Thermal Performance of the Supporting System for the Large Hadron Collider (LHC) Superconducting Magnets

The LHC collider will be composed of approximately 1700 main ring superconducting magnets cooled to 1.9 K in pressurised superfluid helium and supported within their cryostats on low heat in-leak column-type supports. The precise positioning of the heavy magnets and the stringent thermal budgets imposed by the machine cryogenic system, require a sound thermo-mechanical design of the support system. Each support is composed of a main tubular thin-walled structure in glass-fibre reinforced epoxy resin, with its top part interfaced to the magnet at 1.9 K and its bottom part mounted onto the cryostat vacuum vessel at 293 K. In order to reduce the conduction heat in-leak at 1.9 K, each support mounts two heat intercepts at intermediate locations on the column, both actively cooled by cryogenic lines carrying helium gas at 4.5-10 K and 50-65 K. The need to assess the thermal performance of the supports has lead to setting up a dedicated test set-up for precision heat load measurements on prototype supports. This paper presents the thermal design of the support system of the LHC arc magnets. The results of the thermal tests of a prototype support made in industry are illustrated and discussed. A mathematical model has been set up and refined by the comparison with test results, with the scope of extrapolating the observed thermal performance to different geometrical and material parameters. Finally, the calculated estimate of the heat load budgets of the support system and their contribution to the total cryogenic budget for an LHC arc are presented

Cryogenic R&D at the CERN Central Cryogenic Laboratory

The Central Cryogenic Laboratory operates since many years at CERN in the framework of cryogenic R&D for accelerators and experiments. The laboratory hosts several experimental posts for small cryogen ic tests, all implemented with pumping facility for GHe and vacuum, and is equipped with a He liquefier producing 6.105 l/year, which is distributed in dewars. Tests include thermomechanical qualifica tion of structural materials, cryogenic and vacuum qualification of prototypes, evaluation of thermal losses of components. Some of the most relevant results obtained at the laboratory in the last yea rs are outlined in this paper

Quantitative and Qualitative tools for a physical education program that increases inclusion of children with disabilities

Aim: New technologies in PE provide children with the opportunity (a) to improve motor learning and self-efficacy, (b) model and stucture new prospective of the educational process (Clapham et al.,2015). The purpose of this study is to evalute and compare (a) the development of motor coordination of primary school\u2019s children in relation to BMI, (b) effects of strategies that utilize interactive video game technology (T0 vs T1), (c) enjoyment and physical selfefficacy between EG and CG. Methods: The study has been conducted in a primary school of Puglia, Italy. The sample includes 65 children, separated into two groups in relation to sex and BMI: EG (M: 22, age,10.09 \ub1 0.30; F:19, age 10.10 \ub1 0.31) and CG (M: 12, age, 10 \ub1 0.42; F: 12, age 10 \ub1 0.0). The experimental program consists of 10 lessons, using specialised interactive video game technology to point out unusual motor responses. For the CG has been used teaching styles of production. The following tests have been proposed before and after the intervention: MOBAK 5 (Hermann and Seelig 2016), PSP_C (physical self-efficacy) and PACES (enjoyment). Results: Besides the descriptive statistics (M \ub1 DS), T-test was used in order to highlights significative differences between T0-T1, indipendently from sex differences. The significance value was set at p\0.05. Data analysis revealed significative differences between EG for boys and girls about (a) Control Object and Self-Movement (p\0.05); (b) and physical self efficacy scale (p\0.05). Conclusions: The use of modern technologies and different teaching styles in PE promote motor learning and self-efficacy in children. The trail of new and different instruments are needed to enhance educational environments and develop intrinsic motivation to motor activities. References 1. Clapham, E.D. et al. (2015). The Physical Educator. 72,1, 102\u2013116. 2. Hermann, C. & Seelig, H. (2016). Sportwissenschaft

Status of the HIE-ISOLDE project at CERN

The HIE-ISOLDE project represents a major upgrade of the ISOLDE nuclear facility with a mandate to significantly improve the quality and increase the intensity and energy of radioactive nuclear beams produced at CERN. The project will expand the experimental nuclear physics programme at ISOLDE by focusing on an upgrade of the existing Radioactive ion beam EXperiment (REX) linac with a 40 MV superconducting linac comprising thirty-two niobium-on-copper sputter-coated quarter-wave resonators housed in six cryomodules. The new linac will raise the energy of post-accelerated beams from 3 MeV/u to over 10 MeV/u. The upgrade will be staged to first deliver beam energies of 5.5 MeV/u using two high-$\beta$ cryomodules placed downstream of REX, before the energy variable section of the existing linac is replaced with two low-$\beta$ cryomodules and two additional high-$\beta$ cryomodules are installed to attain over 10 MeV/u with full energy variability above 0.45 MeV/u. An overview of the project including a status summary of the different R&D activities and the schedule will outlined.Comment: 7 pages, 12 figures, submitted to the Heavy Ion Accelerator Technology conference (HIAT) 2012, in Chicag

