A Non-Intrusive Pressure Sensor by Detecting Multiple Longitudinal Waves

Pressure vessels are widely used in industrial fields, and some of them are safety-critical components in the system - for example, those which contain flammable or explosive material. Therefore, the pressure of these vessels becomes one of the critical measurements for operational management. In the paper, we introduce a new approach to the design of non-intrusive pressure sensors, based on ultrasonic waves. The model of this sensor is built based upon the travel-time change of the critically refracted longitudinal wave (LCR wave) and the reflected longitudinal waves with the pressure. To evaluate the model, experiments are carried out to compare the proposed model with other existing models. The results show that the proposed model can improve the accuracy compared to models based on a single wave

Infratentorial superficial siderosis: report of six cases and review of the literature

ObjectivesTo investigate the etiology, clinical manifestations, imaging features, and treatment of patients with infratentorial superficial siderosis (iSS), enhance clinicians' comprehension of this rare disease, and conduct oral deferiprone intervention and subsequent monitoring.MethodsSix patients diagnosed with iSS based on magnetic resonance imaging (MRI) and susceptibility weighted imaging (SWI) were enrolled from 2021 to 2023 at the First Affiliated Hospital of Fujian Medical University. Their clinical datas were summarized, and the etiology and imaging characteristics were analyzed. Follow-up was conducted through telephone or outpatient visits.ResultsAmong the 6 patients, there were 3 males and 3 females. The onset age ranged from 35 to 71 years, with an average onset age of 53 years. The clinical symptoms mainly included acoustic disturbances (6/6), gait imbalance (6/6), dysolfactory (6/6), cognitive impairment (2/6), epilepsy (2/6), and pyramidal tract sign (2/6). Evidence of superficial siderosis was observed on MRI across the cortex, brainstem, cerebellum, and spinal cord in all patients. T2-space sequence MRI revealed two instances of dural tear. During the follow-up period ranging from 1 month to 3 years, three patients who received oral deferiprone treatment showed improvement, whereas the remaining three patients who declined deferiprone treatment demonstrated progression.ConclusionThe primary clinical manifestations of iSS include bilateral sensorineural hearing disturbances, progressive cerebellar ataxia, and spinal cord lesions. The key diagnostic criteria involve the presence of linear hypointensity on T2-WI in the surface region of the nervous system. Dural tear caused by various factors is considered to be the most common cause of iSS, and its treatment mainly involves surgical intervention for hemorrhagic primary diseases as well as pharmacotherapy with deferiprone

Pressure measurement based on multi-waves fusion algorithm

Measuring the pressure of a pressure vessel accurately is one of fundamental requirements of the operation of many complex engineering systems. Ultrasonic technique has been proposed to be a good alteration of non-intrusive measurement. Based on the study of acoustoelastic effect and thin-shell theory, it has been identified that the travel-time changes of the critically refracted longitudinal wave (LCR wave) and other reflected longitudinal waves are all proportional to the inner pressure. Considering the information redundancy in these waves, we proposed an approach for pressure measurement by using the information fusion algorithm on multiple reflected longitudinal waves. In the paper, we discussed the fusion algorithm in details and proposed a pressure measurement model, which represents an accurate relationship between the pressure and the travel-time changes of multiple waves. Through the experiment, the analysis of data collected from experiment system showed that the pressure measurement based on the multi-wave model is notably more accurate than the one based on the single-wave model (the average relative error (ARE) can be less than 7.24% and the root-mean-square error (RMSE) can be lower than 0.3MPa)