A possible application of self-propelling particles is the transport of microscopic cargo. Maximizing the collection and transport efficiency of particulate matter requires the area swept by the moving particle to...
The motion of a solid, infinitely long cylinder perpendicular to a convective liquid-gas interface due to thermocapillarity is investigated via an analytical model. If the cylinder temperature differs from the bulk temperature, a temperature gradient exist along the liquid-gas interface. This results in surface tension gradients at the liquid-gas interface, causing fluid flow around the particle which induces propulsion. For small particles, and thus small Péclet and Reynolds numbers the steady-state equations for temperature and flow fields are solved exactly using two-dimensional bipolar cylindrical coordinates. The velocity of the cylinder as a function of separation distance from the liquid-gas interface is determined for the case of a constant temperature or a constant heat flux on the surface of the cylinder. A larger temperature gradient at the liquid-gas interface in the latter system leads to a larger cylinder velocity and a higher propulsion efficiency. The thermocapillary effect result in larger force on a cylinder than forces arising from other self-propulsion mechanisms.
Introduction: The cerebrospinal fluid (CSF) circulates through the ventricles and the cranial and spinal subarachnoid spaces that are dynamic compartments. According to MONROE-KELLIE's doctrine, the CSF is distributed constantly in compartments which interact with each other. What happen in the other compartments and the CSF flow when laterals ventricles dilate? Methods: 10 hydrocephalus patients underwent a 3T MRI with morphological and phase contrast sequences to investigate the CSF volume and its flow at the aqueductal (SVaque) and spinal (SVspine) levels. The volume of each CSF compartments lateral ventricles (LV), intracranial spaces (IV) (pontine and cerebellum cisterns) and spinal spaces (SS), were estimated by measuring the CSF area in a selected plane crossing each compartment. CSF areas measurements of each patient were normalized to show the distribution of one CSF compartment in front of another. An Heterogeneity coefficient was calculated based on the standard deviation. Results: In our population LV area presented the high heterogeneity 49%, IV heterogeneity was equal to 27% and heterogeneity for the SS was equal to 41%. Paradoxically increase of the LV compartment seems to induce an increase of the IV spaces and indeterminate change in SS which can increase or decrease a lot. SVaque was positively correlated with LV area (R = 0.63, p = 0.04) whereas SVspine presented no significant correlation with LV area. No significant correlations were measured between CSF flows and the all others areas of CSF. Conclusions: Unlike MONROE-KELLIE's doctrine, the compartments can all increase, so it's the tissue or the venous which should decrease. A2 Excess mortality associated with shunt-dependent hydrocephalus following aneurysmal subarachnoid hemorrhage: a population based study
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.