Fragments Generated during Liquid Hydrogen Tank Explosions

Liquid hydrogen (LH2) may be employed to transport large quantities of pure hydrogen or be stored onboard of ships, airplanes and trains fuelled by hydrogen, thanks to its high density compared to gaseous compressed hydrogen. LH2 is a cryogenic fluid with an extremely low boiling point (-253°C at atmospheric pressure) that must be stored in double-walled vacuum insulated tanks to limit the boil-off formation. There is limited knowledge on the consequences of LH2 tanks catastrophic rupture. In fact, the yield of the consequences of an LH2 tank explosion (pressure wave, fragments and fireball) depend on many parameters such as tank dimension, filling degree, and tank internal conditions (temperature and pressure) prior the rupture. Only two accidents provoked by the rupture of an LH2 tank occurred in the past and a couple of experimental campaigns focussed on this type of accident scenario were carried out for LH2. The aim of this study is to analyse one of the LH2 tank explosion consequences namely the fragments. The longest horizontal and vertical ranges of the fragments thrown away from the blast wave are estimated together with the spatial distribution around the tank. Theoretical models are adopted in this work and validated with the experimental results. The proposed models can aid the risk analysis of LH2 storage technologies and provide critical insights to plan a prevention and mitigation strategy and improve the safety of hydrogen applications

Update on safety during pregnancy of biological agents and some immunosuppressive anti-rheumatic drugs

A consensus paper concerning the interaction of anti-rheumatic drugs and reproduction was published in 2006, representing data collected during the year 2004 and 2005. Because of an increasing use of biological agents in women of fertile age, the information was updated for the years 2006 and 2007. Experts disagree whether TNF-inhibitors should be stopped as soon as pregnancy is recognized or may be continued throughout pregnancy. Pregnancy experience with abatacept and rituximab is still too limited to prove their safety for the developing fetus. They must be withdrawn before a planned pregnancy. LEF has not been proven to be a human teratogen. Registries of transplant recipients have shown that cyclosporin (CsA) and tacrolimus do not increase the rate of congenital anomalies, whereas mycophenolate mofetil (MMF) clearly carries a risk for congenital anomalies. Prophylactic withdrawal of drugs before pregnancy is mandatory for abatacept, rituximab, LEF and MMF. Data remain insufficient for gonadal toxicity of immunosuppressive drugs in men and for excretion of these drugs in human breast mil

Update on safety during pregnancy of biological agents and some immunosuppressive anti-rheumatic drugs

A consensus paper concerning the interaction of anti-rheumatic drugs and reproduction was published in 2006, representing data collected during the year 2004 and 2005. Because of an increasing use of biological agents in women of fertile age, the information was updated for the years 2006 and 2007. Experts disagree whether TNF-inhibitors should be stopped as soon as pregnancy is recognized or may be continued throughout pregnancy. Pregnancy experience with abatacept and rituximab is still too limited to prove their safety for the developing fetus. They must be withdrawn before a planned pregnancy. LEF has not been proven to be a human teratogen. Registries of transplant recipients have shown that cyclosporin (CsA) and tacrolimus do not increase the rate of congenital anomalies, whereas mycophenolate mofetil (MMF) clearly carries a risk for congenital anomalies. Prophylactic withdrawal of drugs before pregnancy is mandatory for abatacept, rituximab, LEF and MMF. Data remain insufficient for gonadal toxicity of immunosuppressive drugs in men and for excretion of these drugs in human breast mil

Alpha glucocorticoid receptor expression in different experimental rat models of acute lung injury

