Asymmetric toroidal eddy currents (ATEC) to explain sideways forces at JET

During some JET vertical displacement events (VDEs) plasma current and position are found to be toroidally asymmetric. When asymmetries lock, the vessel has been observed to move horizontally, consequently strong horizontal forces are expected following plasma asymmetries, whether locked or rotating. The cause of horizontal forces is, as already identified in previous works, the asymmetric circulation of current in the structures. The physics mechanism responsible for these asymmetric currents is instead an open issue and it is the object of the present analysis. In particular it will be shown that the asymmetry is not due to a direct exchange of current between plasma and structure (as in the case of halo currents) but to asymmetric conductive paths which arise, in the structures, when the plasma column asymmetrically wets the wall. Simulations of this phenomenon using finite element (FE) models have been conducted to reproduce the JET observation during locked and rotating asymmetric VDEs. Estimated sideways force, asymmetry (I p asym) and normalized asymmetry (Ap asym) of plasma current, vertical position at different toroidal locations during the disruption and halo current asymmetry have been compared with measurements done at JET during upward AVDEs. The substantial match between experiments and simulations confirms the soundness of the assumptions. Furthermore, the same physical model applied to downward VDEs shows that divertor support and coils, together with the geometry of the limiting surfaces, considerably lessen asymmetric loads as experienced at JET after installing those components.EURATOM 63305

EM zooming procedure in ANSYS Maxwell 3D

The severity of electromagnetic (EM) loads produced by plasma disruptions is one of the most concerning issues for the ITER in-vessel components design. To investigate the effects of fast EM transients on plasma surrounding structures during a disruption the Secondary Excitations (SE) method is used. This is an interface procedure to couple 2D plasma equilibrium codes with Finite Elements (FE) software. The Zooming Approach (ZA) used for the analyses presented here is a particular implementation of the SE method. The aim of this work is the demonstration that the ZA can be effectively applied in case of ANSYS Maxwell 3D analyses combining the ease of use of the Maxwell code with the computational efficiency of the ZA. The work has been carried out evaluating the EM loads acting on the ITER Diagnostic Equatorial Port Plug (EPP) during major disruptions scenario and comparing these loads with those obtained in previous analyses. Additional analyses have been performed to study the effect of ferromagnetic materials on EM loads in order to investigate ANSYS Maxwell capabilities in simulating non-linear magnetic properties

Maternal personality profile of children affected by migraine

Background: Empirical evidence of the important role of the family in primary pediatric headache has grown significantly in the last few years, although the interconnections between the dysfunctional process and the family interaction are still unclear. Even though the role of parenting in childhood migraine is well known, no studies about the personality of parents of migraine children have been conducted. The aim of the present study was to assess, using an objective measure, the personality profile of mothers of children affected by migraine without aura (MoA). Materials and methods: A total of 269 mothers of MoA children (153 male, 116 female, aged between 6 and 12 years; mean 8.93 ± 3.57 years) were compared with the findings obtained from a sample of mothers of 587 healthy children (316 male, 271 female, mean age 8.74 ± 3.57 years) randomly selected from schools in the Campania, Umbria, Calabria, and Sicily regions. Each mother filled out the Minnesota Multiphasic Personality Inventory – second edition (MMPI-2), widely used to diagnose personality and psychological disorders. The t-test was used to compare age and MMPI-2 clinical basic and content scales between mothers of MoA and typical developing children, and Pearson’s correlation test was used to evaluate the relation between MMPI-2 scores of mothers of MoA children and frequency, intensity, and duration of migraine attacks of their children. Results: Mothers of MoA children showed significantly higher scores in the paranoia and social introversion clinical basic subscales, and in the anxiety, obsessiveness, depression, health concerns, bizarre mentation, cynicism, type A, low self-esteem, work interference, and negative treatment indicator clinical content subscales (P , 0.001 for all variables). Moreover, Pearson’s correlation analysis showed a significant relationship between MoA frequency of children and anxiety (r = 0.4903, P = 0.024) and low self-esteem (r = 0.5130, P = 0.017), while the MoA duration of children was related with hypochondriasis (r = 0.6155, P = 0.003), hysteria (r = 0.6235, P = 0.003), paranoia (r = 0.5102, P = 0.018), psychasthenia (r = 0.4806, P = 0.027), schizophrenia (r = 0.4350, P = 0.049), anxiety (r = 0.4332, P = 0.050), and health concerns (r = 0.7039, P , 0.001) MMPI-2 scores of their mothers. Conclusion: This could be considered a preliminary study that indicates the potential value of maternal personality assessment for better comprehension and clinical management of children affected by migraine, though further studies on the other primary headaches are necessary

