Node Cavitation Research Articles

Pipe Burst Risk State Assessment and Classification Based on Water Hammer Analysis for Water Supply Networks

Hydraulic transients pose many risks to urban water distribution systems. The high pressure induced by a hydraulic transient can cause pipe bursts, the negative pressure can cause pipe collapses, cavitation can cause pipeline erosions and pump impeller damages, and the transient forces can loosen pipe joints. We derived the hydraulic calculating equations based on the method of characteristics (MOC) by considering the pipe head loss and node cavitation. Four individual factors and one composite factor for hydraulic transient risk are presented along with the method of calculation of the indicators. They can produce a tabular result that is color coded by risk, and the risk classification map can be built by a four-layer state assessment and color coding technology. They are Class I with green for safe level, Class II with cyan for warning level, Class III with blue for dangerous level, and Class IV with red for severe level. The pipe burst risk assessment methods and procedures are presented. Finally, a sample model and a Chinese city pipe network system are presented for pipe burst risk classification examples.

Fatal CNS vasculopathy in a patient with refractory celiac disease and lymph node cavitation

Celiac disease is an enteropathy occurring in genetically predisposed individuals due to a dietary intolerance to gluten. Patients with celiac disease may develop a neurological disorder of unknown cause, although autoimmune mechanisms are suspected. We report on a 56-year-old man with celiac disease, who became refractory to a gluten-free diet and died of a rapidly progressive encephalopathy. Magnetic resonance imaging indicated focal lesions of the cerebellum and brainstem, and electrodiagnostic studies suggested an axonal neuropathy. Autopsy revealed a flattened small-bowel mucosa with intraepithelial lymphocytosis, a spectrum of degenerative changes of the intra-abdominal and mediastinal lymph nodes, including cavitary degeneration, and splenomegaly. Histologically, the lymph nodes showed pseudocyst formation and lymphocytic vasculitis with fibrinoid necrosis, and sections of the brain exhibited fibrinoid degeneration of small blood vessels, sparse perivascular lymphocytic infiltrates, and perivascular ischemic lesions. Identical T-cell clones were identified in the duodenum, stomach, lymph nodes, and spleen. This patient had an unusual neurological disorder related to a vasculopathy, probably mediated by a circulating neoplastic clone of activated T cells.