Neutron diffraction with HD isotope substitution has been used to study the formation and decomposition of the methane clathrate hydrate. Using this atomistic technique coupled with simultaneous gas consumption measurements, we have successfully tracked the formation of the sI methane hydrate from a water/gas mixture and then the subsequent decomposition of the hydrate from initiation to completion. These studies demonstrate that the application of neutron diffraction with simultaneous gas consumption measurements provides a powerful method for studying the clathrate hydrate crystal growth and decomposition. We have also used neutron diffraction to examine the water structure before the hydrate growth and after the hydrate decomposition. From the neutron-scattering curves and the empirical potential structure refinement analysis of the data, we find that there is no significant difference between the structure of water before the hydrate formation and the structure of water after the hydrate decomposition. Nor is there any significant change to the methane hydration shell. These results are discussed in the context of widely held views on the existence of memory effects after the hydrate decomposition.

No abstract

AREVA has developed a new coupled neutronics/thermal-hydraulics code system, ARCADIA®. It makes use of modern computing resources to enable more realistic reactor analysis as improved understanding of nuclear reactor behavior is the basis for efficient margin management, i.e. optimization of safety and performance. One of the principal components of this new system is the core simulator, ARTEMIS™. The purpose of this paper is to recall its features, present the latest developments and give a summary of the validation tests.

No abstract

Introduction High voltage electrical injuries have been called “the grand masquerader”, and significant neurological sequalae have been described. Here, we report the case of a 73-year-old man who sustained a 14.5% total body surface area (TBSA) full thickness electrical burns, most significantly to his scalp (Figure 1). On initial evaluation, there was concern for loss of proprioception resulting in gait instability. A magnetic resonance image (MRI) of the cervical spine performed on post injury day 9 showed no evidence of cervical spinal cord injury. Methods A novel descriptive case report of a high-voltage electrical injury with incomplete spinal cord injury Results The patient underwent several operative interventions for wound coverage and preservation of function with the known challenges experienced with high voltage burn wounds. Despite lack of imaging confirmation, suspicion for an occult neurological injury remained high. Neurological consultation confirmed limited proprioception and loss of 2-point discrimination. Due to these specific findings that resulted in an inability to make significant rehabilitation gains, a subsequent MRI of his cervical spine performed on post-injury day 30 demonstrated T2 hyperintensity in the dorsal column in the cervical spine at the C2-3 and C5-6 levels, suggestive of myelopathy (Figure 2). Conclusions To our knowledge, this is the first reported case of an incomplete spinal cord injury (posterior spinal cord syndrome in this case) due to an electrical injury without bony abnormality the association of paralysis. With the knowledge of this injury, our burn therapists have been able to develop a rehabilitation plan with reasonable expectation and goals. While discussing prognosis with the patient and his family, we noted the absence of data regarding outcomes after injuries of this nature and sought to contribute to the literature with this case. Applicability of Research to Practice A novel case of delayed imaging confirmation of posterior cord syndrome contributes to the body of evidence for neurological sequelae due to electrical injuries.