Background and objectives: Acute respiratory distress syndrome (ARDS) is a frequent form of hypoxiemic respiratory failure caused by the acute development of diffuse lung inflammation. Dysregulated systemic inflammation with persistent elevation of circulating inflammatory cytokines is the pathogenetic mechanism for pulmonary and extrapulmonary organ dysfunction in patients with ARDS. Glucocorticoids (GCs) have a broad range of inhibitory inflammatory effects, including inhibition of cytokines transcription, cellular activation and growth factor production. They inhibit the inflammatory pathways through two specific intracellular glucocorticoid receptors (GRs), named GRα and GRβ. The aim of our study was to evaluate the histologic evidence of inflammatory injury and the GRα uptake of resident and inflammatory cells in different experimental models of acute lung injury (ALI). Methods: We studied four groups of rats: three different experimental rat models of lung injury and a control group. The ALI was caused by barotrauma (due to an overventilation), oleic acid injection and mechanical ventilation. Results were compared to nonventilated rat control group. The duration of mechanical ventilation was of 2.5 h. At the end of each experiment, rats were sacrificed. Lung biopsies were evaluated for morphologic changes. The immunohistochemistry was performed to study GRα expression. Results: Histologic evidence of lung injury (alveolar and interstitial edema, vascular congestion, alveolar haemorrhage, emphysema, number of interstitial cells and neutrophils, and destruction of alveolar attachments) were present in all ventilated groups. Barotrauma lead to an additional inflammatory response. GRα expression significantly increased in the three ventilated groups compared with nonventilated groups. GRα expression was highest in barotrauma group. Conclusions: These data indicate that ALI is associated with diffuse alveolar damage, up-regulation of the inflammatory response and GRα overexpression. Barotrauma is the most effective mechanism inducing acute lung inflammation and GRα overexpression. © 2007 Elsevier Ltd. All rights reserved

Transjugular intrahepatic portosystemic shunt for hepatitis C virus-related portal hypertension after liver transplantation.

hinolfi D, De Simone P, Catalano G, Petruccelli S, Coletti L, Carrai P, Marti J, Tincani G, Cicorelli A, Cioni R, Filipponi F. Transjugular intrahepatic portosystemic shunt for hepatitis C virus-related portal hypertension after liver transplantation. Clin Transplant 2012 DOI: 10.1111/j.1399-0012.2011.01595.x. © 2012 John Wiley & Sons A/S. Abstract:  This is a single center retrospective review of 19 consecutive liver transplant (LT) patients with hepatitis C virus (HCV)-related graft recurrent hepatitis who underwent transjugular intrahepatic portosystemic shunt (TIPS) at a median interval of 21 months (range: 5-50) from LT. Indications were refractory ascites in 11 patients (57.9%), hydrothorax in six (31.6%), and both in two (10.5%). TIPS was successful in 94.7% of cases (18/19) with only one procedure-related mortality (5.3%) owing to sepsis on day 35. At a median follow-up of 23 months (range: one month-nine yr), TIPS allowed for symptoms resolution in 16 patients (84.2%), with ascites resolving in all cases and hydrothorax persisting in 2. Post-TIPS patient survival at six months, one yr, and three yr was 84.2%, 73.7%, and 56.8%, respectively. We compared these results with a control group of 29 patients with HCV recurrence but without unresponsive ascites or hydrothorax. Patients in the control group had better survival than patients undergoing TIPS placement. However, survival of TIPS patients with a MELD score lower than or equal to 12 was similar to that of the control group. We conclude that TIPS may be used to treat complications secondary to HCV

Design of an under-actuated wrist based on adaptive synergies

An effective robotic wrist represents a key enabling element in robotic manipulation, especially in prosthetics. In this paper, we propose an under-actuated wrist system, which is also adaptable and allows to implement different under-actuation schemes. Our approach leverages upon the idea of soft synergies - in particular the design method of adaptive synergies - as it derives from the field of robot hand design. First we introduce the design principle and its implementation and function in a configurable test bench prototype, which can be used to demonstrate the feasibility of our idea. Furthermore, we report on results from preliminary experiments with humans, aiming to identify the most probable wrist pose during the pre-grasp phase in activities of daily living. Based on these outcomes, we calibrate our wrist prototype accordingly and demonstrate its effectiveness to accomplish grasping and manipulation tasks

