27 research outputs found
Trigeminal neuralgia and persistent trigeminal artery
We report a case of trigeminal neuralgia caused by persistent trigeminal artery (PTA) associated with asymptomatic left temporal cavernoma. Our patient presented unstable blood hypertension and the pain of typical trigeminal neuralgia over the second and third divisions of the nerve in the right side of the face. The attacks were often precipitated during physical exertion. MRI and Angio-MRI revealed the persistent carotid basilar anastomosis and occasionally left parietal cavernoma. After drug treatment of blood hypertension, spontaneous recovery of neuralgia was observed and we planned surgical treatment of left temporal cavernoma
LightWeight Aggregates from industrial and c&D waste recycling: new perspectives for environment safeguard and energy saving
Lightweight aggregates from Industrial waste, perspective and energy savin
Lightweight aggregates from waste materials: Reappraisal of expansion behavior and prediction schemes for bloating
There is a growing concern on lightweight aggregates (LWA) for recycling of waste materials: this
manufacturing technology is considered a flexible tool to make it possible the conversion of large
amounts of residues into building products. The main challenge for this purpose is the control on the
technological behavior during firing of waste-bearing batches. The target is engineering the sintering
and expansion of LWA in order to tailor bulk density, mechanical strength and water absorption on various
possible applications (e.g., structural and non-structural lightweight concretes, lightweight mortars,
filtration substrates, floriculture). The prediction of the aggregate expansion – and hence the batch design
– is usually carried out utilizing the Riley’s and/or Cougny’s schemes, which are based on the bulk chemical
composition of clay bodies. However, collecting the literature data on waste-based LWA and plotting
them in the Riley’s and Cougny’s diagrams, no reliable discrimination turns out between expanding and
non-expanding batches. In the same way, the attempt to modify the Riley’s and Cougny’s parameters,
including elements present in wastes but not in natural raw materials, was unsuccessful. From this standpoint,
a new approach to assess the batch expandability was developed through a deeper comprehension
of mechanisms acting on sintering and expansion of LWA. A specific characterization protocol was set up,
entailing hot-stage microscopy and determination of phase composition and microstructure. This implies
a paradigm shift from batch (chemical composition) to vitreous phase (amount, chemical composition,
and viscosity at high temperature). The vitreous phase plays a key-role for bloating, microstructure
and physical properties of LWA. A working example is presented about new LWA based on waste glasses,
ceramic tile polishing sludge and clay raw materials