strategy to compensate the negative effects produced by the shrinking in labor force size and in human capital productivity. Establishing whether population aging has an impact on the innovation attitude of entrepreneurs is crucial to offering a better understanding of the ways through which aging my affect economic growth. In the present paper, we implement a cross-country analysis aimed at answering the following research questions: are older individuals characterized by a lower probability of becoming entrepreneurs? If this turns out to be true, then are the entrepreneurs operating in older societies less or more prone to innovate?

The concentration of births on working days compared to a relative lack of events at weekends or during public holidays has been interpreted in literature as evidence of an excessive appeal to elective delivery. The World Health Organization has repeatedly expressed concerns about the abuse of this practice. We investigate the daily distribution of births in Italy in the period 1999–2016 to answer the following question: In addition to the weekend effects found in other countries, do popular beliefs about “unlucky” days also influence the calendar of births? We assume that without the effects exerted by the working calendar and/or by popular beliefs, the births should be equally distributed between the days of a month. We interpret the equal distribution as the expected one. This allows us to calculate a daily excess of births with respect to the expected number. We evaluate, by the means of multivariate regression, the impact of public holidays and of popular beliefs on the daily excess of births. In addition to working calendar effects, we found a depressing effect exerted by the 17th day of each month in all Italian territories. Indeed, the number 17 is considered extremely unlucky by popular tradition in Italy. We believe that these findings are indicative of a systemic abuse of elective delivery, especially in Southern Italy. To the best of our knowledge, this work is the first to analyze the effect of irrational beliefs on the calendar of births.

Objective: The aim of this paper is to study the selection effects of mortality among soldiers in WWI. Methods: Individual-level data of more than 62,000 soldiers born between 1874 and 1899 in north-eastern Italy was used. Almost 10Š of these soldiers died in the war. A data set was constructed by linking two different sources, the call-up registers and the Roll of Honour of the fallen Italian soldiers of WWI. Results: The risk of death of soldiers in war depended partly on the soldier's assignment to corps and partly on personal behaviour and individual characteristics. A relatively small number of soldiers of large body size fell in battle. The most universal cause of death was illness. Literate soldiers were less likely to die in captivity. Contribution: The concept of mortality differential has rarely been applied to soldiers engaged in conflict. This is because they were supposed to experience similar perils and run similar risks during the war. However, our study found evidence of strong mortality differentials among soldiers, which were strictly associated with the striking differences in terms of literacy, education, and socio-economic status that permeated the Italian society of that time and that the universal enrolment allowed to highlight.

Rutherford cables for particle accelerator magnets are subjected to time dependent magnetic fields during the typical accelerator operating cycle, which in turn induce coupling currents flowing in the loops formed at the contacts between different strands. An analysis of the magnitude and losses associated with these coupling currents is relevant to the design of field quality and cryogenic heat loads. The models reported in the literature exhibit some limits related to computational burden when applied to the analysis of interstrand coupling currents for real cable geometries, and conceptual limits when trying to couple different physical simulations. To solve this problem, a continuum model of Rutherford cables was improved to account for the non-uniform contact conductances between the strands along the cable length, also developing a novel strategy for the computation of the induced voltages. Thanks to these features we attain the required level of detail in the description of the short-range interstrand currents, which could not be properly computed with earlier versions of the continuum model. The model was validated by comparison with analytical results available in the literature for simplified case studies with uniform magnetic field applied orthogonal to the cable. Examples of current and loss distributions are presented in the paper, to prove the potential of the model to analyze Rutherford cables of any configuration. A study regarding the proper choice of the boundary conditions of the problem is presented, which suggests the need for experimental investigation on the actual distribution of currents and losses in the long cable lengths used in accelerator magnets.

The discharge behavior of electrochemical solid state batteries can be conveniently studied by means of electrical analogical models. This paper builds on one of the best known models proposed in the literature for lead-acid electrochemistry (the Ceraolo's model) by formulating an alternative third-order model and implementing a methodology to compute all model parameters (using particle swarm and nonlinear programming optimization) with increased precision and full usability over the whole range of possible states of charge and discharge currents. The developed methodology is used efficiently to model all commercial lead-acid batteries and enable their integration into simulation software for the optimized design of energy systems using energy storage.

Background In patients with end stage renal disease and atrial fibrillation (AF), undergoing chronic dialysis, direct oral agents are contraindicated and warfarin does not fully prevent embolic events while increasing the bleeding risk. The high hemorrhagic risk represents the main problem in this population. Aim of the study was to estimate the safety and efficacy for thromboembolic prevention of left atrial appendage (LAA) occlusion in a cohort of dialysis patients with AF and high hemorrhagic risk. Methods Ninety-two dialysis patients with AF who underwent LAA occlusion were recruited. For comparative purposes, two cohorts of dialysis patients with AF, one taking warfarin (oral anticoagulant therapy, OAT cohort, n = 114) and the other not taking any OAT (no-therapy cohort, n = 148) were included in the study. Primary endpoints were (1) incidence of peri-procedural complications, (2) incidence of 2-year thromboembolic and hemorrhagic events, (3) mortality at 2 years. In order to evaluate the effect of the LAA occlusion on the endpoints with respect to the OAT and No-therapy cohorts, a multivariable Cox regression model was applied adjusted for possible confounding factors. Results The device was successfully implanted in 100% of cases. Two major peri-procedural complications were reported. No thromboembolic events occurred at 2-year follow-up. The adjusted multivariable Cox regression model showed no difference in bleeding risk in the OAT compared to the LAA occlusion cohort in the first 3 months of follow-up [HR 1.65 (95% CI 0.43–6.33)], when most of patients were taking two antiplatelet drugs. In the following 21 months the bleeding incidence became higher in OAT patients [HR 6.48 (95% CI 1.32–31.72)]. Overall mortality was greater in both the OAT [HR 2.76 (95% CI 1.31–5.86)] and No-Therapy [HR 3.09 (95% CI 1.59–5.98)] cohorts compared to LAA occlusion patients. Conclusions The study could open the way to a non-pharmacological option for thromboembolic protection in dialysis patients with AF and high bleeding risk.