CPS Based Liquid Metal Divertor Target for EU-DEMO

AbstractPower exhaust is a key mission in the roadmap to the realization of a future fusion reactor. Among the different solutions, the use of liquid metals as plasma facing materials are of interest due to their potential increased lifetime. Several liquid metal limiters have been successfully tested in the Frascati Tokamak Upgrade over the last 10 years. Liquid materials such as lithium and tin have been investigated using capillary porous systems (CPSs), and their impact on plasma performance has been explored. From such experience, a liquid metal divertor (LMD) concept design, CPS-based, is here proposed. Tin has been preferred as plasma facing material. The proposed LMD would operate, in low evaporative regime, with matching heat exhausting capabilities to those of the baseline ITER-like divertor. Continuous refilling of the CPS is guaranteed with a reservoir at the back of the unit, where the metal is kept liquid through a gas heating circuit. The study has been carried out using ANSYS and the thermal results will be shown. All the design choices are compatible with the current materials and the constraints adopted for the DEMO W divertor. Using such configuration, thermal loads up to 20 MW/m2 are exhausted while keeping the surface temperature below 1250 °C. The design foresees values of pressure, temperature and flow rate of the water coolant in the same range expected for the W DEMO divertor, thus facilitating the integration of such solution in the current cassette design. Technological and practical aspects are addressed, i.e. tin corrosion and CPS wettability. Possible solutions to prevent tin corrosion, and its compatibility with structural materials, will be outlined

Pediatric neurofibromatosis 1 and parental stress: a multicenter study

Background: Neurofibromatosis 1 (NF1) is a complex and multifaceted neurocutaneous syndrome with many and varied comorbidities. The literature about the prevalence and degree of maternal stress and the impact of NF1 in the parent–child interaction is still scant. The aim of this study was to evaluate the prevalence of maternal stress in a large pediatric sample of individuals affected by NF1. Methods: Thirty-seven children (19 boys, 18 girls) of mean age 7.86±2.94 (range 5–11) years affected by typical NF1 and a control group comprising 405 typically developing children (207 boys, 198 girls; mean age 8.54±2.47 years) were included in this study. To assess parental stress, the mothers of all individuals (NF1 and comparisons) filled out the Parenting Stress Index-Short Form test. Results: The two study groups were comparable for age (P=0.116), gender (P=0.886), and body mass index adjusted for age (P=0.305). Mothers of children affected by NF1 reported higher mean Parenting Stress Index-Short Form scores on the Parental Distress domain (P,0.001), Difficult Child domain (P,0.001), and Total Stress domain than the mothers of typically developing children (controls) (P,0.001). No significant differences between the two groups were found for the Parent-Child Dysfunctional Interaction domain (P=0.566) or Defensive Responding domain scores (P=0.160). Conclusion: NF1 is considered a multisystemic and complex disease, with many still unrecognized features in pediatric patients and in their families. In this light, our findings about the higher levels of maternal stress highlight the importance of considering the environmental aspects of NF1 management in developmental age

Depressive symptoms and childhood sleep apnea syndrome

BACKGROUND: The relationship between sleep and mood regulation is well known, and some reports suggest a key role of sleep-related breathing disorders (SRBD) in the development of the symptomatology of depression, even if no conclusive data are actually found in the clinical literature. The aim of this study was to assess the relationship between SRBD and depressive symptoms in a population of school-aged children. METHODS: The study population comprised 94 children affected by SRBD and 107 healthy children. To identify the severity of SRBD, an overnight respiratory evaluation was performed. All subjects filled out the Italian version of the Children Depression Inventory (CDI) to screen for the presence of depressive symptoms. RESULTS: The group with SRBD showed higher CDI scores than the group without SRBD, with a positive correlation found between CDI scores, apnea-hypopnea index, and oxygen desaturation index values. Logistic regression showed that an apnea-hypopnea index ≥ 3 and an oxygen desaturation index ≥ 1 could be risk factors for development of depressive symptoms. According to receiver-operating characteristic curve analysis, the cutoff point for the apnea-hypopnea index that could cause a pathological CDI score (≥19) was >5.66, and the cutoff point for the oxygen desaturation index was >4.2. The limitations of this study are that our data are derived from one single psychometric test and not from a complete psychiatric evaluation, and our subjects came from a small group in southern Italy. CONCLUSION: Our results suggest the importance of mood assessment in children affected by SRBD

Memory performances and personality traits in mothers of children with obstructive sleep apnea syndrome

Background: Chronic diseases in pediatric age have been identified as stressful risk factors for parents. Studies on caregivers have documented the impact of chronic parenting stress on emotion and cognition.Aim: To investigate the differences between a group of mothers of children affected by obstructive sleep apnea syndrome (OSAS) for at least 4 years and a group of mothers of typically developing children (TDC) in relation to parental stress, self-esteem, locus of control, and memory performances.Methods: A group of 86 mothers (mean age 35.6 +/- 4.9, ranged between 32 and 41 years) of children with OSAS diagnosis, and a group of 52 mothers of TDC (mean age 35.9 +/- 4.2, ranged between 32 and 41 years) participated in the study. All participants were administered stress level, global self-esteem, internal/external locus of control scales, and memory assessment.Results: Mothers of OSAS children, compared to mothers of TDC, had a significantly higher level of stress, lower self-esteem, more external locus of control and poorer memory performance.Conclusions: The child respiratory disease, with its sudden and unpredictable features, appeared as a significant source of stress for the mother. Such stress condition may have an impact on mothers' personality traits (self-esteem, locus of control) and on their memory performances. The data have suggested a need for psychological support programs for mothers to better manage stress associated with children's respiratory disease