Hydraulic characterization of the full scale mock-up of the demo divertor outer vertical target

In the frame of the pre-conceptual design activities of the DEMO work package DIV-1 “Divertor Cassette Design and Integration” of the EUROfusion program, a mock-up of the divertor outer vertical target (OVT) was built, mainly in order to: (i) demonstrate the technical feasibility of manufacturing procedures; (ii) verify the hydraulic design and its capability to ensure a uniform and proper cooling for the plasma facing units (PFUs) with an acceptable pressure drop; and (iii) experimentally validate the computational fluid-dynamic (CFD) model developed by the University of Palermo. In this context, a research campaign was jointly carried out by the University of Palermo and ENEA to experimentally and theoretically assess the hydraulic performances of the OVT mock-up, paying particular attention to the coolant distribution among the PFUs and the total pressure drop across the inlet and outlet sections of the mock-up. The paper presents the results of the steady-state hydraulic experimental test campaign performed at ENEA Brasimone Research Center as well as the relevant numerical analyses performed at the Department of Engineering at the University of Palermo. The test facility, the experimental apparatus, the test matrix and the experimental results, as well as the theoretical model, its assumptions, and the analyses outcomes are herewith reported and critically discussed

Entanglement entropy in aperiodic singlet phases

We study the average entanglement entropy of blocks of contiguous spins in aperiodic XXZ chains which possess an aperiodic singlet phase at least in a certain limit of the coupling ratios. In this phase, where the ground state constructed by a real space renormalization group method, consists (asymptotically) of independent singlet pairs, the average entanglement entropy is found to be a piecewise linear function of the block size. The enveloping curve of this function is growing logarithmically with the block size, with an effective central charge in front of the logarithm which is characteristic for the underlying aperiodic sequence. The aperiodic sequence producing the largest effective central charge is identified, and the latter is found to exceed the central charge of the corresponding homogeneous model. For marginal aperiodic modulations, numerical investigations performed for the XX model show a logarithmic dependence, as well, with an effective central charge varying continuously with the coupling ratio.Comment: 18 pages, 9 figure

Maternal neurofascin-specific autoantibodies bind to structures of the fetal nervous system during pregnancy, but have no long term effect on development in the rat

Neurofascin was recently reported as a target for axopathic autoantibodies in patients with multiple sclerosis (MS), a response that will exacerbate axonal pathology and disease severity in an animal model of multiple sclerosis. As transplacental transfer of maternal autoantibodies can permanently damage the developing nervous system we investigated whether intrauterine exposure to this neurofascin-specific response had any detrimental effect on white matter tract development. To address this question we intravenously injected pregnant rats with either a pathogenic anti-neurofascin monoclonal antibody or an appropriate isotype control on days 15 and 18 of pregnancy, respectively, to mimic the physiological concentration of maternal antibodies in the circulation of the fetus towards the end of pregnancy. Pups were monitored daily with respect to litter size, birth weight, growth and motor development. Histological studies were performed on E20 embryos and pups sacrificed on days 2, 10, 21, 32 and 45 days post partum. Results: Immunohistochemistry for light and confocal microscopy confirmed passively transferred anti-neurofascin antibody had crossed the placenta to bind to distinct structures in the developing cortex and cerebellum. However, this did not result in any significant differences in litter size, birth weight, or general physical development between litters from control mothers or those treated with the neurofascin-specific antibody. Histological analysis also failed to identify any neuronal or white matter tract abnormalities induced by the neurofascin-specific antibody. Conclusions: We show that transplacental transfer of circulating anti-neurofascin antibodies can occur and targets specific structures in the CNS of the developing fetus. However, this did not result in any pre- or post-natal abnormalities in the offspring of the treated mothers. These results assure that even if anti-neurofascin responses are detected in pregnant women with multiple sclerosis these are unlikely to have a negative effect on their children