Heat Flow Measurements on LHC Components

The refrigeration and liquefaction capacity necessary to operate at 1.9 K the 27 km long string of superconducting magnets of the LHC has been determined on the basis of heat load estimates, including static heat inleaks from ambient temperature, resistive heating and dynamic beam-induced heat loads. At all temperature levels, the static heat inleaks determine at least one third of the total heat loads in nominal operating conditions of the machine. Design validation of individual cryocomponents therefore requires a correct estimate of the heat inleaks they induce at all temperature levels, in order not to exceed the allocated heat budget. This paper illustrates the measurements of heat inleaks for several cold components of the future machine, including insulating supports, radiation shields, multi-layer insulation, instrumentation current leads. Distinct methods to determine the heat flow are chosen, depending on the expected heat loads, the temperature range spanned by the heat intercepts, and the working conditions of the component itself

Coronary blood flow and myocardial ischaemia in hypertension

The aim of this investigation was to study the coronary pressure-flow relationship in 60 patients with chronic arterial hypertension of diverse aetiologies and in 14 normotensive subjects (control group). The hypertensive cohort included 6 patients with isolated systolic hypertension (ISH), 7 renovascular hypertensive patients with abnormally elevated angiotensin II plasma levels but without electrocardiographic and/or echocardiographic evidence of left ventricular hypertrophy (LVH) and 47 subjects with essential hypertension (EH), 21 of whom had LVH by electrocardiogram and/or echocardiogram. In the hypertensive cohort a Frank-Starling-like curve was found to describe the coronary pressure-flow relationship when the baseline values for coronary sinus blood flow (CBF, intravascular Doppler technique) were plotted against mean aortic pressure (intra-arterial blood pressure). In particular, the descending limb of such a curve represented a critical region where CBF was "inappropriately" low with respect to perfusion pressure. It was thus concluded that this inability of the heart to adapt CBF to its needs might account for the higher propensity to develop myocardial ischaemia encountered in severe essential hypertensive subjects with concomitant LVH and renovascular hypertensive patients

CT-guided methylene-blue labelling before thoracoscopic resection of pulmonary nodules.

OBJECTIVE: Evaluation of the efficiency of our technique of methylene-blue labelling of pulmonary nodules to facilitate thoracoscopic recognition and excision. DESIGN: Patients with a peripheral pulmonary nodule smaller than 2.5 cm and not in contact with the visceral pleura were included. Under tomodensitometric guidance, the nodules were labelled with methylene-blue within hours before thoracoscopic wedge resection. If frozen section revealed a primary bronchial carcinoma, thoracotomy and classical resection were performed during the same anesthesia. RESULTS: Between July 1992 and August 1996, 54 nodules were removed in 51 patients. Labelling was performed between 75 and 270 min before surgery and was complicated in 13 patients (25.4%) by a small pneumothorax without any clinical consequence. Labelling allowed successful thoracoscopic recognition of 50 nodules (92%) and thoracoscopic wedge resection was possible in all but one cases (91%). Five patients (9%) required thoracotomy. Histology showed a benign lesion in 22 cases, a primary lung carcinoma in 17 and a metastases in 15. Twenty of the 22 benign nodules (91%) were removed without thoracotomy. According to the protocol, 13 patients with a primary lung tumour underwent lobectomy during the same session. There was no mortality nor morbidity amongst patients who had thoracoscopy only. CONCLUSIONS: Our technique of labelling peripheral pulmonary nodules with methylene-blue is very effective and is not associated with any relevant complication. Thoracoscopic excision and diagnosis is possible in more than 90% of the cases. We therefore recommend this simple, low-cost and reliable technique for nodules not in contact with the visceral pleura before thoracoscopic wedge resection

“CoVidentary”: An online exercise training program to reduce sedentary behaviours in children with type 1 diabetes during the COVID-19 pandemic

Aim: We explored the physical activity (PA) level and the variation in glycaemic control in children with type 1 diabetes (T1D) before and during the lockdown. Then, we proposed an online training program supported by sport-science specialists. Methods: Parents of children with T1D (<18 years) filled out an online survey. Anthropometric characteristics, PA, play, sport and sedentary time and the medical related outcomes were recorded. An adapted online program “Covidentary” was proposed through full-training (FT) and active breaks (AB) modality. Results: 280 youth (11.8 ± 3.3 years) were included in the analysis. We reported a decline in sport (-2.1 ± 2.1 h/week) and outdoor-plays (-73.9 ± 93.6 min/day). Moreover, we found an increase in sedentary time (+144.7 ± 147.8 min/day), in mean glycaemic values (+25.4 ± 33.4 mg/dL) and insulin delivery (71.8% of patients). 37% of invited patients attended the training program, 46% took part in AB and 54% in FT. The AB was carried out for 90% of the total duration, while the FT for 31%. Both types of training were perceived as moderate intensity effort. Conclusion: A decline of participation in sport activities and a subsequent increase of sedentary time influence the management of T1D of children, increasing the risk of acute/long-term complications. Online exercise program may contrast the pandemic's sedentary lifestyle